Cards from USMLE Practice Tests

Question 1

When deciding which tumor antigen will produce the highest antibody titer, what must you consider?

Answer 1

Whether the immune system will recognize and mount a response to the antigen (i.e. recognize it as “other”).

Question 2

What signaling molecule is most directly associated with in an increase in lytic bone lesions?

Answer 2

Interleukin-1

Question 3

What disease process is mostl likely occuring in a recently-hospitalized patient who presents with oliguria and uricemia?

Answer 3

Acute tubular necrosis

Question 4

Which part of the kidney are necrotic cells most likely to be found in acute tubular necrosis?

Answer 4

The lumen of the proximal tubule

Question 5

Which cells are infected by EBV? Which cells will be abnormal on blood smear?

Answer 5

B cells are infected via CD21

T cells present with reactive cytotoxic abnormality

Question 6

Which drug is a monoclonal antibody against platelet IIb/IIIa receptor? How does it work?

Answer 6

Abciximab. Binds platelet fibrinogen receptor (Gp Iib/IIIa) on activated platelet preventing aggradation.

Question 7

What is the effect of gemfibrozil on cytochrome P450?

Answer 7

It inhibits cytochrome P450.

Question 8

What is pannus? Which disease process is associated with it?

Answer 8

Pannus is proliferative granulation tissue and is found in the setting of rheumatoid arthritis.

Question 9

Where is the thyroid hormone receptor located?

Answer 9

In the nucleus

Question 10

What features would be suggestive of myasthenia gravis in a patient presenting short of breath?

Answer 10

Difficulty taking a long deep breath, decreased tidal volume and vital capacity, symptoms become worse as the day goes on.

Question 11

A new onset nonbacterial endocarditis in a patient with chronic diarrhea raises suspicion for which neoplasms?

Answer 11

Adenocarcinoma of the small intestine

Question 12

What metabolite is responsible for the formation of diabetic cataract?

Answer 12

Sorbitol

Question 13

What is the inheritance pattern of Tay-Sachs disease?

Answer 13

Autosomal recessive

Question 14

What is the embryological origin of the mobile cystic mass on the lateral side of the neck which does not move with swallowing?

Answer 14

A pharyngeal cleft cyst, derived from a persistent cervical sinus. It will open anterior to the sternocleidomastoid muscle.

Question 15

What drug could you use to treat someone who was exposed to paint thinner and is experiencing blurred vision, vomiting, fusion, and difficulty walking?

Answer 15

Fomepizole, an alcohol dehydrogenase inhibitor

Question 16

What is heteroplasmy?

Answer 16

Presence of normal and mutated mitochondrial DNA; variable expression of mitochondrial inherited disease.

Question 17

Where in the kidney does acetazolamide act?

Answer 17

Proximal tubule.

Question 18

What is the mechanism of action of micafungin?

Answer 18

Inhibition of fungal cell wall synthesis (block synthesis of beta-glucan)

Question 19

What is the most common inherited cause of susceptibility to mycobacteria?

Answer 19

IL-12 deficiency (leading to low interferon gamma)

Question 20

Where is the neurovascular bundle located on the rib? What is the relevance for thoracentesis?

Answer 20

The neurovascular bundles located below so the needle has to go above the rib to avoid damage.

Question 21

In a Whipple procedure, which nerve structures can be cut to reduce stomach acid output?

Answer 21

The vagal trunks

Question 22

Which uterine ligament attaches to the cervical region and extends posteriorly?

Answer 22

The uterosacral ligament

Question 23

Which apolipoprotein would mediate a deficiency in absorption of fat-soluble vitamins?

Answer 23

apoB - responsible for packaging of lipids into chylomicrons.

Question 24

What are Bence Jones protein on urinalysis?

Answer 24

Ig light chains, characteristic of multiple myeloma.

Question 25

What is the bronchial circulation?

Answer 25

The systemic vascular supply to the lung

Question 26

Contrast apoptosis and necrosis cell findings.

Answer 26

Apoptosis: eosinophilic cytoplasm, basal ability clears, pyknosis and karyorrhexis.

Necrosis: produces a local inflammatory reaction, not as eosinophilic, nuclei disappear.

Question 27

A deficiency of myeloperoxidase would present with the inability to produce which substance?

Answer 27

Bleach/hypochlorite (hydroxy-halide radical)

Question 28

What is the primary driver behind muscle atrophy in cases of immobilization?

Answer 28

Increase protein degradation

Question 29

What is the mechanism of action and indication of Praziquantel?

Answer 29

Increases calcium permeability and actualization to kill Hellminths.

Question 30

What are the drugs used to treat helminth infections?

Answer 30

Pyrantel pamoate, ivermectin, mebendazole, praziquantel, diethylcarbamazine.

Question 31

What is the indication and mechanism of action of niclosamide?

Answer 31

It is used to treat tapeworm infection by inhibiting glucose uptake, oxphos and anaerobic metabolism.

Question 32

What causes the proteinuria in nephrotic syndrome?

Answer 32

Podocyte damage leading to loss of the negative glomerular charge barrier.

Question 33

What is the mechanism of pindolol and acebutolol?

Answer 33

Partial beta agonist.

Question 34

What is the mechanism of action of aminoglycosides in gentamicin and streptomycin? What you need to watch out for?

Answer 34

Irreversibly inhibit initiation to the 30S subunit and stop translocation thereby blocking bacterial protein synthesis. Requires oxygen for uptake.

Nephrotoxicity, neuromuscular blockade and ototoxicity can occur. Teratogenic.

Question 35

What is the mechanism by which acetaminophen causes hepatotoxicity?

Answer 35

Cytochrome P 450 metabolism produces NAPQI -> depletion of glutathione stores.

Question 36

Describe how P450 activity changes with alcoholism

Answer 36

Acute alcohol abuse = decreased P450

chronic alcohol abuse = induction of P450.

Question 37

Describe the function of the bulbourethral glands and seminal vesicles.

Answer 37

Bulbourethral glands = lubrication added

Seminal vesicles = produce majority of seminal fluid.

Question 38

Differentiate between caseating, coagulation and fat necrosis?

Answer 38

Caseous -> granuloma e.g. TB and systemic fungi

Fat -> lipase breaks down triglyceride, saponification (blue on H&E)

Coagulative -> preserved cell arch, red/pink on H&E)

Question 39

Differentiate the effects of atrial natriuretic peptide and B type natriuretic peptide.

Answer 39

ANP -> atrial myocytes

BNP -> ventricular myocytes, longer half-life.

Both are secreted in response to tension’s an act via cGMP to cause vasodilation, decreased sodium resorption at the collecting tubule, dilation of the afferent arteriole and constriction of the efferent arteriole to promote diuresis.

Question 40

Describe the course of the internal thoracic artery.

Answer 40

Branches off the subclavian artery and descends vertically to supply the anterior chest wall and breast. Commonly used as a coronary artery bypass graft.

Question 41

What is the most important prognostic factor for breast neoplasm?

Answer 41

Degree of lymph node spread.

Question 42

What is the mechanism of acion of fluoroquinolones? What are the important contraindications?

Answer 42

Inhibits topoisomerase II and IV (DNA gyrase).

Can cause cartilage damage, so not used in pregnancy or children

Can cause tendonitis and tendon rupture in older adults.

Question 43

Describe the symptoms and inheritance of acute intermittent porphyria.

Answer 43

Due to a mutation autosomal dominant in porphobilinogen deaminase.

Precipitated by drugs, alcohol and starvation

Painful abdo

Port-wine colored pee

Polyneuropathy

Psychological disturbances.

Treat with hemin and glucose

Question 44

What are the mechanism of action of oseltamivir and zanamivir?

Answer 44

Inhibition of influenza neuraminidase resulting in decreased release of progeny virus.

Question 45

What does thromboxane A2 do?

Answer 45

It is produced by activated platelets and activates thromboxane receptor, which results in shape change and degranulation of platelets, recruitment of additional activated platelets and stabilization of the clot.

Question 46

A harsh systolic murmur over the tricuspid area in a young child is most likely due to what?

Answer 46

A ventricular septal defect

Question 47

A patient with diabetic ketoacidosis presents with the following black eschars on their face. What is the causative organism?

Answer 47

Mucormycosis (caused by mucor and rhizopus fungi, irregular broad nonseptate hyphae with WIDE angles)

Question 48

What is Gilbert syndrome?

Answer 48

Mild unconjugated bilirubinemia usually co-occurring with stress or illness. A common, benign and autosomal recessive condition.

Question 49

This electron micrograph shows a neuromuscular junction. Autoantibodies against the areas shown in arrows would be present in what disorder?

Answer 49

Lambert-eaton myasthenic syndrome (the arrows indicate presynaptic membranes with Ca2+ channels)

Question 50

Orthostatic hypotension in a patient who is taking acetazolamide for altitude sickness is most probably caused by?

Answer 50

Hypovolemia.

Question 51

Describe the cluster A personality disorders

Answer 51

Characterized by behavior which impairs meaningful social relationships:

Paranoid = Accusatory

Schizoid = Aloof (social withdrawal)

Schizotypal = Awkward (odd beliefs, eccentric)

NO association with schizophrenia.

Question 52

Differentiate between pulmonary embolism and pulmonary edema.

Answer 52

An embolism would present with VQ mismatch, sudden onset dyspnea, pleuritic chest pain, tachypnea, and tachycardia.

Edema = findings of consolidation, crackles, wheezes and ronchi.

Question 53

What is a myxoid tumor?

Answer 53

Most common cardiac tumor in adults presenting with a ball-valve obstruction. Myxoma cells immersed in glycosaminoglycans on histology

Question 54

How would ischemic colitis present?

Answer 54

At watershed areas including the splenic flexure and the rectosigmoid junction; may have bloody stools.

Question 55

What is the most likely diagnosis based on his bone marrow aspirate?

Answer 55

Multiple myeloma: lots of small round dysplastic cells. Clinically, look out for sudden-onset worsening back pain and B symptoms.

Question 56

A tumor is positive on immunohistochemistry or synaptophysin, chromogranin and neuron specific enolase. It is located next to the bifurcation of the carotid artery. What is the most likely tumor?

Answer 56

A paraganglioma (benign, but can become malignant). This particular tumor is neuroendocrine.

Question 57

What is the brain pathology shown here? What is the clinical presentation?

Answer 57

Normal pressure hydrocephalus, idiopathic, normally affects the elderly

Wet = urinary incontinence

Wobbly = gait adraxia

Wacky = cognitive dysfunction.

Question 58

What disorder is associated with this picture? What is the etiology? How is it treated?

Answer 58

Dermatitis herpetiformis.

Caused by IgA deposits at tips of dermal papillae and associated with celiac disease.

Treatment: dapsone, gluten-free diet.

Question 59

A microcytic anemia with spoon nails, glossitis, and cheilosis is most likely caused by?

Answer 59

Iron deficiency

Question 60

Absent HGPRT presents as what?

Answer 60

Lesch-Nyhan syndrome

Hyperuricemia

Gout

Pissed off (aggression and self-mutilation)

Retardation

DysTonia

treat with allopurinol.

Question 61

What diet would be most helpful to reduce diabetes risk in an overweight patient with no other lab abnormalities?

Answer 61

Low-caloric

Question 62

How should you counsel a 15yo male who presents with unilateral breast enlargement with a palpable bud who is otherwise developing normally?

Answer 62

This is normal and should eventually go away with time.

Question 63

What is the leading cause of death in women?

Answer 63

Cardiovascular disease

Question 64

What is the best way to reduce the spread of Klebsiella pneumoniae in hospital.

Answer 64

Hand hygiene

Question 65

What is the mechanism of the diphtheria exotoxin?

Answer 65

ADP ribosylation and inhibition of elongation factor 2.

Question 66

What is the preferred way to rapidly reverse warfarin?

Answer 66

Fresh frozen plasma

Question 67

How do you treat pulmonary hypertension in a newborn?

In an adult?

Answer 67

Neonate = Nitric oxide

PDE-5 inhibitors such as sildenafil

endothelin receptor antagonist including bosentan

Protacyclin analogs (epoprostenol, iloprost)

Question 68

What maintains the ATP concentration in skeletal muscle, cardiac muscle and brain?

Answer 68

Creatine phosphate.

Question 69

Why is Plasmodium vivax treated with both primaquine and chloroquine?

Answer 69

Primaquine kills hypnozoites (dormant form associated with relapse)

Question 70

What is lung elastic recoil?

