UWorld Practice Questions #1

Question 1

What are the two classes of Ca channel blockers and how do their effects differ?

Answer 1

Dihydropyridines (nifedipime, amlodipine, etc.) are primarily vasodilatory w/ minimal effect on cardiac contractility or conduction.

Non-dihydropyridines (verapamil, diltiazem) affect the cardiac muscle to slow contractility and conductance.

Question 2

What is the complement component that is deposited in glomeruli in PSGN?

Answer 2

C3. Note that the pts will have decreased levels of C3, IgG and IgM due to immune complex deposition.

Question 3

What do patients with tetralogy of fallot squat when they become cyanotic?

Answer 3

This increases the systemic vascular resistance (afterload) which reduces their R to L shunt and thus reduces hypoxemia.

Recall that tetralogy of fallot comes from deviation of the infundibular septum.

Question 4

What is the major determinant of the ratio of forward to reverse flow in mitral regurgitation (i.e. mitral valve prolapse)?

Answer 4

L ventricular afterload. The lower it is, the higher that ratio will be.

Question 5

What is first line treatment for trigeminal neuralgia? What is the mechanism of action?

Answer 5

Carbamazepine. It works by blocking Na channels.

One ADR is bone marrow suppression.

Question 6

What steps/enzymes in the TCA cycle are thiamine dependent and could be impaired in the setting of Wernicke’s encephalopathy due to thiamine deficiency?

Answer 6

Pyruvate dehydrogenase (forming acetyl CoA from pyruvate) and alpha-ketoglutarate dehydrogenase complex (froming succinyl CoA from alpha-ketoglutarate) are both thiamine dependent.

Question 7

In terms of damage, which side of the frontal lobe is associated more with apathy and depression, and which side is more associated w/ disinhibition

Answer 7

L side –> apathy and depression

R side –> disinhibition

Question 8

How can one make the clinical dx of narcolepsy?

Answer 8

Decreased levels of hypocretin-1 in the CSF or shortened REM onset latency on sleep study.

Question 9

Are high (i.e. fluphenazine) or low (i.e. chlorpromazine) potency typical anti-psychotics more like to cause ant-cholingergic, anti-histaminic, and alpha1-blockade associated side effects?

Answer 9

Low potency ones. Higher potency ones are more likely to cause the extra-pyramidal sxs that can be seen.

Question 10

What are two examples of true diverticulum (involve mucosa, submucosa and muscularis layers)? How about false diverticulum (involve just mucosa and submucosa)?

Answer 10

True –> Meckel’s diverticulum, the appendix

False –> Zenker diverticulum, diverticulosis.

Question 11

Hepatitis B has a proliferative phase and an integrative phase. Describe what is occurring during each:

Answer 11

At the proliferative phase, HBV is infecting cell (note virus is not directly cytotoxic) and the cell is presenting the HBV antigens via class I MHC. The response by CD8+ killer cells is what causes the inflammation and elevated LFTs.

In the integrative phase the HPV genetic material is incorporated into the host cell genome. This occurs when host organism has antibodies to the virus.

Question 12

Why is lowering PaCO2 (i.e. by adjusting the ventilator settings) sometimes employed in the treatment of diffuse cerebral edema?

Answer 12

Because PaCO2 is one of the potent regulators of brain blood flow and a drop in PaCO2 will cause vasoconstriction and increased resistance to cerebral blood flow. This will reduced the ICP which will beneficial for the cerebral edema.

Question 13

What are the mechanisms of DNA damage from ionizing radiation used therapeutically?

Answer 13

One is double stranded DNA breaks. The other is generation of oxygen free radicals which damage DNA and cells.

Question 14

What is the trinucleotide repeat in fragile X?

Answer 14

CGG on FMR1 gene

Question 15

In the citric acid cycle, which enzymes use NAD as a cofactor and which one uses FAD as a cofactor?

Answer 15

NAD –> isocitrate dehydrogenase and alpha-ketoglutarate dehydrogenase complex.

FAD –> succinate dehydrogenase.

Question 16

In which populations of patients is exagerated hyperthermia a concern for with administration of succinylcholine?

Answer 16

pts w/ crush or burn injuries, denervating injuries or diseases (i.e. quadrplegia or GBS), and those w/ myopathies.

Hyperkalemia can occur b/c the nicotinic ACh receptor on muscle cells is permeable to both Na and K and consistently being open can cause K+ leakage.

Question 17

For the following three, state whether they promote or reduce cholesterol solubility and thus promote or reduce likelihood of gallstone formation: heightened cholesterol concentration, bile salts, and phosphatidylcholine

Answer 17

• heightened cholesterol concentration: promote gallstone formation from cholesterol
• bile salts promote cholesterol solubility and thus reduce likelihood of gallstone formation
• phosphatidylcholine promotes cholesterol solubility and thus reduce likelihood of gallstone formation

Question 18

What sorts of things are primarily made up of type 1 collagen?

Answer 18

dermis, bone, tendons, ligaments, dentin, cornea, blood vessels, and scar tissue.

Question 19

What is the embryologic pathogenesis that produces transposition of the great vessels?

Answer 19

Instead of the aorticopulmonary septum developing spirally, it develops linearly.

Question 20

What sort of arrhythmia medications have constipation as a common side effect?

Answer 20

Non-dihydropyridine CCBs (verapamil > dilatazem)

Question 21

Where in the brain is vomiting from chemotherapy induced?

Answer 21

It is induced by the chemoreceptor trigger zone (CTZ) in the dorsal medulla, aka the area postrema. There are fenestrated vessels here so that the area postrema can sample chemicals in the blood and decide if vomiting is needed.

Question 22

What is the name of the drug that affects funny Na channels and slows heart rate w/o affecting inotropy or lusitropy?

Answer 22

Ivabradine

Question 23

What are the most common drugs that have zero order metabolism?

Answer 23

Ethanol, aspirin and phenytoin

Question 24

Which cells make major basic protein and what its function?

Answer 24

Eosinophils make MBP and it is a potent helminthotoxin.

Question 25

What sort of epithelium are the true vocal folds made of?

Answer 25

Stratified squamous epithelium, which is what HPV likes to infect.

Question 26

If left untreated, what are the signs and sxs of congenital hypothyroidism?

Answer 26

constipation, lethargy, hypotonia, large anterior fontanelle, macroglosia, and an umbilical hernia.

Question 27

Deficiency of which enzyme causes muscle bx to show glycogen accumulation in the lysosomes?

Answer 27

Deficiency of acid-alpha glucosidase (which helps break down glycogen). This is the type II glycogen storage disease aka Pompe disease.

Question 28

What is the marker for high infectivity for hepatitis B infection?

Answer 28

Presence of HBe antigen. Also having low HBeAb.

Question 29

What is a common nerve injury that results from supracondylar fracture of the humerus?

Answer 29

Injury to the proximal median nerve.

Question 30

What does the supraclavicular nerve innervate?

Answer 30

Supraspinatus and infraspinatus

Question 31

What sort of autoantibodies are characteristic of pemphigus vulgaris?

Answer 31

anti-desmoglein 1 and 3.

Question 32

A patient has symmetrical muscle weakness w/ muscle bx showing anti-nuclear and anti-Jo1 (aka anti histidyl-tRNA-synthetase) antobodies. What condition does this person likely have and what would muscle bx show?

Answer 32

Polymyositis. Bx likely shows endomysial mononuclear inflammatory infiltrate and patchy muscle fiber necrosis.

Question 33

How does obstructive and restrictive airway disease affect work of breathing at different parts?

Answer 33

In restrictive there is decreased elastic recoil and so there is increased WOB w/ increased elastic resistance. Thus, this favors quick, shallow breaths (i.e. pulm fibrosis).

Conversely, in obstructive disease there is increased WOB w/ increasing airflow resistance (i.e. exhalation) and so this favors slow, deep breathing.

Question 34

What is the function of thyroid peroxidase?

Answer 34

It catalyzes the oxidation of iodide to iodine, the iodination of tyrosine residues in thyroglobulin, and the iodotyrosine coupling reaction that forms T3 and T4.

Question 35

Which nerve is commonly injured in a supracondylar humerus fracture w/ anterolateral displacement? How about one with anteromedial displacement?

Answer 35

Anterolateral –> radial nerve (it runs lateral)

Anteromedial –> median nerve (can be accompanied by brachial artery injury as it runs w/ median nerve in this location).