Answer 70

The tendency for the lungs to collapse inward and for the chest wall to spring outward.

Question 71

Deficiencies of which micronutrients can cause delayed wound healing?

Answer 71

Delayed proliferative stage: vitamin C and copper

delayed remodelling: zinc

Question 72

How does the carotid sinus sense blood pressure?

Answer 72

A drop in arterial pressure leads to decrease stretch which in turn causes baroreceptor firing and increased sympathetic and decreased parasympathetic function

Question 73

Describe the derivatives of the four pharyngeal pouches

Answer 73

1. ear
2. tonsils
3. dorsal wings to the inferior parathyroids, ventral wings to the thymus.
4. dorsal wings to Superior parathyroids, ventral wings to ultimopharyngeal body and para-follicular cells of thyroid

Question 74

What is the finding in this barium swallow?

Answer 74

Protrusion of the fundus into the chest above the level of T10

Question 75

Describe how RANKL regulates osteoclasts.

Answer 75

RANKL is expressed on the surface of osteoblasts and stimulates osteoclasts

Question 76

Which enzymes are affected by lead poisoning?

Answer 76

Ferrochelatase and aminolevulinic acid dehydratase

Question 77

What is the storage and active form of vitamin D?

Answer 77

Storage: 25 – OH D3 in liver

Active: 1, 25-(OH)2 S3 (calcitriol) converted in kidney

Question 78

Describe the classification and clinical relevance of GAS (Streptococcus pyogenes)

Answer 78

Gram-positive cocci in chains which are beta-hemolytic and bactracin sensitive.

Causes pharyngitis, cellulitis, impetigo, erysipelas, scarlet fever, toxic shock like syndrome, necrotizing fasciitis, rheumatic fever, and glomerulonephritis

Question 79

Describe Pierre Robin sequence. Which pharyngeal arches are defective?

Answer 79

The sequence is micrognathia, glossoptosis, cleft palate, airway obstruction.

First pharyngeal arch (responsible for the maxillary and mandibular processes as well as the muscles of mastication)

second pharyngeal arch (responsible for cartilage of the stapes, styloid processes, lesser horn of the hyoid, stylohyoid ligament and the muscles of facial expression)

Question 80

Which properties of anaesthetics are responsible for rapid induction and recovery as well as potency?

Answer 80

Rapid induction: decreased solubility in blood

increased potency: increase solubility in lipid.

Question 81

What causes the closure of the foramen ovale and ductus arteriosus after birth?

Answer 81

With the first breath, pulmonary resistance drops leading to an increase in left atrial pressure, shutting foramen ovale.

As O2 increases and prostaglandins (from placental separation) decrease, the ductus arteriosus closes. Note that cyclooxygenase (resp. for prostaglandin synthesis) inhibition can also play a role.

Question 82

Where is vitamin B12 absorbed?

Answer 82

The terminal ileum: it requires intrinsic factor.

Question 83

Compare tetanus and botulism toxin.

Answer 83

Both proteases Cleves snare and stop neurotransmitter release. Tetanus results from inhibited release of inhibitory neurotransmitters whereas botulism results from inhibition of stimulatory neurotransmitters.

Question 84

Describe the role of IkB in regulating NF-kB singnalling

Answer 84

IkB is phosphorylated by IKK, leading to release of NF-kB

Question 85

What are the irreversible enzymes of gluconeogenesis?

Answer 85

Pyruvate carboxylase

Phosphoenolpyruvate carboxylase

Fructose 1,6 bisphosphatase

Glucose 6 phosphatase

Question 86

What is the Haldane effect?

Answer 86

Deoxygenated blood has a higher affinity for carbon dioxide than oxygenated blood. This is due to deoxyhemoglobin acting as a buffer for to pull H2CO3 -> HCO3- + H+

Question 87

A defect in which protein is associated with dextrocardia?

Answer 87

Dynein (Kartagener syndrome).

Question 88

What disturbance in serum pH is caused by loop diuretics and thiazides?

Answer 88

Metabolic alkylosis

Question 89

What is the neoplasm?

Answer 89

Medullary thyroid carcinoma, originating from parafollicular C cells (makes calcitonin).

Key characteristic is sheets of polygonal cells in amyloid stoma

Question 90

What is the effect of antibiotics on fecal excretion for salmonella and Shigella?

Answer 90

Salmonella treatment results in longer excretion

Shigella treatment results in shorter excretion

Question 91

Which coronary artery supplies the posterior left ventricle?

Answer 91

The right coronary artery

Question 92

What does the diphtheria vaccine contain?

Answer 92

Purified inactivated diphtheria toxin

Question 93

Which germ cell layer does the esophagus come from?

Answer 93

The endoderm

Question 94

Describe the first four weeks of fetal development

Answer 94

1. Blastocyst implantation at day six, hCG secretion from embryo begins.
2. Bilaminar disk (2 layers)
3. Gastrulation (3 layers), formation of neural plate
4. Neurlation, limb buds (4 limbs), heart begins to beat.

Question 95

Name some distinguishing characteristics for Streptococcus and Staphylococcus.

Answer 95

Gram +ve (both)

Streptococcus is in chains, Staphylococcus is in clusters

Streptococcus is alpha or beta-hemolytic, Staphylococcus is catalase positive

Question 96

What are the characteristics and members of viridans group streptococci?

Answer 96

Gram-positive, alpha hemolytic cocci which are opthrochin resistant and bile insoluble.

S mutans and S mitis -> dental carries

S sanguinis bind fibrin-platlet aggregates on damaged heart valves.

Question 97

Name some examples of the 4 major classes of HIV therapeutics.

Answer 97

1. (non)Nucleotide reverse-transcriptase inhibitors: abacavir, didanosine, emtricitabine, lamivudine, stavudine, tenofovir, zidovudine | delavirdine, efavirenz, nevirapine
2. Integrase inhibitors: bitegravir, dulotegravir, elvitegravir, raltegravir
3. Protease inhibitors: Atazanavir, Darunavir, fosamprenavir, indinavir, lopinavir, ritonavir, saquinavir
4. Entry inhibitors: Enfuvirtide (inhibits fusion) and Maraviroc (inhibits docking).

Question 98

Name the four classes of obligate anaerobes

Answer 98

Clostridium, Bacteroides, Fusobacterium, Actinomyces

(can’t breathe fresh air)

Question 99

Is Bacillus subtilis pathogenic?

Answer 99

no

Question 100

What is the lymphatic drainage from the cervix?

Answer 100

Internal iliac

Question 101

What is the blood supply to the AV node and diaphragmatic surface of the heart?

Answer 101

the posterior interventricular artery, a branch of the circumflex artery.

Question 102

What are the enzymes involved in acute intermittent porphyria and porphyria cutanea tarda?

Answer 102

porphobilinogen deaminase and uroporphyrinogen decarboxylase

Question 103

Staphylococcal toxic shock syndrome: how do they hint it, what will you find on labs?

Answer 103

Hints: nasal packing or tampon use,

Increased AST, ALT and bilirubin, fever, rash & desquamation

shock & end-organ failure.

Question 104

What is the innervation of the gut?

Answer 104

Vagus nerve from pharynx to 2/3 transverse colon

Pelvic nerve from distal 1/3 colon to upper anal canal.

Question 105

What are the classic findings for pheochromocytoma?

Answer 105

increased catecholamines and metanephrines (homovanillic acid, vanillylmandelic acid) in urine and plasma.

Question 106

What pathologic process resulted in this kidney?

Answer 106

Hydronephrosis (notice widening fo the calices)

Question 107

What would be the cause of elevated parathyroid hormone in the setting of low calcium levels?

Answer 107

Rickets or osteomalacia (also high ALP and low PO4)

Question 108

How do you distinguish between primary and secondary hyperparathyroidism?

Answer 108

Primary = HIGH Ca2+, low phosphate

secondary (often compensatory for CKD = low vitamin D) = low CA2+ and high PO4

Question 109

What is the acronym for findings in systemic lupus erythematosus?

Answer 109

RASH OR PAIN

Rash (malar, discoid)

Arthritis

Serotitis (pleuritis, pericarditis)

Hematologic disorder (cytopenias)

Oral or nasopharyngeal ulcers

Photosensitivity

Antinuclear antibodies

Immunologic disorder (anti dsDNA, anti-sm, antiphospholipid)

Neurologic disorder (seizure, psychosis)

Question 110

What is gardner syndrome?

Answer 110

Familial adenomatous polyposis + osseous and soft tissue tumors + congenital hypertrophy of retinal pigment epi + impacted or supernumerary teeth.

Question 111

What is conversion disorder?

Answer 111

Functional neurologic symptom disorder: acute motor or sensory LOF following a stressor, typically patient is aware but may not be bothered by the symptoms.

Question 112

What is the most effective way to screen fresh frozen tissue and paraffin-embedded specimens for presence of a particular protein?

Answer 112

immunohistochemistry

Question 113

Differentiate between cluster B personality disorders

Answer 113

Bad (antisocial = sociopath)

Borderline (unstable personal and interpersonal relationships, emotional emptiness, splitting)

flambuoyant (histrionic = attention-seeking, dramatic, shallow, labile emotions)

Best (narcissitic = gradiosity and sense of entitlement, lack of empathy)

Question 114

What are the symptoms of croup? What is the causative virus?

Answer 114

Croup aka acute laryngotracheobronchitis. Barking cough and inspiratory stridor.

Caused by parainfluenza virus.

Question 115

Individuals with sickle cell disease are more susceptible to bacteremia caused by which organism?

Answer 115

Salmonella: can present with osteomyelitis, liver/spleen abcess, sepsis.

Question 116

Which population is at increased risk for sarcoidosis?

Answer 116

African-american (females)

Question 117

What disease is associated with this finding on biopsy? What are the other associated symptoms on CXR and PE?

Answer 117

Noncaseating granuloma = sarcoidosis

Presents with bilateral adenopathy and coarse reticular opacities.

Other associated symptoms: bell’s palsy, uveitis, lupus pernio (lupus-like skin lesions), interstitial fibrosis, erythema nodosum, RA-like arthropathy, hypercalcemia.

Treat with steroids.

Question 118

What is a Tc-99 scan used for?

Answer 118

Uptake indicates active thyroid (Tc-99 is similar to the iodide ion). Tc-99 is not turned into thyroid hormone so better for dosimetry / children.

Question 119

Compare tissue from complete vs partial hydratiform mole.

Answer 119

Complete = hydropic villi, circumferential / diffuse trophoblast

Partial = fetal parts, some villi are hydropic + focal trophoblastic proliferation.

Question 120

What cranial nerve is affected by a posterior communicating artery aneurysm?

Answer 120

CN III (ipsilateral)

Question 121

How does serum insulin change in type II diabetes?

Answer 121

Initially increased, then decreases in advanced disease.

Question 122

Describe the causes and findings of the 4 types of shock

Answer 122

Hypovolemic (cold, clammy) due to hemorrhage, severe dehydration, burns) very low preload, increased systemic resistance)

Cardiogenic or obstrcutive (cold, clammy) due to MI, HF, valve dysfunction, arrythmia, tamponade, PE, or tension pneumo, very low cardiac output, increased systemic resistance)

Distributive shock due to sepsis or anaphylaxis (warm, increased CO, very low SR) or CNS injury (dry, low CO, very low SR).

Question 123

Distinguish between schizoid and schizotypal personality disorder.

Answer 123

Schizoid = voluntary social withdrawal, content with isolation

Schizotypal = odd beliefs or magical thinking, eccentric, interpersonal awkwardness.

Question 124

What medication would you give to someone who develops post-op urinary retention? What is its mechanism of action?

Answer 124

Bethanechol (can also be used for bowel ileus). A cholinomimetic, it increases phosphoinositide turnover in muscle cells of the bladder fundus.

Question 125

Distinguish between the MoA of tetracyclines and macrolides.

Answer 125

Tetracycline, doxycycline and minocystine bind the 30S subunit of bacterial ribosomes and prevent tRNA attachment.

Azithromycin, clarithromycin, erythromycin, binds 23S rRNA of the 50S ribosomal subunit blocking translocation.

Question 126

What is the most appropriate treatment for trichomonas vaginitis?

Answer 126

Oral metronidazole

Question 127

What is neostigmine used for?

Answer 127

it is an acetylcholinesterase inhibitor which does not penetrate the CNS (postop and neuorgenic ileus, urinary retention, myasthenia gravis and reversal of NMJ blockade post-op).

Question 128

A man presents with dyspnea and a chemical exposure and smells of almonds. What is the treatment?

Answer 128

Cyanide poisoning

1. Give nitrites to make cyanomethemoglobin (less toxic)
2. Give sodium thiosulfate to increase conversion to thiocyanate and renal excretion.

Question 129

When treating organophosphate poisoning, which drugs treats muscarinic vs nicotinic effects?

Answer 129

Atropine for DUMBBELSS symptoms (muscarinic)

Pralidoxime for neuromuscular blockade. (nicotinic)

Question 130

How do you calculate specificity?

Answer 130

True negative rate = TN/(all N) = TN/(TN + FP)

Question 131

How do you calculate sensitivity?

Answer 131

TP rate = TP / aii P = TP / TP + FN

Question 132

Distinguish between type I and type II errors in hypothesis testing.

Answer 132

Type I = falsely rejecting the null hypothesis, calculated by alpha or significance level

Type II = failing to reject the null = beta (power = 1-beta)

Question 133

Why is it important to pay attention to when a stem tells you a patient has had a condition “since birth”.

Answer 133

It implies a hereditary condition which is less likely to have an environmental component, e.g. for anemia, it suggests something like hereditary elliptocytosis or pyruvate kinase deficiency as opposed to sickle cell anemia or G6PD

Question 134

What is the immediate precursor and enzyme which produces norepinephrine?

Answer 134

precursor is dopamine

enzyme is dopamine hydroxylase

Question 135

Stick out your tongue and say “aaah” to test which cranial nerve?

Answer 135

Uvula elevation; cranial nerve X (vagus)

Question 136

Which conditions result in schistocytes on blood smear?

Answer 136

microangiopathic hemolytic anemias: DIC, TTP/HUS, HELLP syndrome

Question 137

Which cytokines mediate sepsis?

Answer 137

IL-1, IL-6, and TNF-alpha

Question 138

What is the mechanism of action of cyclosporine? What is the dose-limiting toxicity?

Answer 138

It is a calcineurin inhibitor which blocks T-cell activation by preventing transcription of IL-2. Nephrotoxic, neurotoxic, gingival hyperplasia, hirsutism

Question 139

Distinguish between causes of autoimmune hemolytic anemia.

Answer 139

Warm AIHA due to IgG, associated with SLE, CLL, alpha-methyldopa

Cold AIHA due to IgM, causes agglutination when exposed to cold, associated with Mycoplasma pneumoniae, infectious mononucleosis, CLL

Question 140

Besides the liver, which other organ is capable of sufficient gluconeogenesis to release glucose into circulation?

Answer 140

the kidney

Question 141

Describe the embryonal origin of the pituitary gland.

Answer 141

Anterior pituitary from oral ectoderm (rathke pouch)

Posterior pituitary from neurectoderm

Question 142

Which cytokine is involved in recruiting neutrophils to the site of an infection?

Answer 142

IL-8

Clean-up on aisle 8

Question 143

What is the significance of the kappa:lambda ratio?

Answer 143

Kappa:lambda higher than 3 is indicative of monoclonal lymphoma (or other lymphoproliferative disease)

Question 144

What are the lung findings characteristic of idiopathic pulmonary fibrosis?

Answer 144

Increased collagen deposition, honeycomb appearance on CT, traction bronchiectasis (higher FEV1 than expected)

Question 145

Which pathway is affected by warfarin? What is the first factor to be depleted?

Answer 145

The extrinsic pathway (measured by PT), Factor VII

Question 146

How would you describe the lesion? What is it called? What is the causative organism?

Answer 146

umbilicated papulees ; molluscum contagiosum

poxvirus

Question 147

What is the autoimmune target in myasthenia gravis? Which cancer is associated with it?

Answer 147

Post-synaptic ACh receptors at the neuromuscular junction; thymoma

Question 148

What is the course of the inferior alveolar nerve?

Answer 148

It is a branch of the mandibular nerve which runs through the mandibular canal to supply sensation to the lower teeth. It exits at the mental foramen

Question 149

What mutations cause familial hypercholesterolemia?

Answer 149

Absence of the LDL receptor on hepatocytes.

Question 150

What is the mechanism of action of capsofungin? What are the other drugs in it sclass

Answer 150

Inhibits synthesis of beta-glucan, blocks cell wall synthesis. Useful for Candida and aspergillosis

Also micafungin and anidulafungin

Question 151

What do lesions of the subthalamic nucleus produce?

Answer 151

Contralateral hemibalismus

Question 152

What is the mechanism of action of reperfusion injury in cardiac ischemia?

Answer 152

Generation of mitochondrial free radicals and membrane lipid peroxidation

Question 153

What does this X-ray indicate

Answer 153

Congential diaphragmatic hernia (note the placement of the NG tube, the absence of bowel gas and the right-shift of the mediastinum)

Question 154

What are the classic signs/symptoms associated with inhalant abuse (e.g. sniffing glue).

Answer 154

Peaks around 8th grade. Headaches, N/V, belligerence, drowsiness, lethargy, poor school performance.

Long-term effects include ataxia, brain damage possible.

Question 155

Label the nerves

Answer 155

A- CN III oculomotor

B - CN IV trochlear

C - CN VI abducent

D - CN V1 trigeminal/opthalmic

E - CN V2 trigeminal/maxillary

Question 156

Which pituitary hormone is responsible for stimulating testosterone production?

Answer 156

LH

Question 157

What mediates the inflammation seen in crohn’s disease?

Answer 157

T-lymphocytes

Question 158

Acute kidney injury in an endurance athlete should raise suspicion for what condition? What is the protein that builds up?

Answer 158

Rhabdomyolysis - myoglobin

Question 159

Nosocomial infection by gram-positive, catalase-negative cocci in pairs/chains is most likely which organism?

Answer 159

enterococcus faecalis (think VRE).

Question 160

What protein structure produces characteristic birefringent pattern when stained with congo red?

Answer 160

Amyloid beta pleated sheets.

Question 161

What is the arterial supply for the uterus?

Answer 161

The internal iliac artery

Question 162

In a patient with sarcoidosis, what serum concentrations will be elevated?

Answer 162

1,25-dihydroxycholecalciferol (activation in macrophages) leading to elevated calcium levels

Question 163

What does normal/low BP in the context of an elevated JVP indicate?

Answer 163

Right-sided heart failure (hence, increased cap hydrostatic pressure)

Question 164

Describe this cardiac lesion

Answer 164

Myxoma

Question 165

What vaive pathology results in concentric LV hypertrophy?

Answer 165

Aortic stenosis

Question 166

What disease is caused by Trypanosoma brucei?

Answer 166

African sleeping sickness (enlarged lymph nodes, recurrent fever, somnolence, coma) spread by the Tsetse fly.

Question 167

What immune deficiency would lead to susceptibility to Neisseria bacteremia?

Answer 167

Terminal complement deficiency (C5-C9)

Question 168

To confirm hyperthyroidism, what should you measure?

Answer 168

Free T3 and/or T4 (bound T3/T4 is inactive, so total T3 is not useful)

Question 169

What is the trousseau sign? What condition is associated with it?

Answer 169

Hypoparathyroidism -> occlusion of brachial artery with BP cuff leads to carpal spasm

Question 170

How do you distinguish between eosinophilic granulomatosis with polyangiitis (Churg-Strauss) and granulomatosis with polyangiitis (Wegener)?

Answer 170

Churg-Strauss: asthma, sinusitis, skin nodules, peripheral neuropathy which may have heart/GI and kidney involvement; key marker is perinuclear(MPO)-ANCA

Wegener: resp necrotizing granulomas in nasal septum, sinusitis, otitis media, mastoiditis, hemoptysis cough and dyspnea with necrotizing glomerulonephritis and focal necrotizing vasculitis. Key marker is serum antineutrophil cytoplasmic antibody (c-ANCA or PR3-ANCA)

Question 171

How are burns classified (degrees)

Answer 171

1. Superficial (epidermis only, sunburn
2. All epidermis + some dermis; blisters
3. Full thickness of dermis, white waxy and leathry, does not blanch, painless
4. Through to deeper tissue eg muscle and bone, no feeling in area, nerve endings destroyed.

Question 172

What is the mechanism of action of ezetimibe?

Answer 172

Prevents cholesterol absorption in small intestine (brush border)

Question 173

Which diuretic is good for hepatic ascities and HF?

Answer 173

Spironolactone

Question 174

What causes gynecomastia in men?

Answer 174

Increases in sex hormone binding globulin (either due to estrogen or chronic liver disease, or drugs) reduces circulating levels of free testosterone.

Question 175

What is the first-line pharmacotherapy for OCD?

Answer 175

SSRI or SNRI

Question 176

What are the second-generation histamine-1 blockers? What’s their advantage over the first gen?

Answer 176

Loratadine, fexofenadine, desloratadine, cetirizine. Less sedation due to lower CNS entry

Question 177

What are the drugs which can induce long-QT and put patients at risk of Torsades de pointes? What are other risk factors? How do you treat?

Answer 177

Antiarrhythmics (specifically IA and III)

Antibiotics (macrolides)

Anti”C“ychotics (haoperidol)

Antidepressants (TCAs)

Antiemetics (odansetron)

Hypo K+, Ca++ or Mg++

Treatment is magnesium sulfate.

Question 178

What is sulfsalazine used for?

Answer 178

Combo sulfapyridine (antibacterial) and 5-aminosalicylic acid (anti-inflammatory) for UC and Crohn disease (colitis).

Question 179

Which vaccines will stimulate both cellular and humoral responses?

Answer 179

(Attention, Teachers! Please Vaccinate Small Beautiful Young Infants with MMR Regularly)

Adenovirus (nonattenuated), Typhoid, Polio, Varicella, BCG, Yellow fever, Influenza (intranasal), MMR, Rotavirus.

Question 180

Distinguish between the aminoglycosides and the macrolides

Answer 180

Aminoglycosides (Gentamicin, Neo, Amikacin, Tobra, Strepto) bind 30S subunit, require O2 for uptake. Bactericidal and used for gram -ve rod infections

Macrolides bind 50S subunit (23S rRNA), used for atypical pneumonis, gram +ve cocci infections and B pertussis.

Question 181

How do you calculate odds ratio for an exposure?

Answer 181

(Odds of exposure in those with disease) / (odds of exposure with no disease)

i.e. [(E+ D+) / (E- D+)] / [(E+ D-) / (E- D-)]

Question 182

What are the nonselective alpha and beta antagonists?

Answer 182

Labetalol and carvedilol

Question 183

What is the mechanism of action of hydralazine? What is it used for?

Answer 183

It increases cGMP and results in vasodilation of arterioles > veins, reducing afterload.

Question 184

How does SIADH affect electrolyte concentrations?

Answer 184

Euvolemic hyponatremia (due to continued excretion of Na+)

Question 185

What is renal papillary necrosis? What are its causes?

Answer 185

Gross hematuria and proteinuria due to sloughing off of necrotic renal papillae. Associated with sickle-cell disease or trait, acute pyelonephritis, analgesics (NSAIDs), diabetes mellitus. (SAAD papa)

Question 186

What characteristic causes E. coli to stain gram-negative?

Answer 186

it has a thin peptidoglycan layer and an outer membrane.

Question 187

What causes a horseshoe kidney? Why would a horseshoe kidney complicate abdominal surgery?

Answer 187

Horseshoe kidneys occur when the interior poles of both kidneys fuse and get trapped under the IMA. As a result, although the course of the ureters remains normal, the blood supply for the kidneys is abnormal.

Question 188

What immune response causes induration at the site of a bee sting?

Answer 188

Macrophages which produce IL-1, IL-6, and TNF alpha.

Question 189

What alternative testing methodolgy for TB produces fewer false positives from BCG vaccination?

Answer 189

The interferon-gamma release assay (whole blood is incubated with synthetic peptides).

Question 190

What cellular mechanism may help explain muscle atrophy?

Answer 190

Polyubiquitination and degradation of proteins

Question 191

If you were to do BAL on an aspiration pneumonia what bacteria might you expect to find?

Answer 191

Normal oral flora

Question 192

Distinguish between the three protozoa which cause gastrointestinal infections.

Answer 192

Giardia is associated with multi-nucleated trophozoites and foul-smelling fatty diarrhea.

Entamoeba histolytica is associated with bloody diarrhea, liver abscess and trophozoites which consume RBCs.