Question 36

What is the ANOVA (analysis of variance) test used for?

Answer 36

To determine if there are any significant differences in the means of two or more independent groups.

Question 37

What are the five cofactors of the branched chain dehydrogenase complex?

Answer 37

Thiamine, lipoate, conezyme A, FAD, NAD.

Note that some patients receive benefit from high dose thiamine supplementation.

Question 38

In which patients is supplementation of tetrahydrobiopterin potentially beneficial? Why?

Answer 38

PKU patients. This is because tetrahydrobiopterin is a cofactor for phenylalanine hydroxylase and deficiency can result in phenylketonuria. Thus, supplementation can reduce phenylalanine levels.

Question 39

What is the result of the mutation in sickle cell?

Answer 39

It is a point mutation in the 6th codon of the B globin gene that results in a glutamic acid to valine substitution.

Question 40

GFR is approximately equal to the clearance of what substance?

Answer 40

Inulin. This is because inulin is neither excreted nor reabsorbed.

Question 41

True or false, CN XI passes through the posterior triangle of the neck?

Answer 41

True!

Question 42

What enzyme allows erythrocytes to undergo glycolysis w/o generating any net ATP?

Answer 42

Bisphosphoglycerate mutase. This allows conversion of 1,3-BPG to 2,3-BPG in RBCs and this is an important regulator of RBCs.

Question 43

Where in a cell is structural RNA like ribosomal RNA produced?

Answer 43

In the nucleolus. It makes the different subunits for ribosomes. All except the 5s rRNA are made there.

Question 44

What is the causative organism of fifth disease?

Answer 44

Parvovirus B19. This disease is characterized by the “slapped cheek” rash.

Question 45

How does the culture of coccidiomyces vary based on temperature in terms of what you see?

Answer 45

Coccidioides is a fungus characterized by endospores containing spherules when cultured at 37°C and branched hyphae when the organism is cultured at 25°C

Question 46

What does graft versus host disease of the liver most commonly show? What disease process does this most resemble?

Answer 46

lymphocytic infiltration w/ destruction of intrahepatic bile ducts, causing a risk in alk phos. This most closely resembles PBC.

Question 47

When is S3 heard best and at what position?

Answer 47

At the end of expiration by bell at apex of heart because at end of expiration lung volumes are smallest and this brings heart closest to chest wall.

Best heard in L lateral decubitus position.

Question 48

What is the presentation of bloom syndrome and what is the genetic defect?

Answer 48

Presentation = photosensitive rash, facial anomalies, growth retardation and immunodeficiency due to chromosomal instability and breakage.

It is due to a genetic defect in helicase.

Question 49

In most patients, which artery supplies the majority of the inferior surface of the heart?

Answer 49

The posterior descending artery supplies this area and in most pts it is a branch of the R coronary artery. They are said to be R heart dominant. In a smaller subset of pts (like 15%), this artery is a branch of the L circumflex artery and these pts are said to be L heart dominant.

Question 50

Which markers can be elevated (detected via amniocentesis) in neural tube defects where there is failure of the neural tube to close?

Answer 50

Alpha fetoprotein and acetylcholinesterase. This is because an opening persists btwn the neural tube and these things leak into the amniotic fluid.

Question 51

Which sorts of fats are NOT oxidized in the mitochondria and instead undergo a separate oxidation process in the peroxisome?

Answer 51

VLCFAs and some branched chain fatty acids.

Question 52

What is the equation for the attributable risk in the percent exposed? (i.e. could be used for determining what percent of a type of cancer is due to smoking if you know the RR of cancer in smokers vs. non-smokers).

Answer 52

Attributable risk in the percent exposed = 100 x [(RR-1)/RR]

Question 53

What is the equation for filtration fraction using RPF and GFR?

Answer 53

FF = GFR/RPF

Question 54

What does graft versus host disease of the liver most commonly show? What disease process does this most resemble?

Answer 54

lymphocytic invasion w/ destruction of intrahepatic bile ducts, causing a risk in alk phos. This most closely resembles PBC.

Question 55

Which vessel supplies the rectus abdominus and enters the muscle at the level of the arcuate line?

Answer 55

Inferior epigastric artery and vein.

Question 56

In a situation of hemolytic disease of the newborn with the first pregnancy, what is the likely blood type of mom and fetus?

Answer 56

Mom is likely type O and thus has IgG antibodies against A and B (of which the baby is one or the other). This is unique as A and B type mom’s usually make IgM to different fetal erythrocyte antigens and so no hemolytic disease of the newborn occurs.

Question 57

Define lead time bias:

Answer 57

It is when detection of a specific condition occurs at an earlier time than normal detection methods but such detection does not alter the natural course of disease so apparent increase in survival time is just because of earlier detection.

Question 58

Which markers can be elevated (detected via amniocentesis) in neural tube defects where there is failure of the neural tube to close?

Answer 58

Alpha fetoprotein and acetylcholinesterase. This is because an opening persists btwn the neural tube and these things leak into the amniotic fluid.

Question 59

What is a physical exam finding that can be seen in X-linked (Bruton’s) agammaglobulinemia?

Answer 59

Absence of tonsils

Question 60

What is seen on light microscopy in membranoproliferative glomerulonephritis? How about immunofluorescence?

Answer 60

light microscopy = basement mebrane splitting

immunofluorescence = granular deposits

Question 61

What is head bobbing with carotid pulsations indicative of?

Answer 61

Aortic regurgitation

Question 62

What are the derivatives of the first pharyngeal and aortic arches?

Answer 62

trigeminal nerve and maxillary artery (portion of it) respectively

Question 63

What are the derivatives of the second pharyngeal and aortic arches?

Answer 63

facial nerve and stapedial artery (which regresses I believe) respectively

Question 64

What are the derivatives of the third pharyngeal and aortic arches?

Answer 64

glossopharyngeal nerve and common carotid and proximal part of internal carotid arteries

Question 65

What are the derivatives of the four pharyngeal and aortic arches?

Answer 65

superior laryngeal branch of vagus nerve and true aortic arch and subclavian arteries respectively

Question 66

What are the derivatives of the sixth pharyngeal and aortic arches?

Answer 66

recurrent laryngeal branch of vagus nerve and pulmonary arteries and ductus arteriosus.

Question 67

What is the presentation of Fabry’s disease?

Answer 67

multiple angiokeratomas (small, reddish-black papules), acroparesthesia (intermittent peripheral paresthesias), and heat intolerance.

Caused by deficiency of alpha-galactosidase A.

Question 68

Embryonically, where do parafollicular C cells of the thyroid originate?

Answer 68

In the ultimobranchial bodies

Question 69

What does the falciform ligament do?

Answer 69

It attaches the liver to the anterior body wall.

Question 70

A defect in CD18 causes what disease? What is the presentation?

Answer 70

It causes leukocyte adhesion deficiency. Pts present w/ delayed separation of the umbilical cord, infections w/o pus formation and poor wound healing.

Question 71

What is the likely defect in patients that present in infancy or early childhood with disseminated mycobacterial disease?

Answer 71

Inherited defect in the interferon gamma signaling pathway.

Question 72

Injury to what nerve causes a trendelenburg gait?

Answer 72

Superior gluteal nerve. It innervates glut med, min and TFL.

Question 73

BRAF mutations are a RF for which thyroid cancer? How about RAS mutations?

Answer 73

BRAF –> papillary thyroid cancer (the one w/ orphan Annie nuclei on histo)
RAS –> follicular thyroid cancer

Question 74

What substance accumulates in the walls of vessels in Fabry’s disease?

Answer 74

Ceramide trihexoside

Question 75

What is the presentation of Fabry’s disease?

Answer 75

multiple angiokeratomas (small, reddish-black papules), acroparesthesia (intermittent peripheral paresthesias), and heat intolerance.

Question 76

In what disease is there pathologic accumulation of galactocerebroside?

Answer 76

Krabbe disease

Question 77

In what disease is there pathologic accumulation of glucocerebroside?

Answer 77

Gaucher disease

Question 78

In what disease is there pathologic accumulation of sphingomyelin?

Answer 78

Niemann-Pick disease

Question 79

In neurons, what is the length constant a measure of?

Answer 79

How far along an axon an electrical impulse can travel. This is decreased by demyelination.

Question 80

Injury to what nerve causes a trendelenburg gait?