Cryptosporidium is associated with severe diarrhea and aids or mild disease immunocompetent hosts (watery diarrhea).

Question 193

What is leukoplakia?

Answer 193

White patches or spots on the inside of the mouth. Associated with chewing tobacco, heavy smoking, and alcohol use and may progress to squamous cell carcinoma.

Oral Harry leukoplakia occurs in immunocompromised to do EBV where the patches have folds.

Question 194

What is a leukemoid reaction?

Answer 194

Increase in WBCs which mimic leukemia due to infection / another disease, which returns to normal following resolution of the condition.

Question 195

Differentiate between precontemplation and contemplation.

Answer 195

Precontemplation involves denial of the problem whereas contemplation acknowledges the problem but is unwilling to change.

Question 196

How would you characterize the pulmonary zone which is occluded due to a large embolism?

Answer 196

Dead space

Question 197

What is the embryological origin of the aorticopulmonary septum?

Answer 197

Neural crest cells

Question 198

What structures or cells originate from the neural crest cells?

Answer 198

MOETL PASSES

Melanocytes, Odontoblasts, Tracheal cartilage, Enterochromaffin cells, Leptomininges (arachnoid + pia), PNS ganglia, Adrenal medulla, Schwann cells, Spiral (aorticopulmonary) membrane, Endocaridal cushions (partial), Skull bones.

Question 199

What types of inhibitor binding cannot be overcome by simply increasing the concentration of agonist?

Answer 199

Either noncompetitive antagonism or partial agonism.

Question 200

What reaction does an ACE inhibitor target?

Answer 200

The conversion of angiotensin I to angiotensin II.

Question 201

What organism causes these lesions? What is the pattern of spread? What exposures are more likely to result in this disease?

Answer 201

Sporotrichosis (Sporothrix schenckii) a cigar shaped yeast which lives on vegetation (“rose gardner’s disease”) and causes ascending lymphangeitis.

Question 202

What are the characteristics of Pseudomonas aeruginosa?

Answer 202

It is a gram-negative rod that is aerobic, catalase and oxidase -positive and non-lactose fermenting. Colonies produce green colour and grape-like odour.

Question 203

Name the numbered parts of the spinal cord

Answer 203

1. Skin
2. Fascia/fat
3. Supraspinous ligament
4. Interspinous ligament
5. Ligamentum flavum
6. Epidural space
7. Dura mater
8. Arachnoid mater
9. Subarachnoid space

Question 204

What are the functions of the 5’ cap on mRNA?

Answer 204

1. Nuclear export (cap binding complex)
2. preventing degradation
3. promoting translation (recognized by eIF4F)
4. 5’ proximal intron excision

Question 205

Describe the foramina through which the divisions of the trigeminal nerve pass?

Answer 205

V1 Superior orbital fissure

V2 foramen rotundum

V3 Foramen ovale

Question 206

What is heteroplasmy?

Answer 206

both normal and mutated mtDNA present, variable expression of mitochondrially inherited disease.

Question 207

Describe the signs and symptoms of vitamin E deficiency

Answer 207

Hemolytic anemia, acanthocytosis (spur cells), muscle weakness, demyelination of posterior columns (loss of position and vibration sense) and spinocerebellar tract (ataxia)

Question 208

3 hormones of appetite regulation? What are they, what do they do?

Answer 208

Ghrelin is the hunger hormone

Leptin is the satiety hormone

Endocannabinoids increase appetite (munchies)

Question 209

How does smoking affect the lung?

Answer 209

Increases mucus production and secretion, decreases activity of airway cillia and alveolar macrophages.

Question 210

Which parts of the kidney will experience ischemic injury first?

Answer 210

The straight segment of the proximal tubule and the thick ascending limb

Question 211

Describe the pathophysiology of albinism

Answer 211

Normal melanocyte numbers but unable to produce melanin or decreased melanin production due to defects in tyrosine transport or tyrosinase.

Question 212

When trying to find the primary site for a metastasis, what should you consider?

Answer 212

Make sure you are able to explain all of this physiologic symptoms based on the primary site of the tumor.

Question 213

What is the defective protein in Marfan syndrome.

Answer 213

FBN1 gene mutation results in defective fibrillar which normally forms a sheath around elastin.

Question 214

What is pseudofolliculitis barbae?

Answer 214

Most commonly occurs as razor bumps on African-American males which are hyper pigmented papules and pustules that are painful and pruritic on the cheeks, jawline and neck.

Question 215

What is the presentation of SMA stenosis?

Answer 215

Severe postprandial abdominal pain (due to ischemia) and weight loss, typically with atherosclerotic disease elsewhere.

Question 216

How does niacin lower cholesterol levels?

Answer 216

It decreases VLDL and raises HDL by inhibiting lipolysis and reducing hepatic VLDL synthesis

Question 217

What is the mechanism of resistance in VRE?

Answer 217

Substitution of lactate for alanine in D-ala-D-ala cell wall precursors.

Question 218

What complications of MI can occur acutely within the first week and result in murmurs?

Answer 218

Papillary muscle rupture leading to severe mitral regurgitation (apex holosystolic murmur)

interventricular septal defect (VSD—LLSB holosystolic murmur)

Question 219

What is Fanconi syndrome?

Answer 219

Generalized reabsorption defect of the proximal convoluted tubule often associated with hereditary defects, ischemia, multiple myeloma, or nephrotoxins.

Question 220

What malaria-causing protozoans require primaquine to prevent relapse?

Answer 220

P. vivax & P. ovale (due to hypnozoite)

Question 221

What does endothelin-1 do in the lung? What drugs target it?

Answer 221

Increases pulmonary vascular resistance

Bosentran (antagonizes endothelin-1 receptors)

Question 222

How is kallikrein related to the clotting cascade?

Answer 222

It is activated by factor XII and increases the conversion of plasminogen into plasmin.

Question 223

How does a fatty-acid chain acyl-CoA dehydrogenase deficiency present?

Answer 223

hypoketotic hypoglycemia (can cause sudden death in infants/children)

Question 224

Where is the lateral corticospinal tract? Where do neurons from here synapse?

Answer 224

E/F

first synapses on the anterior horn from which the LMN’s the spinal cord.

Question 225

Describe the pathophysiology of asthma. What histological features are associated?

Answer 225

Cox inhibition leads to leukotriene overproduction and airway constriction, chronic sinusitis.

Smooth muscle hypertrophy and hyperplasia, Curschmann spirals and Charcot-leyden crystals.

Question 226

What is the relationship of Enkephalin and substance P to pain?

Answer 226

Enkephalin activates Delta opioid and mu opioid receptors.

Substance P is important for transduction of pain to the CNS.

Question 227

Calretinin and cytokeratin 5/6 are found in what type of neoplasm?

Answer 227

Mesothelioma

Question 228

What are the five Ps that are associated with acute interstitial nephritis?

Answer 228

Pee (diuretics)

Pain-free (NSAIDs)

Penicillins / cephalosporins

PPI

Rifampin

Sulfa drugs

Question 229

What is the classic presentation of kidney stones? What complications can be associated?

Answer 229

Unilateral flanked tenderness with sharp colicky pain radiating to groin and hematuria.

Complications include hydronephrosis pyelonephritis and AKI.

Question 230

What are the risk factors for gout?

Answer 230

Hyperuricemia (#1), male, HTN, obesity, DM, dyslipidemia, alcohol use

Question 231

What characteristics distinguish a hairy cell leukemia?

Answer 231

Stains tartarate resistant acid-phosphatase, LM shows hair-like projections on mature B cells. Pts typically have splenomegaly and pancytopenia. BRAF mutations

Question 232

What aneurysm is associated with an ipsilateral CN III palsy?

Answer 232

A posterior communicating artery aneurysm

Question 233

Which H2 blocker has the most drug interactionsD? What is the mechanism?

Answer 233

Cimetidine is a potent cytochrome P450 inhibitor.

Question 234

What is this organism? What symptoms does it cause? What is the appropriate treatment?

Answer 234

Schistosoma mansoni causes liver/spleen enlargement, fibrosis, inflammation & portal hypertension.

Treat with praziquantel

Question 235

When are PDE-5 inhibitors contraindicated?

Answer 235

When someone is taking nitrates / nitroglycerin due to risk of severe hypotension

Question 236

When you’re asked why a medication is contraindicated, what do you need to think about?

Answer 236

Patient factors and also drug-drug interacitons

Question 237

When calculating incidence from the population, what is the denominator?

Answer 237

new cases in given period / number of people that do not have the disease

Question 238

When is buproprion contraindicated?

Answer 238

Contraindicated in pts with electrolyte disturbances (e.g. anorexia nervosa) due to increased risk of seizures

Question 239

When is haloperidol contraindicated?

Answer 239

In patients which are obtunded or patients with Parkinson’s

Question 240

What is the mechanism of action of lactulose for hepatic encephalopathy?

Answer 240

Lactulose is digested by bacteria to lactic acid + acetic acid. This protonates NH3 -> NH4+ which then causes the ammonium to stay in the colon.

Question 241

Describe the pathway through which the fat soluble vitamins are absorbed.

Answer 241

Lacteals drain to thoracic duct into L subclavian (into systemic circulation)

Question 242

What signs are suggestive of specific IgA deficiency?

Answer 242

Frequent pneumonia (more than 2x in 1 yr), anaphylactic reaction to blood transfusion.

Question 243

Which organisms are more people with selective IgA deficiency more susceptible to?

Answer 243

Giardiasis (and other GI infections),

Question 244

What is rabbit antithymocyte globulin used for? What side effects can occur?

Answer 244

Used to prevent transplant rejection or aplastic anemia.

Can cause cytokine syndrome (type III hypersensitivitY)

Question 245

What does CD28 do? Which cells express it?

Answer 245

Binds MHCII / B7 for antigen presenting cells. Found on T cells.

Question 246

What does CD80/CD86 do? Which cell type is it found on?

Answer 246

It is another name for MHC II, B7 (antigen presentation) by macrophages.

Question 247

What is an open-label trial?

Answer 247

No blinding of researchers or participants. Does not preclude control or randomization.

Question 248

What characterizes a sertoli-leydig cell tumor?

Answer 248

Ovarian benign tumor which resembles testicular histology and may produce androgens

Question 249

What is a granulosa cell tumor?

Answer 249

Malignant sex cord stromal tumor which consists of call-exner bodies and often produces estrogen/progesterone. Presents with postmenopausal bleeding, endometrial hyperplasia, precocity (adolecents) and breast tenderness.

Question 250

What is the diagnosis? What is the most likely causative organism?

Answer 250

Folliculitis, may be pseudomonas aeruginosa.

Question 251

What is the mechanism by which H. pylori contributes to ulcer formation?

Answer 251

Elaboration of proteases and urease + local tissue destruction

Question 252

What genuses of bacteria are spirochetes?

Answer 252

Spirocheta, Treponema, Borrelia, Leptospira

Question 253

Differentiate between pemphigus vulgaris and bullous pemphigoid

Answer 253

Both type II hypersensitivity

Pemphigus vulgaris - possibly fatal, due to autoantibodies against desmoglein-1 (desmosomes -> connect keratinocytes in stratum spinosum). Presents with flaccid blisters, +ve nikolsky

Bullous pemphigoid - less severe, due to autoantibodies against hemidesmosomes (basement membrane). Presents with tense blisters, -ve nikolsky

Question 254

What happens to pneumocytes in interstitial pneumonitis?

Answer 254

Type 1 decreases, type II increases

Question 255

What is the most specific sign on physical exam of pulmonary arterial hypertension?

Answer 255

P2 (the S2 sound made by closure of the pulmonic valve) lounder than A2.(sound of aortic valves closing)

Question 256

Does a polymorphism need to cause a change in protein sequence to have clinical importance?

Answer 256

No; in fact any change in an allele’s DNA sequence qualifies.

Question 257

What is the best thing to say to someone who is frustrated by long wait time?

Answer 257

Apologize, thank them for waiting, offer to help.

Question 258

How do the baroreceptors, systemic/pulmonary vascular resistance and capillary fluid transfer change in an acute bleed?

Answer 258

Baroreceptor firing decreases, systemic & pulmonary resistance increases, and capillaries absorb fluid from the interstial space.

Question 259

Differentiate between anterior and posterior urethral injury

Answer 259

Anterior due to a straddle injury affecting spongy urethra, blood accumulates in scrotum, Buck fascia tear leads to blood in urethral space.