Answer 80

Superior gluteal nerve.

Question 81

Autoantibodies against desmosomes in the skin causes what condition?

Answer 81

Pemphigus vulgaris

Question 82

Autoantibodies against hemidesmosomes causes what skin condition?

Answer 82

Bullous pemphigoid

Question 83

What are the function of desmosomes and hemidesmosomes respectively?

Answer 83

Desmosomes anchor cells to one another. Hemidesmosomes bind epithelial cells to the basement membrane below them.

Question 84

What are the histological findings of chronic bronchitis?

Answer 84

Thickened bronchial walls, lymphoctic infiltrate, mucus gland enlargement, and patchy squamous cell metaplasia.

Cigarette smoking is the leading cause.

Question 85

If a patient has gastric varices of the fundus, which vein do you expect to be occluded or have increased pressure?

Answer 85

The splenic vein as the short gastric veins that drain the fundus drain into the splenic vein. This can be seen in stuff like chronic pancreatitis or pancreatic/abdominal tumors.

Question 86

What enzyme does insulin signaling act thru in order to increase glycogen synthase?

Answer 86

A protein phosphatase that removes a P from glycogen synthase in order to activate it.

Question 87

Why does nitroprusside decrease both preload and afterload?

Answer 87

Because it is a balanced vasodilator and dilates both arteries and veins.

Question 88

What makes up an MHC class 1 molecule

Answer 88

A single heavy chain and a Beta2 microglobulin. Note, it is the heavy chain that has a high amount of variability to present diverse antigens.

Question 89

Where does the umbilical vein drain into? Via what structure?

Answer 89

It drains into the IVC of the fetus via the ductus venosus.

Question 90

What is the adult remnant of the umbilical vein?

Answer 90

The ligamentum teres.

Question 91

What is a Cheyne-Strokes breathing pattern? In which patients is it seen?

Answer 91

CSB is a cyclic breathing pattern in which apnea is followed by gradually increasing and then decreasing tidal volumes until the next apneic period. It is seen in pts w/ CHF.

Question 92

What chromosome and arm is the VHL gene on?

Answer 92

3p

Question 93

Why can patients with selective IgA deficiency have transfusion reactions?

Answer 93

Because they can form IgE against IgA that triggers uticaria, edema and wheezing upon receipt of blood products containing IgA.

Question 94

What are medications that are used to treat lead poisoning?

Answer 94

EDTA and dimercaprol

Question 95

In regards to K+ homeostasis in the nephron, which cells promote reabsorption of K+ at the collecting duct and which cells promote K+ secretion?

Answer 95

alpha-intercalated cells promote K+ resporption and principal cells promote K+ secretion.

Question 96

What causes annular pancreas?

Answer 96

It is where there is abnormal migration of the ventral bud of the pancreas. It causes it to encircle to duodenum and can lead to obstruction and pancreatitis, although many pts are asymptomatic.

Question 97

What are the last 2 vessels a thrombus traverses before lodging in the retinal artery and causing acute, painless, mono-ocular vision loss?

Answer 97

Internal carotid –> ophthalmic –> retinal

Question 98

What enzyme is the rate limiting step of bile acid salt synthesis from cholesterol? Name a medication that inhibits this enzyme.

Answer 98

Cholesterol 7alpha hydroxylase. Fibrates inhibit it.

Question 99

Heme synthesis has to occur in a couple areas of the RBC in order to happen completely. What are these two areas?

Answer 99

cytoplasm and mitochondria.

Mito needed for first step and final 3 steps.

Question 100

IL-4 promotes B cell isotype switching to what isotype?

Answer 100

IgE

Question 101

IL-5 promotes B cell isotype switching to what isotype?

Answer 101

IgA

Question 102

What is necessary in order to determine that a patient has the capacity to refuse treatment?

Answer 102

ability to express a choice, understand relevant medical info, appreciate consequences of treatment options, and offer a rationale for the decision.

Question 103

During what interval of fetal development does the yolk sac make RBCs?

Answer 103

weeks 3-8 of fetal development

Question 104

When do the liver and spleen make RBCs in fetal development?

Answer 104

Liver –> 6 weeks until birth

Spleen –> weeks 10-28 of fetal development

Question 105

What area of the anterior spinal cord does the artery of adamkiewicz supply?

Answer 105

The bottom 2/3. Usually starting around the level of T8.

Question 106

What are the lab findings in osteitis fibrosa cystica?

Answer 106

elevated Ca++, alk phos and PTH. Low levels of P. Results from chronic hyperparathyroidism.

Question 107

What is the most common cause of neonatal meningitis?

Answer 107

GBS (aka streptococcus agalactiae)

Question 108

What causes progressive multifocal leukoencephalopathy and what is seen on flair MRI?

Answer 108

JC virus. Non-enhancing areas of demyelination on MRI.

Question 109

In an upright person, ventilation _______ from the apex to the base?

Answer 109

Increases.

Question 110

What gene is mutated in ARPKD?

Answer 110

PHKD1 which codes for fibrocystin.

Question 111

Which artery is the middle meningeal artery a branch of?

Answer 111

Maxillary artery

Question 112

Why does silicosis place patients at increased risk for TB?

Answer 112

Because silica ingestion by macrophages disrupts their function and can even cause them to release viable mycobacteria.

Question 113

What is the mechanism of sirolimus?

Answer 113

It is a proliferation signal inhibitor that works by targeting the mTOR pathway. Specifically, it interupts IL-2 signal transduction. –> this prevents cell cycle progression and lymphocyte proliferation.

Question 114

What sort of dysfunction does dilated cardiomyopathy cause?

Answer 114

Systolic dysfunction. Causes HFrEF.

Question 115

What sort of dysfunction do restrictive cardiomyopathies cause?

Answer 115

diastolic dysfunction - HFpEF.

Question 116

What is transthyretin and what can it be a part of in terms of cardiac pathology?

Answer 116

It is a protein made by the liver that acts as a carrier of thyroxine and retinol. Mutations in it can cause it to misfold and become amyloid leading to deposition and restrictive heart failure.

Question 117

Why use glucocorticoids in a neonate that is experiencing NRDS?

Answer 117

Because corticosteroids promote surfactant production by accelerating the maturation of type II pneumocytes.

Question 118

What enzyme is deficient in PKU?

Answer 118

phenylalanine hydroxylase

Question 119

What are the brain findings on autopsy of PKU patients?

Answer 119

hypopigmentation of cholinergic brain centers which are the substantia nigra, the locus ceruleus, and the vagal nucleus dorsalis.

Question 120

What enzyme is most commonly depressed or absent in albinism?

Answer 120

Most commonly tyrosinase. This is because melanin synthesis relies on this enzyme.

Question 121

What is the mechanism of sirolimus?

Answer 121

It is a proliferation signal inhibitor that works by targeting the mTOR pathway. Specifically, it interupts IL-2 signal transduction.

Question 122

What is the mechanism of bortezomib?

Answer 122

Binds the 26S proteasome.

Question 123

What is the mechanism of mycophenolate?

Answer 123

It reversibly inhibits a critical step in de novo purine synthesis (inosine monophosphate dehydrogenase), which is required for proliferation of activated lymphocytes. Selectively targets lymphocytes, reducing B and T cell proliferations and antibody production while promoting T cell apoptosis.

Question 124

What causes a patent foramen ovale?

Answer 124

Incomplete fusion of the septum primum and secundum.

Question 125

What is the unique location and role of the H1 histone protein?

Answer 125

It is uniquely located in that it is on the outside of the protein core of histones. It binds the linker sections between nucleosomes to help package DNA into a more condensed structure.

Note: the core histones are H2A, H2B, H3 and H4.

Question 126

What auscultation finding is associated w/ PDA?

Answer 126

Continuous murmur heard best at the L sternal border.

Question 127

Under what conditions is pigment stone formation promoted in the gall bladder?

Answer 127

In instances of increased unconjugated bilirubin (hemolysis, secondary to infection by stuff like the helminth C. sinensis).

Question 128

True or false, Candida albicans is a germ-tube negative fungus.

Answer 128

False! It is a germ-tube positive fungus

Question 129

What serological markers are present during the window period of HBV infection?

Answer 129

Only anti-Hbe and anti-Hbc IgM are present.

Question 130

What are the first and second most common causes of impetigo?

Answer 130

First = S. aureus
Second = GAS.

Question 131

How does giardia infection lead to diarrhea?

Answer 131

It caused small bowel inflammation (loss of brunch border enzymes) and villous atrophy leading to malabsorption and atrophy.

Question 132

What is the first line treatment for pan-susceptible enterococcus infection?

Answer 132

ampicillin

Question 133

What are the HACEK organisms (those that cause culture negative endocarditis)?

Answer 133

Haemophilus spp., Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae.

Question 134

What media are typically used for growth and isolation of diptheria?

Answer 134

Typically Loeffler medium and tellurite agar are used in conjunction for the diagnosis of C. diptheriae infection.

Question 135

What agar is used to culture pertussis?

Answer 135

Bordet-Gengou agar is used to culture Bordetella pertussis. Regan-Lowe medium can be used too (this is more common today).

Question 136

What is pathognomonic on bronchoalveolar lavage for PJP injection?

Answer 136

foamy alveolar casts.

Question 137

In what direction is blood normally shunted in tetralogy of fallot?

Answer 137

R to L shunt

Question 138

What part of the brain initiates conjugate horizontal gaze?

Answer 138

The frontal eye field in the cerebral cortex.

Question 139

What causes an umbilical hernia?

Answer 139

Incomplete closure of the umbilical ring.

Question 140

Where in the CNS are seratonergic (seratonin releasing) neurons primarily found?

Answer 140

In the Raphe nuclei in the brainstem.

Question 141

Where is the locus ceruleus and what does it house?

Answer 141

It is in the dorsal pons and it houses the noradrenergic (norepi releasing neurons) that contribute to fight or flight response.

Question 142

What does the nucleus of Meynert house?

Answer 142

The cell bodies of acetylcholine releasing neurons.

Question 143

What is riboflavin (B2 vitamin) a precursor for? As such, what enzymatic reaction is is a cofactor in?

Answer 143

Precursor for FAD and FMN. FAD is a cofactor in the succinate dehydrogenase reaction in the TCA cycle.

Question 144

Histone acetylation ________ DNA transcription

Answer 144

enhances

Question 145

What pathogen should you be concerned for in a patient w/ liver cysts and a ton of exposure to dogs? What is the first line medical tx?

Answer 145

Echinococcus granulosus (a parasitic tapeworm transmitted by dog feces). Albendazole is medical therapy.

Question 146

What is the most common cause of pneumonia in CF pts under 20? Over 20?

Answer 146

< 20 –> S. aureus

> 20 –> pseudomonas

Question 147

What is a complication of CMV retinitis?

Answer 147

Retinal detachment

Question 148

Degeneration of the ________ hair cells in the organ of corti causes high frequency hearing loss (aka presbycusis) and degeneration of the _______ hair cells causes low frequency hearing loss?

Answer 148

Proximal hair cells –> high freq loss

Distal hair cells –> low freq loss

Question 149

Basal cell carcinoma is more commonly seen on the ______ lip, whereas squamous cell carcinomas are more commonly seen on the ______ lip.

Answer 149

Basal –> upper

Squamous –> lower

Question 150

What is the pre-malignant lesion for squamous cell carcinoma?

Answer 150

Actinic keratosis.

Question 151

What sort of diuretic medical management is indicated in an acute CHF exacerbation?

Answer 151

Furosemide

Question 152

What sort of kidney stones are hexagonal?

Answer 152

Cysteine stones (pts often have defects in amino acid resorption in the proximal tubule).

Question 153

Which H2 blocker used for tx of PUD can cause decreased libido and gynecomastia?

Answer 153

Cimetidine

Note that ranitidine has the same mechanism of action but lacks the anti-androgenergic side effects.

Question 154

What condition is temporal arteritis associated with?

Answer 154

Polymyalgia rheumatica

Question 155

What cardiac defect is Friedriech Ataxia associated with?

Answer 155

Hypertrophic cardiomyopathy

Question 156

Acute hemolytic transfusion reactions represent what type of hypersensitivity reaction?

Answer 156

Type II

Question 157

What mediators cause the vasodilation and shock sxs in acute hemolytic transfusion reaction? How about the cell lysis?

Answer 157

Shock –> C3a and C5a causing vasodilation

lysis –> C5b-C9

Question 158

What does the metyrapone stimulation test look at?

Answer 158

It tests the HPA axis by inhibiting cortisol production. As such, there is no feedback inhibition and there should be an expected ACTH surge if the axis is intact.

Question 159

Puncture of the femoral artery superior to the inguinal ligament is likely to lead to bleeding in what space?

Answer 159

The retroperitoneal space as the external iliac artery courses just inferior to the peritoneum.

Question 160

What molecule/signal activates mTOR to translocate to the nucleus? Which one inhibits mTOR?

Answer 160

Protein kinase B aka Akt activates mTOR

PTEN inhibits mTOR

Question 161

True or false, enterococcus is part of the normal urogenital flora?

Answer 161

True! Why manipulation of these areas (i.e. cytoscopy) can cause still like enterococcus endocarditis.

Question 162

What foramen is traversed as CSF moves from the lateral to third ventricle?

Answer 162

Interventricular foramina of monro

Question 163

In a pt w/ acute adrenal crisis that has been on long term GC therapy, what would you expect the CRH, ACTH and cortisol levels to be?

Answer 163

All would be low b/c the axis has been suppressed for so long and chronic GC use causes atrophy of the cells that produce each of these things.

Question 164

How strong is “prior attempt” as a risk factor for suicide?

Answer 164

Strong! In fact it is the strongest RF! Patients w/ a prior attempt are 5-6x more likely to attempt again.

Question 165

What is the clinical presentation of a patient w/ galactose-1-P uridyl transferase deficiency?

Answer 165

Jaundice, hepatomegaly, vomiting, renal dysfunction, E. coli sepsis, cataract, hemolytic anemia.

Question 166

In 5’ to 3’ direction, what are the 3 mRNA stop codons?

Answer 166

UAA, UAG and UGA

Question 167

What is a normal A-a gradient in healthy individuals?

Answer 167

5-15 mmHg

Question 168

What are the four major causes of hypoxemia (aka low PaO2)?

Answer 168

Alveolar hypoventilation, R to L shunt, diffusion impairment, V/Q mismatch.

Question 169

What is the presentation of I-cell disease?

Answer 169

course facial features, clouded corneas, restricted joint movement, high plasma levels of lysosomal enzymes,

Question 170

What is the mechanistic defect in I-cell disease?

Answer 170

Patients have a defect that prevents them from phosphorylating the mannose residues in the cis golgi of proteins that are destined for the lysosome. results in aberrant intercellular targeting of proteins.

Question 171

What vitamin is a cofactor for α-ketoglutarate dehydrogenase, pyruvate dehydrogenase, and transketolase?

Answer 171

Thiamine (B1)

Question 172

What is the most specific test w/ which to dx syphilis?

Answer 172

The fluorescent treponemal antibody absorption (FTA-ABS) test is the most specific serologic test for syphilis

Question 173

Where is oxytocin stored?

Answer 173

In the posterior pituitary! It is made in the hypothalamus but NOT stored there.

Question 174

What is the pathophysiology of globozoospermia?

Answer 174

The Golgi apparatus is not transformed into the acrosome, resulting in male infertility.

Question 175

What is a shared ADR of the anti-thyroid medications methimazole and propylthiouracil?

Answer 175

They both can cause agranulocytosis (presentation is commonly sudden onset fever and sore throat).

Question 176

What is the common presentation of acute intermittent porphyria?

Answer 176

Neuro sxs (tingling, difficulty concentrating), recurrent episodes of non-specific abdominal pain, port-colored wine.

Question 177

What is the treatment of acute intermittent prophyria? What enzyme does treatment down-regulate?

Answer 177

Infusion of hemin (a heme preparation). Down-regulates ALA-synthase.

Question 178

Of cellular swelling, mitochondrial vacuolization, and nuclear shrinkage (pyknosis), fragmentation and dissolution, which is considered reversible cell injury?

Answer 178

Cellular swelling. The other two are (mito and nuclear changes) are considered irreversible cell injury.

Question 179

What innervates the cricothyroid muscle?

Answer 179

External branch of the laryngeal nerve

Question 180

What does the cricothyroid muscle do?

Answer 180

It acts to tense the vocal cords. Denervation may cause a low, hoarse voice.