Posterior due to pelvic fracture affecting membranous urethra with urine leaking into retropubic space, high riding “boggy” prostate.

Suspect if blood at urethral meatus.

Question 260

What is the function of C3b?

Answer 260

opsonization

Question 261

Which complement factors are elevated in anaphylaxis?

Answer 261

C3a, C4a and C5a

Question 262

Which complement causes neutrophil chemotaxis?

Answer 262

C5a

Question 263

What is C5b-9?

Answer 263

The membrane attack complex (MAC) which defends against gram -ve bacteria, formed by activation of C5b under influence of C6-C9

Question 264

What are the common inducers of cyt-P450?

Answer 264

Modafinil, chronic alcohol use, St john wort, Phenytoin, Phenobarbital, Nevirapine, Rifampin, Griseofulvin, Carbamazepine

(most chronic alcoholics steal phen-phen and never refuse greasy carbs)

Question 265

What is the lymphatic drainage above and below the pectinate line?

Answer 265

Above: internal iliac

Below: superficial inguinal

Question 266

What cranial nerve may be disrupted by an orbital floor fracture?

Answer 266

The maxillary nerve (CN V)

Question 267

What is the effect of ACE inhibitors in pregnancy?

Answer 267

oligohydramnios, renal failure and hypocalvaria.

Question 268

Describe the histology from this specimen of colon. What is the diagnosis?

Answer 268

Noncaseating granuloima; crohn disease

Question 269

Brown blood and cyanosis is pathognomonic for what condition?

Answer 269

Methemoglobinemia; oxidized form of Hb (Fe3+). Caused by nitrites and benzocaine poisoning.

Question 270

How would you differentiate between a GBS and a GAS infection?

Answer 270

GAS is bacitracin sensitive, GBS is bacitracin resistant.

GBS is for babies! (pneumonia, meningitis, sepsis)

GAS causes pyogenic infections (strep throat, cellulitis, impetigo, erysipelas), toxigenic (scarlet fever, toxic shock, necrotizing fasciitis), immunologic (rheumatic fever, PSGN) infections.

Question 271

What is the mechanism of action of bisphosphonates?

Answer 271

Binds hydroxyapatite, inhibits osteoclasts.

Question 272

What is the virulence factor common to all paramyxoviruses?

Answer 272

Fusion protein (F) which causes fusion of respiratory epithelial cells

Question 273

Which tumor suppressors block the G1-S transition?

Answer 273

p16 (CDKN2A), Rb (via inhibition of E2F), and p53 (via p21)

Question 274

The following biopsy is taken from a child’s jaw lesion. What is the diagnosis? What is the process is occuring in the regions marked by arrows?

Answer 274

Burkitt lymphoma (starry sky with tingible body macrophages).

Question 275

What is the lymphatic drainage from the tongue?

Answer 275

Submental

Question 276

Differentiate between type I and type II errors in hypothesis testing?

Answer 276

Type I - false positive finding

Type II - false negative finding

Question 277

What is the presentation of tularensis? What is the treatment?

Answer 277

Varies; ulceroglandular is most common with lymphadenopathy + ulcer.

streptomycin or gentamicin

Question 278

What are the symptoms of Cushing syndrome?

Answer 278

CUSHINGS

High cholesterol

High urine cortisol

Skin changes (thin, striae)

Hypertension

Immunosuppression,

Neoplasms (can cause it)

Growth retardation (children)

High sugar

also amenorrhea and moon facies

Question 279

How does radon enter a home? What living situation may increase risk of radon exposure?

Answer 279

Via basement through drains, pipes, cracks and windows.

Question 280

Which enzyme is responsible for causing autodigestion of the pancreas?

Answer 280

Trypsin (pepsin is stomach)

Question 281

What innervation do the corticospinal tracts provide

Answer 281

Voluntary motor to ipsilateral alpha motor neuron

Question 282

What innervation do the spinothalamic tracts provide?

Answer 282

pain / temperature to the contralateral side of the body (cell bodies in dorsal root ganglion, 1st synapse is ipsilateral dorsal horn, which then cross over and ascend to VPL nucleus)

Question 283

What type of hypersensitivity reaction is eczema?

Answer 283

Type I (increased entry of antigens & microrganisms trigger immediate response)

Question 284

What are the GLP-1 analogs? What is their mechanism of action & side effect?

Answer 284

Liraglutide and exenatide (lower glucagon, increase glucose-dependent insulin release). N/V and pancreatitis, causes weight loss.

Question 285

What is the mechanism of action of canagliflozin / dapagliflozin or empagliflozin? What are the side-effects?

Answer 285

Blockade of SGLT2 leading to glucosuria / dehydration. UTI, candidiasis, dehydration, hyperK+, weight loss.

Question 286

What drugs work similarly to the GLP1 analogs?

Answer 286

DPP4 inhibitors (inhibits the enzyme that deactivates GLP1)

Linagliptin, saxagliptin, sitagliptin.

Question 287

Name the nerves A->E

Answer 287

A) axillary

B) median

C) ulnar

D) radial

E) suprascapular

Question 288

When a question suggests a particular nerve deficit to address via physical therapy, which muscles need to be strengthened?

Answer 288

Those which the nerve innervates.

Question 289

What is the presentation of ACA stroke?

Answer 289

Contralateral paralysis and sensory loss of the lower limb.

Urinary incontinence

Question 290

Which nerve is responsible for adducting the leg? What muscles are innervated?

Answer 290

Obdurator nerve innervates obdurator externus, adductor longus, adductor brevis, gracilis, pectineus and adductor magnus.

Question 291

What is the pathogenesis of Niemann-Pick disease?

Answer 291

Either mutations of lysozomal enzyme acid sphingomyelinase (type A or B) or mutations in NPC1 or 2 which result in defective lipid transport.

Question 292

Which cells are responsible for dividing to turn over intestinal epithelium?

Answer 292

Crypt cells

Question 293

What is a mechanism of action that differentiates tumor suppressor genes from oncogenes?

Answer 293

inhibition of cell cycle regulation

Question 294

Identify the area of the brain

Answer 294

Broca’s area

Question 295

What is 7-dehydrocholesterol?

Answer 295

It is converted via sun exposure to previtamin D

Question 296

What is the gene which makes dynein? What does dynein do?

Answer 296

Microtubule-associated ATPase (MAP-1C)

Retrograde transport.

Question 297

What change in the muscle microenvironment is indicative of muscle fatigue?

Answer 297

Lower pH

Question 298

What is the difference between a catabolite activator and an allosteric activator?

Answer 298

The catabolite activator protein binds cAMP and activates transcription of the lac operon.

Allosteric activator binds protein not at active site.

Question 299

What drugs are used for muscle paralysis in surgery or mechanical ventilation?

Answer 299

Succinylcholine (causes depolarization)

or Atracurium, cisatracurium, pancuronium, rocuronium, tubocurarine, vecuronium (competitive ACh antagonism)

Question 300

What structures does the 3rd pharyngeal pouch contribute to?

Answer 300

Thymus, left and right inferior parathyroids

Question 301

Identify the labeled structures

Answer 301

A - Deep dorsal vein

B - deep fascia

C - urethra

D - cavernous artery.

Question 302

How does parathyroid hormone increase calcium concentration?

Answer 302

Acts to increase 1,25-OH2-cholecalciferol synthesis, which then activates osteoclasts via paracrine stimulation of osteoblasts and increases Ca2+ and PO3 absorption in intestines.

Question 303

Where is the frontal lobe?

Answer 303

B

Question 304

What is the likelihood that 2 siblings have identical HLA type?

Answer 304

25% or 1/4

Question 305

Overflow incontinence is associated with what nerve damage?

Answer 305

Pelvic nerve (parasympathetic input to bladder)

Question 306

Differentiate between the clinical course of hep A/B/C/D/E

Answer 306

A - acute and self limiting in adults, asymptomatic in children

B - initial serum sickness progressive to carcinoma

C - slow progression to cirrhossis and carcinoma

D - like HBV

HEV - fulminant hepitatis is pregnant people.

Question 307

What is cardiac dominance?

Answer 307

Whether the posterior descending artery is supplied by the right coronary (85%) or left coronary (10%) or equally by both (5%)

Question 308

What is the mechanism of action of ACE inhibitors?

Answer 308

Decrease GFR by reducing angiotensin II, which normally acts to constrict efferent arterioles.

Prevents inactivation of bradykinin, which contributes to vasodilation

Question 309

Slimy stools and RUQ pain with large areas of destruction of intestinal epithelium is suspiscious for…

Answer 309

Amebiasis (caused by Entamoeba histolytica)

Question 310

Urethritis without cistitis and pyelonephritis and pyuria without other symptoms in urine suggests infection by what organism?

Answer 310

Chlamydia trachomatis.

Question 311

What is this lesion associated with?

Answer 311

Erythema multiforme, associated with M. pneumoniae, HSF, some drugs (sulfa, beta-lactams, phenytoin), with multiple types of lesions. Target lesion shown with epithelial disruption

Stevens johnson syndrome fever, bullae formation and sloughing of skin.

Question 312

What does the achilles tendon reflex test?

Answer 312

S1

Question 313

What is the key characteristic of membranous nephropathy

Answer 313

Thickening of glomerular basement membrane; granular deposits of IgG and C3

Question 314

What is the difference between basophilic strippling and ringed sideroblasts

Answer 314

Both present in sideroblastic anemia (lead poisoning, myelodysplastic syndromes, alcoholism), but can only see ringed sideroblasts under prussian blue stain.

Question 315

What is budd-chiari syndrome?

Answer 315

Thrombosis/compression of hepatic veins -> centrilobular congestion and necrosis; can cause “nutmeg liver”

Question 316

Which HIV therapeutics are associated with hyperglyciemia, GI intolerance and lipodystrophy?

Answer 316

Protease inhibitors (ends in navir)

Question 317

Which HIV therapeutics are associated with bone marrow suppression?

Answer 317

NRTIs

Question 318

What are the toxicities common to all non-nucleotide reverse transcriptase inhibitors?

Answer 318

Rash, hepatotoxicity.

Question 319

What are the causes of acute pericarditis?

Answer 319

Idiopathic / presumed viral

Cocksackie B

Neoplasia

Autoimmune (SLE; RA)

Uremia

Cardiovascular (acute STEMI, dressler syndorme)

Radiation

Question 320

Osteoblastic mets in bone is characteristic of what disease? Where are they most likely to be found?

Answer 320

Late-stage prostatic adenocarcinoma; likely found in spine (presents with back pain)

Question 321

What is the most reliable serum hormone marker to see that ovulation has occured?

Answer 321

Increase in progesterone

Question 322

What are key findings in Paget disease of bone? What is the treatment?

Answer 322

Isolated increase in ALP with local bone remodelling with thickening of cortex e.g. “picture frame vertebrae”, chalk-stick fractures of long bone, hearing loss (due to auditory foramen narrowing).

Treat with bisphosphonates

Question 323

What is meconium ileus? What is it associated with?

Answer 323

Obstruction of intestine due to meconium plug; associated with CF

Question 324

High retics + jaundice suggests what condition?

Answer 324

A hemolytic anemia

Question 325

Obliterative endarteritis is associated with what disease?

Answer 325

Syphilis

Question 326

What are the physiologic effects of the nonselective beta blockers? What are some examples?

Answer 326

Decreased CO (due to B1 blockade), Vasoconstriction (due to B2 blockade)

Nadolol, pindolol, propranolol, timolol

Question 327

In the treatment of prostate cancer, why is flutamide used alongside leuprolide?

Answer 327

Leuprolide = GnRH agonist, results in androgen increase initially. Flutamide is a competitive antagonist, blocks initial androgen surge.

Question 328

Which antibiotics are associated with photosensitivity?

Answer 328

Tetracycline, doxycycline and minocycline

Question 329

How do you differentiate carbon monoxide poisoning from cyanide poisoning? How does the therapy differ?

Answer 329

Carbon monoxide poisoining is typically associated with fires, car exhaust or gas heaters; cyanide with synthetic combustion or apricot seeds or cyanide ingestion.

Headache and dizziness, multiple family members involved, bilateral globus pallidus lesion

Treat with hyperbaric oxygen for CO, hydroxocobalamin followed by nitrites and sodium thioslulfate for CN.

Question 330

What defects lead to severe combined immunodeficiency? What are their mechanisms of inheritance?