Question 181

What defines isolated systolic hypertension (ISH)? What causes it?

Answer 181

ISH = systolic BP > 140 w/ diastolic BP < 90.

It is caused by age related stiffness and decrease in compliance of the aorta and major peripheral vessels.

Question 182

What embryologic layer is the spleen derived from?

Answer 182

Mesoderm. This is unique b/c most of the rest of the GI tract (liver, pancreas, intestines, etc.) are derived from endoderm.

Question 183

What is PD-1 and what is its relation to cancer evasion of the immune system?

Answer 183

PD1 is programmed death (receptor or ligand) 1. The receptor version is on T cells and when the ligand binds, this down-regulates the immune response such that T cells don’t kill the cells. Thus, cancers evade the immune system by up-regulating the PD1 ligand to avoid being killed. There are anti-PD1 monoclonal antibody therapies that can be used in some cancers to get around this.

Question 184

Why can injury to the facial nerve cause ear pain?

Answer 184

B/c a branch of this nerve innervates the stapedius muscle which helps stabilize the stapes. W/o it there is wider oscillation that can cause hyperacusis and pain.

Question 185

What is the initial step in the pathogenesis of atherosclerosis?

Answer 185

Endothelial cell injury –> this leads to increased permeability and monocyte and lymphocyte adhesion and invasion.

Question 186

What is pulsus paradoxus?

Answer 186

It is where there is a decrease in systolic BP > 10 mmHg upon inspiration.

Question 187

For which cardiac pathology is this murmur classic for: opening snap followed by a diastolic rumbling murmur?

Answer 187

mitral stenosis

Question 188

What is the Hawthorne effect?

Answer 188

The tendency of study subjects to change their behavior once they know that they are being observed.

Question 189

What is Berkson’s bias?

Answer 189

Selection bias created by choosing hospitalized patients as the control group.

Question 190

What is the Pygmalion effect?

Answer 190

Where the researchers’ belief in the efficacy of a treatment can potentially affect the outcome (i.e. teachers artificially being told students had higher IQs and these students ending up performing better).

Question 191

What is the equation for half-life that uses clearance (CL) and volume of distribution (Vd)?

Answer 191

T1/2 = (0.7 x Vd) / CL

Question 192

How does biotin (vitamin B7) deficiency present and who is it seen in (it’s a rare deficiency)?

Answer 192

Presentation is non-specific –> myalgias, rash including macular dermatitis, changes in mental status and anorexia.

Seen in people with poor diets, with excessive raw white egg consumption (there is a biotin binding factor) and in rare congenital disorders of metabolism.

Question 193

What are the first set of LNs that the superficial lateral lymph tract drain to in the leg? How about the medial tract?

Answer 193

Lateral tract –> popliteal nodes first and then the deep inguinal nodes.

Medial tract –> straight to the inguinal LNs.

Question 194

What is the characteristic presentation of Wiskott-Aldrich syndrome?

Answer 194

Recurrent pyogenic infections in the context of low serum IgM levels, a pruritic rash, and thrombocytopenia are characteristic of Wiskott-Aldrich syndrome.

Question 195

What is the calculation for loading dose (LD)?

Answer 195

LD = (desired plasma concentration) × (volume of distribution / bioavailability)

Question 196

What are some signs of kernicterus in a baby?

Answer 196

Neurological sxs like hypotonia, poor reflexes and lethargy.

Question 197

What binds unconjugated bilirubin in the blood?

Answer 197

Albumin

Question 198

What is the name of the rash that accompanies fifth disease? What is the infectious agent?

Answer 198

Erythema infectiosum (the one with the slapped cheek appearance). Caused by parvovirus B19.

Question 199

In addition to appearing as spherules with endospores, what is another way that coccidiodes can appear?

Answer 199

Barrel-shaped arthroconidia and 90-degree branching pattern

Question 200

What is the issue/metabolism inability of Hunter and Hurler syndrome?

Answer 200

An inability to breakdown glycosoaminoglycans.

Question 201

What causes Niemann-Pick disease? What is the presentation of type A disease?

Answer 201

An inherited deficiency of sphingomyelinase. Type A presents in infancy with progressive neurologic deterioration and hepatosplenomegaly.

Question 202

What is the function of IL-8?

Answer 202

Neutrophil chemotaxis and activation. It is secreted by macrophages and T cells.

Question 203

What sort of congenital anomaly is holoprosencephaly an example of?

Answer 203

Developmental Field Defect

Question 204

What is responsible for the green color of pus and sputum from pneumonia?

Answer 204

Myeloperoxidase from neutrophils.

Question 205

In general, what do most states require (or not require) in terms of parental notification or consent for abortion?

Answer 205

2/3 of states require consent while the other 1/3 requires notification.

Question 206

Which pituitary cells can be classified as acidophils and which can be classified as basophils?

Answer 206

Acidophils –> GH and PRL secreting cells

Basophils –> FSH, LH, TSH and ACTH secreting cells

Question 207

What is the pathophysiology of Hartnup disease? As such, how may it present?

Answer 207

In Hartnup disease the renal and enterocyte transporter of neutral amino acids is defective. As such, patients have increased tryptophan in the urine and less absorption from the GI tract. This leads to lack of tryptophan which is a precursor for B3 (niacin) and the deficiency causes pellagra sxs.

Question 208

What tumor is associated w/ “jelly belly” (an abdomen full of mucus)?

Answer 208

Pseudomyxoma peritonei

Question 209

In male embryogenesis, which cell secretes anti-mullerian factor?

Answer 209

Sertoli cell

Question 210

Which cranial nerve innervates the muscles of mastication?

Answer 210

CN V3

Question 211

For what pathogen do you use a calcium-alginate swab to get a culture from the pharynx?

Answer 211

Pertussis as you can’t swab it well w/ a cotton swab.

Question 212

Where do sperm acquire motility and what sort of epithelium is this tissue lined with?

Answer 212

Sperm acquire motility in the epididymis, which is lined with a layer of pseudostratified columnar epithelium with stereocilia.

Question 213

What does a muscle bx of dermatomyositis show?

Answer 213

Infiltration of CD4+ T lymphocytes in the perimysium of muscle tissue.

Question 214

What does a muscle bx of polymyositis show?

Answer 214

Transfascicular and intracellular CD8+ mediated inflammation.

Question 215

What is the best medication to use to treat hyperthyroidism during pregnancy?

Answer 215

Propylthiouracil (PTU) is preferred during the first trimester of pregnancy b/c methimizole use during this time is associated w/ congenital malformations.

Question 216

Of placenta previa and placenta abrupto, which has painful bleeding?

Answer 216

Abrupto. Previa it is painless bleeding.

Question 217

What are the 10 essential amino acids?

Answer 217

A mnemonic for remembering all 10 essential amino acids is PVT TIM HALL (PriVaTe TIM HALL): Phenylalanine, Valine, Threonine, Tryptophan, Isoleucine, Methionine, Histidine, Arginine, Leucine, Lysine.

Question 218

How would you describe the C2 dermatome?

Answer 218

It is like the posterior half of a skull cap. It’s basically the top back of the head.

Question 219

How does inspiration affect blood flow to the heart?

Answer 219

Inspiration increases blood flow to the right heart.

Question 220

How does squatting affect blood flow?

Answer 220

It increases preload and afterload.

Question 221

True or false, IL-6 is associated w/ increasing production of acute phase reactants?

Answer 221

True!

Question 222

Name 4 muscles that the radial nerve innervates which are affected in a “wrist drop” injury?

Answer 222

The radial nerve innervates the Brachioradialis, Extensors of the wrist and fingers, Supinator, and Triceps (“radial nerve innervates the BEST”).

Question 223

How does the IVC pass through the diaphragm?

Answer 223

It passes through the central tendon of the diaphragm.

Question 224

How does the aorta pass through the diaphragm and into the abdominal cavity?

Answer 224

It enters by traversing under the median arcuate ligament.

Question 225

What travels with the vagus nerve will passing through the diaphragm?

Answer 225

The esophagus

Question 226

What is the secondary messenger that increases when alpha 1 adrenergic receptors are stimulated?

Answer 226

IP3 increases

Question 227

What is the difference between lead time bias and length time bias?

Answer 227

Lead time bias is where using a screening test creates an apparent increase in survival time in patients due to earlier detection but there is actually no change in prognosis (overall time from disease onset to time of death is unchanged).

Length time bias is the phenomenon where really aggressive forms of a disease are less likely to be detected on screening because they progress so rapidly and thus are more likely to be missed compared to more indolent forms of the disease.

Question 228

The finding of pancreatic acini in a Meckel diverticulum is an example of _____?

Answer 228

Ectopy, which is the microscopic finding of functionally normal cells/tissue in an abnormal location due to embryological maldevelopment.

Question 229

The ______ is the region of the LN populated mainly by T lymphocytes and dendritic cells.

Answer 229

paracortex

Question 230

What do ADH, ACTH, epinephrine and glucagon have in common?

Answer 230

They all work by binding to G protein coupled receptors.

Question 231

What sort of amino acids bind to Zn ions in Zn finger motifs

Answer 231

Cysteine and sometimes histadine

Question 232

What is the enzyme that catalyzes the conversion of angiotensin I to angiotensin II and where is primarily found?

Answer 232

Angiotensin converting enzyme. Founds primarily w/in small pulmonary vessels and endothelial bound angiotensin converting enzyme.

Question 233

What does renin do in terms of angiotensin?

Answer 233

It converts angiotensinogen into angiotensin I.

Question 234

What organ produces angiotensinogen?

Answer 234

The liver

Question 235

Name 2 actions of angiotensin II

Answer 235

1 = potent vasoconstrictor which raises SVR and thus BP and afterload.

2 = stimulates the adrenal gland to make aldosterone.

Question 236

In terms of cardiac catheterization, what is normal pressure for the...
Right atrium?
Right ventricle?
Pulmonary artery?
PCWP (aka L atrium)?

Answer 236

Right atrium –> 1-6 mmHg

Right ventricle –> diastolic is just below the RA pressure and systolic is 15-30 mmHg. There is a pulsatile waveform.

Pulm artery –> same systolic pressure as RV w/ increase in diastolic pressure on waveform to 6-12 mmHg

PCWP –> 6-12 mmHg (usually equal to diastolic pressure of pulm artery).

Question 237

Where are the renin secreting juxtaglomerular cells located?

Answer 237

In the tunica media of the afferent arterioles of the kidney.

Question 238

Where it the macula densa located and what is its function?

Answer 238

Located in the distal convoluted tubule and acts as a Na+ sensor.

Question 239

What sort of sensation are Meissner corpuscles responsible for?

Answer 239

Light discriminatory touch

Question 240

What sorts of sensation are Paciniain corpuscles responsible for?

Answer 240

These receptors are mainly involved in perception of pressure, coarse touch, high-frequency vibration, and tension. They are commonly damaged in diabetic neuropathy.

Question 241

Through what vessels do the ulnar and radial arteries usually anastamose?

Answer 241

The superficial and deep palmar arches.

The superficial arch is a continuation of the ulnar artery and usually anastomoses with branches of the radial artery, whereas the deep arch is a continuation of the radial artery that forms anastomoses with branches of the ulnar artery.

Question 242

What is the function of infraspinatus?

Answer 242

Lateral rotation of the arm.

Question 243

What is the function of supraspinatus?

Answer 243

It abducts the arm initially prior to assistance from the deltoid muscle.

Question 244

What is the function of subscapularis?

Answer 244

Adducts and medially rotates the arm

Question 245

Which nerves innervate the psoas and iliacus muscles?

Answer 245

The psoas muscle is innervated by the lumbar plexus, and the iliacus muscle is innervated by the femoral nerve.

Question 246

The inferior gluteal nerve innervates the?

Answer 246

Gluteus maximus muscle

Question 247

The superior gluteal nerve innervates the?

Answer 247

Gluteus medius and minimus muscles

Question 248

What is the most common rotator cuff injury?

Answer 248

Injury to the supraspinatus tendon

Question 249

Damage to what nerve is suggested by weakness in the following actions:

• Wrist extension?
• Wrist flexion?
• Pronation of the forearm?

Answer 249

Wrist extension –> radial nerve injury

Wrist flexion –> ulnar and/or median nerve injury

Pronation –> median nerve injury

Question 250

What does the infundibulopelvic ligament (aka the suspensory ligament) connect and what does it contain?

Answer 250

Connects the ovaries to the lateral pelvic wall and contains the ovarian vessels.

Question 251

What causes intestinal atresia of the midgut (jejunum, ileum and proximal colon)?

Answer 251

Vascular occlusion in utero

Question 252

What are the findings of midgut intestinal atresia?

Answer 252

Proximal segment ending in a blind pouch followed by a missing segment and then a distal segment of ileum that assumes a spiral configuration around an ileocolic vessel. –> this specific pattern is known as “apple-peel” atresia and is indicative of SMA infarction in utero.

Question 253

Trachea-esophageal fistula is an embryonic failure of _____?

Answer 253

failure of partitioning.

Question 254

What is the most common genetic defect causing homocysteinuria?

Answer 254

Autosomal recessive mutation that causes cystathione synthase deficiency.

Question 255

Why is it beneficial to give a patient who lacks IL-12 receptors INF-gamma?

Answer 255

Because helper T cells signaled by IL-12 differentiate into TH1 subtype T cells and these secrete INF-gamma that is required for macrophage activation to occur.

Question 256

What it the chemical that induces helper T cells to become the TH2 subtype?

Answer 256

IL-4

Question 257

Describe differences in terms of immune function between TH1 and TH2 cells?

Answer 257

TH1 activate macrophages and cytotoxic T cells leading to cellular immunity. They’re responsible for delayed type hypersensitivity reactions. TH2 activate B cells and promote class switching leading to humoral immunity.

Question 258

What are the two types of sweat glands, what is their stimulus and where are they located?

Answer 258

Eccrine glands (located all over the skin) secrete a watery solution and are stimulated by direct sympathetic innervation. Apocrine glands (axillae, groin, areola, genitals and anus), which secrete oily, viscous fluid, are stimulated by catecholamines.

Question 259

What is the pathological embryological failure that occurs in diaphragmatic hernia?

Answer 259

Failure of the pleuroperitoneal canal to close completely,

Question 260

Which side of the ankle is the deltoid ligament on?

Answer 260

The medial ankle

Question 261

What ligament is most commonly injured in ankle sprains?

Answer 261

Anterior talofibular ligament.

Question 262

What is the function of the cricothyroid muscle?

Answer 262

This muscle serves to increase pitch by tilting the anterior part of the thyroid cartilage forward and stretching the vocal folds.

Question 263

What is the muscle that is torn when there is a perineal tear during child delivery that produces fecal incontinence post-birth?

Answer 263

The anal sphincter

Question 264

What is the chemotherapeutic regimen used to treat Hodgkin lymphoma?

Answer 264

ABVD regimen –> adriamycin (doxorubicin), bleomycin, vinblastine, and dacarbazine.

Question 265

Why is sodium thiosulfate administered alongside sodium nitroprusside used in management of malignant hypertension?

Answer 265

Because metabolism of nitroprusside can lead to cyanide formation and this helps prevent that.

Question 266

what embryonic layer do microglia come from?

Answer 266

Mesoderm

Question 267

Anti-smith and anti-dsDNA antibodies are specific for what condition?

Answer 267

SLE

Question 268

At what point in salicylate overdose does metabolic acidosis occur? What happens before this?

Answer 268

About 12 hours after ingestion. Before that the drug induces a respiratory alkalosis.

Question 269

What does the the CAAT and TATA box both do? Where in the gene are they located?

Answer 269

They act as promoters for initiation of transcription by acting as binding sites for RNA polymerase II and transcription factors.

CAAT is about 75 bp upstream from start of transcription and TATA is about 25bp upstream from start.

Question 270

Describe an ecological study?

Answer 270

It is where the frequency of a given characteristic (i.e. vitamin D intake) and a given outcome (i.e. MS) are studied using population data.

Sounds like it is basically a cross-sectional study but uses population data as opposed to individual data.

Question 271

What are the changes that account for the unchanged TLC, decreased FVC and increased RV on LFTs in older people?

Answer 271

There is a decrease in elastic recoil due to lose of alveolar elasticity w/ aging. However, there is also decreased chest wall compliance due to osteoporosis and stiffening from rib calcification. As such, TLC stays unchanged (the above changes couneract). Due to collapse of supporting tissues around the airways there is increased RV. As RV is a higher proportion of TLC, this causes FVC to decrease.