Answer 330

Defective IL-2R gamma chain (X-linked recessive)

Adenosine deaminase deficiency (AR)

RAG mutation (VDJ recombination defect)

Question 331

How do you differentiate between obstructive and restrictive lung disease on PFTs?

Answer 331

Obstructive has increased lung volumes with decreased FEV1/FVC

Restrictive has decreased lung volumes and increased FEV1/FVC

Question 332

What is the difference between in situ cervical carcinoma and invasive cervical carcinoma?

Answer 332

The former stays above the basement membrane.

Question 333

How would you differentiate between postnasal drip and nocturnal asthma?

Answer 333

Wheezing and chest tightness is typically associated with asthma; allergy symptoms will more often present with PND

Question 334

What is the treatment for nocturnal asthma?

Answer 334

Inhaled corticosteroids

Question 335

With celiac disease, what is the expected change in phosphorus and calcitriol?

Answer 335

Secondary hyperparathyroidism resulting in hypocalcemia, hypophasphatemia and low vitamin D.

Question 336

How do you differentiate adhesive capsulitis vs subacromial bursitis?

Answer 336

Adhesive capsulitis = frozen shoulder

Subacromial bursitis specifically leading to impingement syndrome with painful arc 60-120deg or positive neer’s

Question 337

A virus which is destroyed by heating to 60deg has what characteristic?

Answer 337

Enveloped

Question 338

What markers characterize regulatory T cells?

Answer 338

CD3, CD4, CD5 and FOXP3

Question 339

What is the cause and presentation of IPEX?

Answer 339

Cause: genetic deficiency of FOXP3 leading to autoimmunity:

Immune dysregulation

Polyendocrinopathy

Enteropathy

X-linked + diabetes in male infants

Question 340

Where is the receptor for the signal recognition particle located?

Answer 340

the rough ER

Question 341

What substances are associated with swelling as a result of inflammation?

Answer 341

Leukotrienes (C/D/E-4) and histamine, serotonin

Question 342

What is the function of IgE? What does it bind?

Answer 342

Crosslinked when exposed to antigen and activates immendiate hypersensitivity >>histamine

Binds mast cells and basophils

Activates eosinophils with parasite infection

Question 343

Which electrolytes are lost due to stimulant laxative abuse?

Answer 343

Will cause hypokalemia

Can cause changes in chloride, bicarb, pH or sodium in either direction.

Question 344

What is the arterial supply to the pancreas?

Answer 344

Tail - splenic artery

head - gastroduodenal artery + inferior pancreaticduodenal artery (from SMA)

Question 345

What is the function of thromboxane A2?

Answer 345

Increases platealet activation and vascular tone

Question 346

What are the functions of the prostaglandins?

Answer 346

PGE1 = lower vascular tone (alprostadil)

PGE2 (dinoprostone) and PDF2a (carboprost) increase uterine tone.

Question 347

What is the most common side effect for niacin therapy? How do you prevent it?

Answer 347

Flushing due to prostaglandins

add aspirin.

Question 348

What therapy can be used for SIADH?

Answer 348

ADH antagonists: conivaptan, tolvaptan, demeclocycline

Question 349

What is indomethacin? what is it used for?

Answer 349

NSAID - used to close a PDA, in addition to fever / pain / stiffness from inflammation

Question 350

An intension tremor results from what localization of lesion?

Answer 350

Ipselateral cerebellar hemisphere

Question 351

How do you calculate the likelihood of having a child with an AR disorder that occurs 1 in x amount of individuals?

Answer 351

First figure out what the carrier frequency is i.e. 2pq.

remember that for AR it’s a 1 in 4 chance 2 carriers produce a child with the disease.(2pq)^2 x 1/4 = d

Question 352

Identify the locations of CN5 through 12 on this image

Answer 352

A – CN5

B - CN7

C - CN8

D - CN9

E CN10

below E is CN11

CN12 is midline

Question 353

What cell types are acted on by cGMP with PDE-5 inhibitors?

Answer 353

smooth muscle cells (relaxation)

Question 354

What treatment is useful for male pattern baldness?

Answer 354

Finasteride - blocks conversion of T to DHT.

Question 355

What animals are associated with Coxiella burnetii

Answer 355

Q fever - cattle or sheep amniotic fluid

Question 356

What mechanism prevents peripheral tissue edema with increased diastolic BP?

Answer 356

Precapillary resistance

Question 357

Describe what happens histologically with Hashimoto’s?

Answer 357

replacement of thyroid parenchyma by lymphoid cells

Question 358

How does prostatic adenocarcinoma spread?

Answer 358

via Batson / vertebral venous plexus.

Question 359

What BUN:creatinine values are consistent with prerenal azotemia?

Answer 359

>20

Question 360

Which neurotransmitter is associated with the locus ceruleus? How does it change in anxiety and depression?

Answer 360

Norepinephrine, up in anxiety, down in depression.

Question 361

Which neurotransmitter is associated with the raphe nuclei? Where are they located?

Answer 361

Serotonin

Located in the medulla and pons

Question 362

Which vaccines use killed or inactivated virus? What is the immune response to this type of vaccination?

Answer 362

A TRIP could Kill you

Hep A

Typhoid

Rabies

Influenza

Polio (salK)

humoral response.

Question 363

What are the nitrosoureas? what are they used for?

Answer 363

carmustine & lomustine

Cross BBB & x-link DNA, used for brain tumors

Question 364

What is cytosine arabinoside? what is it used for?

Answer 364

Cytarabine used for DNA chain termination in the treatment of AML & lymphomas

Question 365

What are the attachments of the rotator cuff muscles?

Answer 365

A - teres minor

B - infraspinatus

C- supraspinatus

D - subscapularis

Question 366

What drugs are used for acute treatment of gout? Chronic treatment?

Answer 366

Acute gout: NSAIDs, steroids or colchicine

Chronic gout: probenecid, allopurinol, pegloticase or febuxostat

Question 367

How would you differentiate fibromuscular dysplasia from polyarteritis nodosa

Answer 367

Both present with “string of pearls” on renal angiogram, but polyarteritis nodosa is microaneurysms and spasms assoc with hepatitis B (30% of cases) and middle-aged men

Fibromuscular dysplasia looks like a series of beads on the renal artery and often found in young women.

Question 368

label the tracts A through D. Which ones ascend ipsilaterally vs contralaterally?

Answer 368

Dorsal columns: pressure, vibration, fine touch and proprioception. A fasciculus gracilis (lower body); B fasciculus cuneatus (upper body). Ascends ipsilaterally in cord

Lateral cortcospinal tract: voluntary motor C descends ipsilaterally

Spinothalamic tract: antreior is crude touch/pressure, lateral is pain/temp. D ascends contralaterally as it decussates in spinal cord at anterior comissure.

Question 369

What are the drugs that are ADP receptor inhibitors? What is their mechanism? What are they used for?

Answer 369

Clopidogrel, prasugrel, ticagrelor, ticlopidine

Block platelet aggregation due to prevention of glycoprotein IIb/IIIa on cell surface

Used for acute coronary syndrome, post-stenting

Question 370

Which adrenergic & cholinergic receptors are associated with sphincter contraction, bladder contraction, and bladder relaxation?

Answer 370

alpha-1 = sphincter contraction

M3 = bladder contraction

beta-3 = bladder relaxation

Question 371

If your exact calculation results in an answer that isn’t one of the answer choices, what do you do?

Answer 371

Go for the closest answer choice; sometimes they round the numbers that they use in their own calculation.

Question 372

What neoplasms are associated with hypercalcemia?

Answer 372

SCC of lung, head and neck, renal, bladder, breast and ovarian cancers can produce PTHrP

Lymphoma can produce increased calcitriol

Question 373

What are the tick-born illnesses?

Answer 373

Rickettsia ricketsii (rocky mountain spotted fever)

Typhus (R. typhi)

Ehrlichosis (monocytes with morulae), anaplasmosis (granulocytes with morulae)

Question 374

What diseases are transmitted by the Ixodes deer tick

Answer 374

Lyme disease (Borrelia burgdorferi), Anaplasma and Babesia

Question 375

What pattern on PFT is associated with asbestosis? What findings on CXR?

Answer 375

Normal FEV1/FVC, decreased FVC and decreased DLCO

CXR: diffuse parenchimal opacities with reticular pattern and bilateral pleural plaques

Question 376

What are the allergic and acute hemolytic transfusion reactions?

Answer 376

Allergic = type I reaction against plasma proteins with degranulation of mast cells (urticaia, pruritis, anaphylaxis)

Acute hemolytic = type II reaction due to preformed anti-A or anti-B IgG or IgM antibodies

Question 377

What is the mechanism through which HER2/neu causes cancer?

Answer 377

Overexpression due to amplification

Question 378

When does loss of heterozygosity lead to cancer?

Answer 378

When it involves a tumor suppressor gene.

Question 379

How do you handle sharing bad news when the patient’s family or friends are also present.

Answer 379

Ask to speak with the patient first and or their partner before disclosing to family based on their wishes.

Question 380

What is the testicular tumor? what are the key features?

Answer 380

Seminoma

painless germ cell tumor; large cells in lobules with watery cytoplasm and “fried egg” appearance

Question 381

What complement is involved in SLE?

Answer 381

C1q, C4 and C2 (early complement deficiency)

Question 382

Where in the nephron is phosphate primarily reabsorbed?

Answer 382

The proximal convoluted tubule

Question 383

How would you differentiate between ARDS and atelectasis?

Answer 383

ARDS = alveolar insult leading to intra=alveolar transudates and formation of hyaline membranes. Bilateral lung opacification.

Atelectasis is alveolar colapse due to contraction/scarring, compressive lesion or airway obstruction (NRDS in babies)

Question 384

How would you differentiate between hypertension associated with pheochromocytoma vs hyperaldosteronism

Answer 384

Pheo comes in spells - would be associated with catecholamines and metanephrines

Hyperaldosteronism is HTN all the time, suspect if renal bruit (secondary)

Question 385

What pathogen is this? What complications can result?

Answer 385

Malaria; falciparum can cause lactic acidosis and hypoglycemia, occlusion of capillaries in brain, kidneys and lungs.

Question 386

What is the mechanism of action for acetazolamide? How does it reduce intracranial pressure?

Answer 386

Acetazolamide inhibits carbonic anhydrase. It alkalinizes urine. Decreases CSF production by choroid plexus, potentially by reducing Na/K ATPase activitity.

Question 387

Which nematodes infect hosts via ingestion?

Answer 387

EATTT

Enteriobius (tape test, anal itching), Ascaris (giant roundworm), Toxocara (visceral larva migrans), Trichinella (encyst in muscles), Trichuris (asymptomatic, loose stools, anemia, rectal prolapse in children)

Question 388

Which nematodes infect hosts directly through skin?

Answer 388

Strongloides (GI / pulmonary / cutaneous), Ancylostoma & Necator (microcytic anemia) (SANd)

Question 389

Which nematodes infect via bites?

Answer 389

Loa loa (worm in conjunctiva, skin swelling), Onchocera volvulus (river blindness), Wucheria bancrofti (elephantiasis) (lay LOW)

Question 390

When someone who is “anxious” is experiencing sinus tachycardia, what happens to their ABGs?

Answer 390

Hyperventilation -> PCO2 drops

Question 391

How would you explain a disappearance of howell-jolly bodies after splenectomy?

Answer 391

An accessory spleen

Question 392

What is wide splitting of S2 associated with?

Answer 392

Exaggeration of physiologic split due to delay in RV emptying e.g. pulmonic stenosis, RBBB

Question 393

What is fixed splitting of S2 associated with?

Answer 393

Atrial septal defect delays pulmonic valve closure regardless of respiration

Question 394

What is paradoxical splitting of S2 associated with?

Answer 394

P2 before A2 due to delayed closure e.g. aortic stenosis or LBBB. Opposite of physiological split.

Question 395

Weakness to external rotation of the shoulder = what muscle?

Weakness to internal rotation of the shoulder = what muscle?

Answer 395

External rotation = infraspinatus

Internal rotation = subscapularis

Question 396

What serum findings are consistent with adrenal insufficiency?

Answer 396

Hyponatremia + hypotension

Hyperkalemia

Metabolic acidosis

Question 397

What is the cause of postnatal hypoglycemia in infants of diabetic mothers?

Answer 397

Hyperinsulinemia impairs gluconeogenesis.