Question 272

What does the metanephric mesoderm (aka the metanephric blastema) give rise to?

Answer 272

Glomeruli, Bowman’s capsule, proximal tubules, loop of henle and distal convuluted tubules.

Question 273

What is the maintenence dose equation?

Answer 273

MD/Tau (dosing interval) = Cpss x CL

Question 274

What is the loading dose equation?

Answer 274

LD = Vd x Cp

Question 275

Where are B1 receptors found?

Answer 275

Cardiac tissue and renal juxtaglomerular cells

Question 276

What is the physiology w/ which capsaicin treats pain in stuff like postherpetic neuralgia?

Answer 276

It causes release and subsequent depletion of substance P. Thus it may initially be painful to use but once depletion occurs there is analgesia.

It also activates TRPV1 receptors and this causes dysfunctionalization of nociceptive fibers.

Question 277

Where do endorphins and dynorphins act in the opioid system to cause pain relief?

Answer 277

On the mu and kappa opioid receptors respectively.

Question 278

How does a musculocutaneous nerve injury present?

Answer 278

Loss of forearm flexion, supination, and loss of sensation to the laternal forearm.

Question 279

On what chromosome is genetic defect in NF-2?

Answer 279

NF-2 = chromosome 22. NF-1 is chromosome 17.

Question 280

What does the obturator nerve innervate?

Answer 280

The adductor muscles in the median compartment of the thigh.

Question 281

Through what space does the facial nerve exit the skull?

Answer 281

Through the stylomastoid foramen.

Question 282

Where are hepatic stellate cells located in the liver? What is a vitamin that they exclusively store (are the only cell to do so)?

Answer 282

Location = space of Disse

Vitamin = Vitamin A.

Question 283

Describe the borders of the femoral triangle

Answer 283

It is a subfascial space bounded superiorly by the inguinal ligament, medially by the adductor longus muscle, and laterally by the sartorius muscle.

Question 284

What produces ADH?

Answer 284

The supraoptic nucleus of the hypothalamus.

Question 285

What is the timeframe of onset for hyperacute, acute and chronic transplant rejection? And the mechanism?

Answer 285

Hyperacute –> w/in minutes due to pre-existing recipient antibodies against donor antigen.

Acute –> Weeks to months. CD8+ T cells attack donor MHC molecules. Can also get humoral response but the antibodies develop after receiving the organ.

Chronic –> Weeks to months due to CD4+ cells responding to recipient antigen presenting cells presenting donor peptides.

Question 286

What is the clinical presentation of patients with essential thrombocythemia?

Answer 286

Patients exhibit epistaxis, thrombosis, bruising, bleeding, and mild splenomegaly. Patients may also complain of erythromelalgia (burning and redness of the hands and feet due to platelets obstructing blood flow in capillaries and arterioles).

Question 287

Where is type II collagen found?

Answer 287

Cartilage, vitreous body, nucleus propulsus.

Question 288

What protein is overexpressed in Burkitt lymphoma? Follicular?

Answer 288

Burkitt –> C-Myc

Follicular –> BCL-2

Question 289

What is deficient in Hunter syndrome and what does this cause accumulation of?

Answer 289

It is caused by a deficiency in iduronate sulfatase, leading to accumulation of the mucopolysaccharides dermatan and heparan sulfate in affected tissues.

Question 290

What sort of pathogen is Haemophilus ducreyi? How does it present?

Answer 290

Gram-negative coccobacillus. Presents as a painful ulcer with an erythematous base that bleeds easily when manipulated. Unilateral inguinal lymphadenopathy may be seen.

Question 291

How many days after fertilization does the oocyte divide in order to get mo/di monozygotic twins?

Answer 291

Between 4-8 days after fertilization.

Question 292

What is rubeola another word for?

Answer 292

Measles

Question 293

What pattern of liver injury is seen in acetominophen overdose?

Answer 293

Centrilobar necrosis (aka zone 3 damage). This occurs b/x this area has the highest amount of enzymes that are metabolizing drug to toxic byproduct, low levels of glutathione (which is protective), and is least oxygenated..

Question 294

What causes zone I (periportal) liver damage?

Answer 294

Affected first by viral hepatitis. Also affected by toxins like cocaine.

Question 295

What causes zone II (intermmediate zone) liver damage?

Answer 295

Yellow fever.

Question 296

Which class of antibiotics disrupts protein synthesis by blocking translocation?

Answer 296

The macrolides (they bind to the 23s rRNA on the 50S ribosomal subunit).

Question 297

What is the tx for De Quervian (aka subacute granulomatous thyroiditis)?

Answer 297

No tx! It is a hypothyroid state following a viral illness and it generally resolves to euthyroid state w/o tx.

PE is notable for an exquisitely tender thyroid gland.

Question 298

True or false, a living will supersedes a durable power of attorney for medical decisions?

Answer 298

FALSE! It is in fact the opposite and a durable power of attorney supersedes even a living will.

Question 299

What is the pathophysiology of osteopetrosis?

Answer 299

Failure of bone remodeling and resorption secondary to defect in osteoclasts. This disorder presents with pancytopenia, anemia, and compression of cranial nerves from bony overgrowth.

The autosomal recessive form is aggressive and usually lethal in utero or neonatal period. AD form is more subtle.

Question 300

What is alkaptonuria?

Answer 300

Alkaptonuria is an autosomal recessive disease caused by a deficiency of homogentisic acid oxidase, an enzyme in the tyrosine degradation pathway that converts homogentisic acid to maleylacetoacetic acid. In this disease, homogentisic acid builds up in the tissue and is excreted in the urine, and exposure to alkali or oxygen results in the characteristic change of the urine color to dark black.

Patients with this often will develop arthritis.

Question 301

What are the derivatives of the ventral pancreatic bud?

Answer 301

The proximal portion of the main pancreatic duct and the uncinate process (a small portion of the pancreatic head).

Question 302

What are the derivatives of the dorsal pancreatic bud?

Answer 302

Pancreatic tail, body, most of the head, and the small accessory pancreatic duct.

Question 303

What is the case-fatality rate?

Answer 303

Proportion of reported cases of a condition or disease that are fatal within the population affected by the condition or disease over time.

Question 304

What are the metabolic effects of thiazides?

Answer 304

Raise LDL cholesterol and triglycerides. They also decrease the secretion of insulin and reduce the uptake of glucose in peripheral tissues.

Question 305

What is the difference between factitious disorder and malingering?

Answer 305

In factitous disorder the falsification or inducement of sxs is done in order to assume the sick role. In malingering falsification or exaggeration of sxs is done to obtain external incentives (secondary gain).

Question 306

Why can admin of mu opioid potentially lead to biliary colic?

Answer 306

Because they have a rare adverse rxn where they cause smooth muscle contraction in the sphincter of oddi. This increases common bile duct pressure and can even lead to biliary colic.

Question 307

What is the action of opioids at the pre-synaptic neuron by binding to mu receptors? How about at the post-synaptic neuron?

Answer 307

Pre-synaptic –> closure of voltage gated Ca channels which reduces release of excitatory NT release (stuff like ACh, substance P, etc.)

Post-synaptic –> Lead to K+ efflux out of the cell on the post-synaptic side causing hyper-polarization.

Question 308

Why are the testes small in Klinefelter syndrome?

Answer 308

There is progressive destruction and hyalinization of the seminephrous tubules.

Question 309

What does cryoprecipitate contain?

Answer 309

Only cold soluble proteins which are factor VIII, fibrinogen, VW factor and vitronectin

Question 310

What is the defect in familial hypocalciuric hypercalcemia (FHH)? Name the class of the specific protein that is mutated.

Answer 310

in FHH there is a defect in the calcium sensing receptors that are responsible for sensing calcium and down-regulating PTH secretion when levels are too high. These receptors and G protein coupled receptors. The defect causes sensing to not occur as well such that higher levels of Ca++ are needed to suppress PTH secretion. This leads to high PTH levels.

Question 311

Name 3 hormones that work through the JAK-STAT pathway.

Answer 311

GH, PRL and erythropoietin

Question 312

What does deficiency in aldolase B cause? What accumulates?

Answer 312

Heriditary fructose intolerance. Fructose 1-Phosphate accumulates.

Question 313

What is prosopagnosia? Infarct to what area of the brain causes it?