Question 398

How would you diffrentiate between gastroschisis and omphalocele?

Answer 398

Gastroschisis is not covered by peritoneum, abdominal contents come out through gap in abdominal folds (R of umbilicus).

Omphalocele is associtaed with congenital abnormality eg T13/18; contents surrounded by peritoneum coming out through persistent midline herniation of contents into cord.

Question 399

How does failure of vitelline duct obliteration present? what about a patent urachus?

Answer 399

Vitelline fistula -> meconium coming out of umbilicus; meckel diverticulum is partial closure

Patent urachus is urine coming out of umbilicus, or urachal cyst / diverticulum

Question 400

How would you differentiate between paget disease and prostatic adenocarcinoma bone mets

Answer 400

Paget disease = osteocsclerotic or osteolytic areas

Prostatic mets = high PSA, osteoblastic lesions

Question 401

superficial peronial nerve ensury is most likely occur due to pressure at which site?

Answer 401

Neck of the fibula

Question 402

What causes inherited HOCM?

Answer 402

Autosomal dominant due to genes encoding myosin binding protein C and beta-myosin.

Question 403

How does serum ACTH and the dexamethasone suppression test help with the differential for cushing syndrome?

Answer 403

Low ACTH -> ACTH independent likely exogenous glucocorticoids or adrenal tumor

Elevated ACTH -> either pituitary adenoma (suppressed by dexamethasone) or ectopic ACTH (no suppression)

Question 404

How will intracellular and extracellular volume and osmolality change in response to hypertonic IV saline?

Answer 404

Intracellular decreased volume and increased osmolality

Extracellular increased volume, increased osmolality

Question 405

What is the mechanism of action for azoles?

Answer 405

Inhibit fungal ergosterol synthesis via cytochrome P450 inhibition.

Question 406

what are the spinocerebellar tracts?

Answer 406

Convey proprioceptive information and located on the outer edges of the cord.

Question 407

What congenital abnormailty is caused by failed closure of the caudal neuropore? What about the rostral neuropore?

Answer 407

Failure of caudal neuropore needs to spina bifida

Failure of rostral neuropore (anterior) is anencephaly

Question 408

Which viral infections are more common with low T cells?

Answer 408

CMV, EBV, JC and VZV or chronic resp/GI infections

Question 409

What is the stellate ganglion?

Answer 409

The cervicothoracic ganglion is a sympathetic ganglion located at C6/7

Question 410

Hypogonadism, hepatomegaly and diabetes mellitus would be associated with what serum abnormalities?

Answer 410

Hemochromatosis: high serum iron and ferritin; low transferrin/TIBC and high transferrin saturation

Question 411

What do you do if a patient directly asks you about results you have been asked not to share?

Answer 411

Go ask resident / staff; don’t share the results.

Question 412

What lung cancers present centrally? Peripherally?

Answer 412

Central: small cell carcinoma, squamous cell carcinoma

Peripheral: adenocarcinoma (only one common in non-smokers) or large cell carcinoma

Either: bronchial carcinoid

Question 413

What is the diagnosis based on this liver? What is the most common liver mets?

Answer 413

Colon >> stomach > pancreas

Question 414

Renal failure: how does it affect phosphate, calcium and PTH?

Answer 414

PTH up (secondary to renal failure), low C (secondary to low calcitriol), phosphate high.

Question 415

What is the difference between borderline and dependent personality

Answer 415

Borderline: unstable mood & interperosnal relationships, fear of abandonment, suicidality, emptiness

Dependent: submissive and clingy, excessive need for support, low self-confidence.

Question 416

What is the cause of endometrial hyperplasia?

Answer 416

Usually associated with excess estrogen binding

Question 417

What is the treatment of cholera?

Answer 417

Rehydration (oral / IV)

Question 418

What are the symptoms of a basilar artery stroke?

Answer 418

Loss of horizontal but not vertical eye movements, quadriplegia and loss of voluntary movements of face, mouth and tongue. “Locked-in” the basement.

Question 419

How would you differentiate ketamine from methamphetamine abuse?

Answer 419

While both are sympathomimetics, ketamine would be typically associated with disociative symptoms & duration around 30mins-1hr. methamphetamine lasts 4-12 hours

Question 420

What does the liver look like in hepatitis A, B and C

Answer 420

A - swollen hepatocytes with monocyte infiltration and councilman bodies

B - eosinophilic ground glass appearance

C - lymphoid aggregates with focal areas of macrovesicular steatosis

Question 421

Why is tetracycline contraindicated in pregnancy and children?

Answer 421

Inhibits bone growth

Question 422

Why is ritonavir given in combination with a second protease inhibitor?

Answer 422

It is a cyt P450 inhibitor so it increases concentrations of other protease inhibitors

Question 423

What derivative of arachidonic acid is responsible for promoting bronchospasm? What enzime is responsible for making 5-HPETE?

Answer 423

5-hydroperoxyeicosatetraenoic acid (5-HPETE) makes leukotrienes (LTC/D/E-4 increases bronchial tone)

5-lipoxygenase (inhibited by zileuton)

Question 424

What is the arterial supply to the testes?

Answer 424

Main via testicular artery (branch of aorta)

Collateral supply by branches of the cremasteric arteries (off inferior epigastric) and artery of the vas deferens (off inferior vesical artery)

Question 425

Identify the lesion. What management is indicated?

Answer 425

Hemangioma - no intervention needed, most will fade by age 10

Question 426

What is the primary effect of statins?

Answer 426

Blocks cholesterol synthesis in liver, increases LDL recycling (i.e. more LDL-R expression)

Question 427

When asked about vitamin D levels, before answering, what must you clarify?

Answer 427

Whether it is asking about 25-OH-Vitamin D (inactive) or 1-25-OH-Vitamin D (active)

Question 428

How would you distinguish polyneuropathy from syringomyelia?

Answer 428

Syringomyelia will present with loss of pain & temp sensation in a cape-like bilateral distribution

Polyneuropathy presents with symptoms in multiple nerve distributions & can be sensory and/or motor.

Question 429

What is the location of a tumor that produces a vertigal gaze palsy and loss of near-vision accomodation? What is the name for this syndrome? What other symptoms may present? What is the histology?

Answer 429

Pinealoma; Parinaud syndrome

Causes obstructive hydrocephalus and precocious puberty in boys.

Similar to germ cell tumor

Question 430

What is the presentation of a lesion in the paramedian pontine reticular formation?

Answer 430

Eyes that look away from the lesion (towards the hemiplegia)

Question 431

What is the most likely cause of abdo pain that radiates to the scrotum without peritoneal signs or any scrotal masses?

Answer 431

A kidney stone

Question 432

What is the classic presentation of testicular torsion?

Answer 432

Acute pain, loss of cremasteric reflex, boggy, high-riding testicle

Question 433

How do changes in afferent and efferent arteriole diameter affect kidney RPF, GFR and FF?

Answer 433

Dilation of afferent = increased RPF and GFR, same FF
Constriction of efferent = decreased RPF, increased GFR, increased FF

Question 434

What is the mechanism that maintains renal blood flow across a range of perfusion pressures?

Answer 434

The myogenic response of the afferent arterioles.

Question 435

What is the most likely cause of postprandial pain with weight loss and food aversion in the presence of an ectatic abdominal aorta (AAA)?

Answer 435

Chronic mesenteric ischemia involving SMA &/or IMA

Question 436

What channel is affected by tetrodotoxin (puffer fish) and ciguatoxin (reef fish, barracuda, snapper, moray eel)?

Answer 436

Tetrodotoxin blocks Na+ channels

Ciguatoxin opens Na+ channels

Question 437

What is the vector and clinical presentation of Onchocerca volvulus infection? How do you treat it?

Answer 437

River blindness transmitted by female black fly

Black skin nodules, black sight, skin changes / loss of elastic fibres

Ivermectin

Question 438

What enzyme synthesizes epinephrine from norepinephrine? How is it regulated?

Answer 438

phenylethanolamine-N-methyltransferase

Induced by cortisol

Question 439

Distinguish between the 3 types of renal tubular acidosis.

Answer 439

Type 1: DCT unable to excrete H+ (amphotericin B toxicity, urinary tract obstruction, SLE), results in low K+ and increased risk of Ca/PO4 stones

Type 2: PCT due to inability to resorb HCO3- (Fanconi syndrome, MM, acetazolamide), also results in low K+

Type 4: Hyperkalemic due to hypoaldosteronism or resistance; high K+ reduces PCT NH3 synthesis and NH4+ excretion.

Question 440

What is the most common side-effect of the beta-2 agonists (albuterol / terbutaline)

Answer 440

Uncontrollable shaking (tremor)

Question 441

What is the vanilloid receptor?

Answer 441

AKA capsaicin receptor or TRPV1

Pain & temperature sensor, produces burning pain when activated.

Question 442

What cells synapse in the dorsal root ganglion?

Answer 442

None - the dorsal root gangion holds the cell bodies of the pseudounipolar 1st order neurons.

Question 443

When trying to decide between two answers which seem equally likely, what should you do?

Answer 443

Focus on seeing if you can prove one answer wrong or find something that makes it less likely to be correct.

Question 444

What is the primary mechanism by which DKA causes altered level of consciousness?

Answer 444

Osmotic diuresis (due to glucose) leads to dehydration.

Question 445

Where do flexor digtorum profundis and superficialis insert?

Answer 445

Deep flexor -> tendon inserts on the distal phalanges

Superficial -> tendon divides and inserts on the middle phalanges.

Question 446

What is/are the name(s) of human lice? What diseases can be spread by them?

Answer 446

Pediculus humanus & Pthirus pubis

Rickettsia prowazekii (typhus), Borrelia recurrentis (relapsing fever) and Bartonella quintana (trench fever) spread by body lice

Question 447

What is the difference between transfusion-related lung injury and anaphylaxis?

Answer 447

Both present rapidly within minutes to hours of starting transfusion

Anaphylaxis due to allergic reaction (type I) and presents with wheezing, hypotension, respiratory arrest, shock

Transfusion-related lung injury due to sensitized neutrophils releasing inflammatory cytokines causing pulmonary edema, resp distress.

Question 448

What hormones are produced from pro-opiomelanocortin? How?

Answer 448

Post-translational cleavage of pro-opiomelanocortin produces beta-endorphins, ACTH and MSH (go pro with a BAM)

Question 449

An immediate reaction of malignant hypertension would be caused by which agent?

Answer 449

Succinylcholine

(nb faster acting than rocuronium & more likely to cause rigidity)

Question 450

What is bronchiolitis obliterans?

Answer 450

Chronic lung transplant rejection

Question 451

What is the cause of a spina bifida?

Answer 451

Failure of the fusion of the sclerotomes

Question 452

Under what situations would you expect pulmonary capillary wedge pressure to be elevated?

Answer 452

Left ventricle failure, mitral valve pathology, cardiac insufficiency, cardiac compression post hemorrhage

Question 453

Where in the nephron does nephrotoxicity due to aminoglycosides occur?

Answer 453

Straight limb of proximal convoluted tubule

Question 454

What is/are the most likely organisms in acute prostatitis?

Answer 454

Young men - Chlamydia trachomatis or Neisseria gonorrhoeae

Older men - E coli most common

Question 455

For CF, if only one mutated allele is identified by the panel molecular analysis yet sweat test is positive, what is the most likely explanation?

Answer 455

The second mutation is not part of the panel.

Question 456

What is the presentation of opioid withdrawal?

Answer 456

Sweating, dilated pupils, piloerection (cold turkey), rhinorrhea, lacrimation, yawning, nausea, stomach cramps, diarrhea (flu-like symptoms)

Question 457

Do lesions of the corticospinal tract produce UMN or LMN sympotms? What would be the expected presntation?

Answer 457

UMN signs

Weakness, hyperreflexia, hypertonia, upgoing babinski, spactic paresis / clasp-knife.-

Question 458

When in the cell cycle are mitotic cyclins synthesized?

Answer 458

G2 (they control the progression into mitosis)

Question 459

What is the leading cause of melanoma in darker-skinned individuals? Where is it found

Answer 459

Acral lentiginous melanoma on the palms of hands or soles of feet or in the nail.

Question 460

What viruses have negative-sense RNA for genetic material?

Answer 460

Always Bring Polymerase Or Fail Replication

Arenaviruses

Bunyavirus

Paramyxovirus

Orthomyxovirus

Filovirus

Rhabdovirus

Question 461

What are the paramyxoviruses? What virulence factor do they all make?

Answer 461

Parainfluenza (croup)

Measles & Mumps

RSV

F protein causes resp epi to fuse and form multinucleated cells

Question 462

Identify the type of tissue

Present 18 days post MI

Answer 462

Granulation tissue

Question 463

What is the presentation of interstial i.e. restrictive lung diseases?

Answer 463

Low lung volumes (Low FVC, TLC, DLCO)

Increased Alveolar-arterial PO2 gradient

Question 464

What are the 4 lung volumes

Answer 464

LITER
Inspiratory resrve volume

Tidal volume

Expiratory reserve volume

Residual volume

Question 465

What are the 4 lung capacities?

Answer 465

Inspiratory capacity = IRV + TV

Functional residual capacity = RV + ERV

Vital capacity = maximum volume of gas expired after maximal inspiration (TV + IRV + ERV)

Total lung capacity = Volume of gas in lungs after maximal inspiration (TV + IRV + ERV + RV)

Question 466

What is myositis ossificans?

Answer 466

Metaplasia of muscle -> bone after trauma.

Question 467

How would you differentiate between the two main causes of renal artery stenosis?

Answer 467

Atherosclerosis if prox 1/3 of renal artery, usually older, male, smoker

Fibromuscular dysplasia if distal 2/3 of renal artery or segmental branches, young-to-middle-age females

Question 468

Where does the breakdown of dipeptides and tripeptides to free AAs take place?

Answer 468

In the intestinal lumen

Question 469

A schwannoma originates from what type of cells?

Answer 469

Neural crest cells or Schwann cell origin

Question 470

What is the relevance of synaptobrevin?

Answer 470

One of 4 proteins in SNARE complex, bound by tetanospasmin and several botulinum toxin serotypes

Question 471

What physiologic events will lead to swelling of parenchymal cells in a person with an MI?

Answer 471

Decrease in intracellular ATP concentrations subsequent to hypoxemia / hypoperfusion

Question 472

What are the side effects of NRTIs?

Answer 472

Bone marrow suppression, peripheral neuropathy, lactic acidosis with nucleosides, anemia with zidovudine, pancreatitis with didanosine

Do not use abacavir in HLA B*5701

Question 473

When a patient has a collapsed lung, what is the complication for which they are at highest risk?

Answer 473

Respiratory acidosis due to hypoventilation

Question 474

What is the therapy for nematodes?

Answer 474

Intestinal - bendazoles, ivermectin for Strongyloides stercoralis

Tissue - Bendazole for toxocara, Ivermectin for river blindness, diethylcarbamazine for Loa loa and Wucheria bancrofti

Question 475

What are the atypical lymphocytes in EBV/mononucleosis?

Answer 475

reactive cytotoxic (CD8+) T cells

Question 476

What are the units of clearance? How would you calculate infusion rate to maintain a given steady state concentration C

Answer 476

Clearance is the volume of plasma cleared of drug per unit time i.e. mL/min

Cl x C = steady state infusion rate

Question 477

What is the diagnosis? What would be seen on microsocopy?

Answer 477

Chronic pyelonephritis, often due to reflux (in children) or obstruction (not in children)

Interstitial inflammation

Question 478

What is the microscopic presentation of kaposi sarcoma?

Answer 478

Slit-like vascular spaces due to spindled epithelial cells.

Kaposi = vascular neoplasm due to HHV8

Question 479

What is the effect of acetazolamide on urinary pH and bicarbonate?

Answer 479

Blocks resorption of HCO3- leading to alkaline urine.

Question 480

What are the diagnostic criteria of antiphospholipid syndrome? What are the lab findings?

Answer 480

Arterial or venous thrombosis or spontaneous abortion

Increased PTT, lupus anticoagulant, anticardiolipin (false positive VRDL), anti-B2 glycoprotein I antibodies

Question 481

What are the consequences of renal failure?

Answer 481

MAD HUNGER

Metabolic Acidosis

Dyslipidemia

High K+

Uremia

Na+ & H2O retation

Growth retardation/ developmental delay

Erythropoetin deficiency

Renal osteodystrophy (Low D3, low Ca2+ high PO4 and high PTH)

Question 482

What are the most common adverse effects of nitrates?

Answer 482

Reflex tachy, hypotension, flushing, headache, and monday disease (loss of tolerance to vasodilating action over weekend)

Question 483

How is glucosamine synthesized in humans? What are the downstream products of this biosynthetic pathway

Answer 483

F-6P + glutamine -> glucosamine

via F-6P transaminase

Question 484

What is entrapment neuropathy? What are common examples?

Answer 484

Nerve compression due to inflammation in a narrow space.

Carpal tunnal, cubital tunnel, guyon’s, radial compression, suprascapular compression and meralgia paraesthetica.

Question 485

What is the nerve supply to the medial flexor digitorum profundus? What are the nerve roots?

Answer 485

Ulnar: C8/T1

Question 486

How does the length of the mature heavy chain gene compare to the unrearranged gene?

Answer 486

Mature gene is shorter due to deletion of unwanted V, D, and J segments

Question 487

What are the electrolyte changes that occur in early MI?

Answer 487

Increased Na +, decreased K+ due to low ATP and shutdown of Na/K+ pump

High Ca2+ due to reperfusion injury -> hypercontraction of myofibrils (wavy fibres)

Question 488

Why would a patient with a 2week hystory of viral symptoms and positive plasma HIV viral load have a negative serum antibody test?

Answer 488

Window period = acute infection

Question 489

What is the appropriate test to determine if the prevalence of hypertension is significantly different between 2 populations?

Answer 489

Chi-square test

Question 490

What are the changes in insulin, testosterone and LH:FSH in PCOS?

Answer 490

High insulin causing increased LH:FSH ratio, increased testosterone & androgens

Question 491

What is the enzyme that is inhibited by fluorouracil?

Answer 491

Thymidylate synthase (responsible for dTMP synthesis)

Question 492

label A,C,D,E

Answer 492

A- thalamus

B - internal globus pallidus???

C - subthalamic nucleus

D - Substantia nigra

E - hippocampus

Question 493

Differentiate between tuberous sclerois and neurofibromatosis-1

Answer 493

Tuberous sclerosis has lighter ash-leaf spots, seizures and kidney disease, wherease NF-1 has darker cafe-alu-lait spots, lisch nodules or bone lesions, axilary/inguinal freckling

Question 494

What is the mechanism of action of dextromethorphan?

Answer 494

NMDA-glutamate antagonist / synthetic codeine analogue. No constipation

Question 495

What are ipatropium and tiotropium used for?

Answer 495

COPD and asthma

Question 496

What hepatic vascular injury is most likely to occur with blunt abdominal trauma?

Answer 496

Avulsion of the hepatic veins from the IVC

Question 497

What are transference and countertransference?

Answer 497

Transference = patient projects feeling about important or formative persons onto doctor

Countertransference = doctor projects feelings about significant people onto the patient

Question 498

What is the innervation of the scrotum?

Answer 498

Anteriorly - ilioinguinal and genitofemoral nerve

Posteriorly - perineal branches of pudendal nerves

Question 499

How long will it take to remove all erythrocytes exposed to CO?

Answer 499

Basically, it’ll take as long as the longest remaining lifespan of the erythrocytes i.e. 120 days = 4 months

Question 500

What is this organism? What disease and what symptoms are associated with it?

Answer 500

Trypanosoma cruzi

Chagas disease; acute unilateral periorbital swelling is characteristic, followed by megaesophagus, megacolon, dilated cardiomyopathy (edema, crackles)

Question 501

What genetic mechanism helps staph aureus adapt to different environments in the body and evade the immune system?

Answer 501

Phase variation - “phase variable genes” have regions which can be quickly mutated to turn genes on or off.

Question 502

What is the appropriate therapy in a bradycardic patient with 3rd degree heart block?

Answer 502

Insert a transvenous pacemaker

Question 503

What are the characteristics of yersinia enterocolitica?

Answer 503

Gram -ve pleiormorphic coccobacillus often from pet feces, contaminated milk or pork. Causse bloody diarrhea and pseudoappendicitis and reactive arthritis

Can grow at 4C

Question 504

What are the side effects of TCAs? What side effects tend to be problematic for compliance?

Answer 504

Sedation

alpha-block = postural hypotension

Anticholinergic = tachy, urinary retention, dry mouth

3Cs: Convulsions, coma and cardiotoxicity

Long QT

Question 505

What process would be disrupted by a mutation to a gene’s TATA box?

Answer 505

Transcription by RNA polymerase

Question 506

What are the key diagnostic criteria of peripartum cardiomyopathy?

Answer 506

HF within last month of pregnancy or <5 months post-delivery

Reduced ejection fraction

Diagnosis of exclusion (rule out other causes of heart failure)

Question 507

What vascular changes occur in the setting of severe, uncontrolled HTN?

Answer 507

Hyperplastic or “onion skin” arteriosclerosis due to proliferation of smooth muscle cells

Question 508

What is the ligament of Treitz? Why is it important

Answer 508

Suspensory fold of peritoneum at the duodenojejunal flexure - diagnostic of malrotation if located on the right of the abdomen. Involutes in adults

Question 509

What is the embryonal origin of the pancreatic islets?

Answer 509

The pancreas is derived from foregut = endoderm

Question 510

Muscle strength that improves with repetitive testing suggests which diagnosis?

Answer 510

Lambert-eaton myasthenic syndrome, as repeated stimulation increases ACh release (unlike MG where muscle weakness is worse with use)

Question 511

What is the mechanism of adenosine deaminase deficiency?

Answer 511

ADA degrased adenosine and deoxyadenosine leading to increase in dATP and inhibition of ribonucleotide reductase -> lympotoxicity & SCID

Question 512

What happens to the lysosomal enzymes in I-cell disease patients?

Answer 512

They are secreted from the cell due to lack of mannose-6-phosphate tag

Question 513

How do you calculate lung compliance?

Answer 513

Tidal volume / (peak inspiratory pressure - positive end-expiratory pressure)

Question 514

Where does niacin act to reduce LDL?

Answer 514

Inhibits lipolysis in adipose tissue and reduces hepatic VLDL synthesis

Question 515

How does parvovirus B19 infection lead to anemia?

Answer 515

Results in interruption of erythrocyte production esp in sickle cell or immunocompromise

Question 516

What is appropriate therapy for chlamydia in a pregnant woman?

Answer 516

Azithromycin

Question 517

Do you need to adjust the loading dose given to a patient with renal compromise?

Answer 517

No; loading dose stayst the same.

Question 518

Adults who are treated with previous chemotherapy or radiation are at increased risk of what cancer? What are the characteristic cells?

Answer 518

Acute myeloid / myelocytic leukemia.

Blasts

Question 519

Salt wasting hyponatremia in a newborn with increased 17-hydroxyprogesterone is due to a deficiency in which enzyme?

Answer 519

21-hydroxylation.

Question 520

What’s the easy to remember rule for the adrenal enzyme deficiencies?

Answer 520

If it starts with a 1, it causes hypertension if absent

If it ends with a 1, it causes virilization in females

Question 521

With intrauterine transfusion, what is the appropriate blood type?

Answer 521

O, Rh-ve

Because Rh-ve blood will not trigger an Rh +ve reaction

Question 522

A distal tibial fracture suggests what movement?

Answer 522

Eversion

Question 523

In the setting of chronic heart failure, what causes hyponatremia?

Answer 523

Dilution of serum sodium due to ADH secretion

Question 524

what is the presentation of a cervical rib?

Answer 524

Thoracic outlet syndrome - lower trunk and subclavian compression resulting ulnar neuropathy

Question 525

What electrolyte abnormalities occur in laxative abuse?

Answer 525

Hypokalemia, hypochloremia, hypocalcemia and metabolic acidosis

Question 526

name the major branches of the aortic order and their respective vertebral levels

Answer 526

T12 = celiac trunk

L1 = SMA

L1/L2 = Renal

L2 = Testicular/ovarian

L3 - IMA

L4 = bifurcation to common iliacs

Question 527

What is the presentation of C1 esterase inhibitor deficiency? What is the treatment?

Answer 527

Hereditary angioediema due to elevated bradykinin, low C4 levels.

Treat with danazol and stanozolol.

Question 528

What is the left hip pathology?

Answer 528

Avascular necrosis of femur

Question 529

What is deficient in NRDS?

Answer 529

Dipalmitoyl lecithin