Answer 313

Inability to recognize faces. It is most often caused by a lesion in the right inferior temporal lobe, specifically the right fusiform gyrus.

Question 314

What are the typical cancers seen in Li-Fraumeni syndrome?

Answer 314

Typical cancers include osteosarcomas, soft tissue sarcomas, early-onset breast cancers, adrenocortical tumors, and leukemias

Question 315

What does cystathione deficiency cause?

Answer 315

Homocystinuria

Question 316

Where do the initial steps of the urea cycle, converting NH3 to urea, occur?

Answer 316

In the mitochondria of hepatocytes.

Question 317

What are the first two steps of the urea cycle?

Answer 317

First is the convergence of ammonia and carbon dioxide to form carbamoyl phosphate (done by carbomyl phosphate synthetase I). Next is the convergence of carbamoyl phosphate and ornithine to form citrulline (done by ornithine transcarbamylase).

Question 318

What does Western blot detect? How about Northern blot? Southern blot?

Answer 318

• Western detects protein (i.e. HIV proteins for HIV testing)
• Northern blot detects RNA via DNA/RNA hybridization.
• Southern blot detects DNA by DNA/DNA hybridization.

Question 319

Decreased maternal serum AFP and increased fetal nuchal translucency on US suggest what?

Answer 319

Trisomy 21

Question 320

Why is memantine a drug that can be used in the treatment of Alzheimer’s?

Answer 320

Memantine is an NMDA receptor antagonist and it helps b/c it is thought that CNS NMDA receptor overstimulation by glutamate may contribute to disease sxs.

Question 321

What encapsulates the median nerve in the “carpal tunnel?”

Answer 321

The transverse carpal ligament (flexor retinaculum) and the carpal bones more deeply.

Question 322

What conditions is carpal tunnel syndrome associated with?

Answer 322

Pregnancy, hypothyroidism, DM, rheumatoid arthritis and long hx of hemodialysis. These things reduce carpal tunnel space (through deposition of stuff).

Question 323

Why is H2PO4- increased in the urine in DKA?

Answer 323

Because in order to deal w/ the increased excretion of acid, the kidney increases excretion of buffers (like H2PO4) into the urine in order to buffer the increased acid.

Question 324

What are the two major buffers of acid in urine?

Answer 324

NH3 and H2PO4-

Question 325

Why does neutrophil count increase in the differential of WBC after admin of corticosteroids?

Answer 325

B/c the drug causes demargination of neuts that were previously attached to the vessel wall and this increases the count. This also accounts for why people are at increased risk for infection as there is now decreased neuts in tissue to fight stuff off.

W/ these meds there is also a decreased monocyte, eosinophil, basophil and lymphocyte count.

Question 326

Where is IGF-1 made?

Answer 326

In the liver.

Question 327

What are the positive and negative regulators of phosphofructokinase in glycolysis?

Answer 327

Positive –> AMP, fructose 2-6 bisphosphate

Negative –> citrate, ATP

Question 328

What type of GPCR are histamine1 and vasopressin1 receptors?

Answer 328

Gq

Question 329

The vascular variant of Ethers-Danlos is associated with a defect in what?

Answer 329

Type III Procollagen

Question 330

What is mutated in epidermolysis bullosa

Answer 330

Keratin 5 or keratin 14, the two major keratins in basal epithelial cells.

Question 331

What are the essential fatty acids?

Answer 331

linoleic and linolenic acid.

Question 332

What enzyme is deficient in benign fructosuria and why is it benign?

Answer 332

Fructokinase. It is benign because this enzyme converts fructose to fructose-1-P so if it is absent there is no metabolism of fructose in hepatocytes and no depletion of the cells’ phosphate supply.

Question 333

ST elevation in what ECG leads indicate acute occlusion of the right coronary artery?

Answer 333

II, III and aVF

Question 334

In addition to HIV tx what is an immune modulating medication that can be used for Kaposi’s sarcoma?

Answer 334

a-interferon (aka a2b interferon). It has anti-tumor properties by activating various aspects of the immune system.

Question 335

What is the initial testing for HIV?

Answer 335

The initial testing for HIV is done with an antigen/antibody combination immunoassay that detects HIV-1 and HIV-2 antibodies and the HIV-1 p24 antigen

Question 336

When clamping the uterine arteries during a hysterectomy, what structure must you take care not to harm due to its close proximity?

Answer 336

The ureters.

Question 337

True or false, Gonorrhea is a reportable infection in all 50 states?

Answer 337

True!

Question 338

Which LNs do the ovaries drain to first?

Answer 338

The para-aortic LNs

Question 339

How long must chronic depressed mood be present in order to make a dx of persistent depressive disorder (dysthymia)?

Answer 339

At least 2 years.

Question 340

What sort of antibodies does vaccination against N. meningitidis provide?

Answer 340

Capsular polysaccharide antibodies. I think the exception is the vaccine against the B subtype which has only recently been introduced.

Question 341

What is the difference between unfractionated heparin and LMWH like enoxaparin?

Answer 341

Both can inactivate factor Xa whereas only UFH inactivates thrombin too.

Question 342

What type of drug is fondaparinux?

Answer 342

It is a direct factor Xa inhibitor.

Question 343

Why can mycoplasma pneumoniae cause anemia?

Answer 343

Because you can get IgM antibodies that cross react w/ erythrocyte cell membranes. These are called cold agglutinins and can cause a hemolytic anemia.

Question 344

What causes release of BNP? What does it do?

Answer 344

BNP is released by the ventricles in response to stretch (volume overload). It (along w/ ANP) causes decreased BP, diuresis/natriuresis and vasodilation.

Question 345

What does rasburicase do and when would you administer it?

Answer 345

Rasburicase is the recombinant version of urate oxidase. It converts uric acid into allantoin which is 5-10x more soluble. It is administered prior to and during chemo tx to prevent tumor lysis syndrome. It specifically helps prevent the hyperuricemia and renal manifestations of TLS.

Question 346

What is the difference between an UMN lesion of CN7 and a LMN lesion of CN7?

Answer 346

An upper motor neuron lesion of the facial nerve (CN VII) would result in paralysis of the ipsilateral face with forehead sparing. The patient can raise his eyebrows or close his eyelids tightly, due to dual innervation from the contralateral facial nerve nucleus.

Conversely, a LMN lesion would not have forehead sparing.

Question 347

Name what the following are markers for:
CD27?
CD56?
CD34?

Answer 347

CD27 –> plasma cells
CD56 –> NK cells
CD34 –> fibrocytes

Question 348

What is the prominent mediator of acute rejection of trasnplant organs?

Answer 348

Acute transplant rejection is predominantly mediated by cytotoxic T lymphocytes (CD8), leading to cytotoxic graft cell death and release of proinflammatory cytokines.

Note that there can also be humoral forms of acute rejection which involve B cells and a neutrophilic infiltrate as opposed to the lymphocytic infiltrate seen w/ the above.

Question 349

How does hereditary orotic aciduria present? What enzyme deficiencies cause it?

Answer 349

Symptoms include poor growth, megaloblastic anemia, and orate crystals in urine.

Deficiency of Orotate phosphoribosyltransferase or orotidine 5′-monophosphate decarboxylase cause it.

Question 350

How does galactokinase deficiency present?

Answer 350

With galactosuria, galactosemia and can get infantile cataracts from accumulation of galactitol.

Question 351

What is the one K+ sparing diuretic that is not in the sulfa category?

Answer 351

Ethcrynic acid

Question 352

Where are the inhibitory neurons lost in achalasia (like what tissue layer)?

Answer 352

Loss of inhibitory neurons at he Auerbach plexus aka the myenteric plexus.

Question 353

True or false, you can microalbuminuria (30-300mg/day of loss) on a urine dipstick?

Answer 353

False! Microalbuminuria may indicate nephropathy in DM pts.

Question 354

How does DM nephropathy present on microscopy?

Answer 354

Glomerular basement membrane thickening and increased mesangial matrix deposition.

Question 355

What are the inferior pancreaticoduodenal arteries a branch of?

Answer 355

The superior mesenteric artery.

Question 356

Erb’s palsy results from damage to which brachial plexus trunk? What are the rami that feed into it?

Answer 356

Damage to the upper trunk which is fed by C5-C6 ventral rami

Question 357

Infection w/ ______ causes itching and serpiginous burrows in the webspace of hands and feet.

Answer 357

Scabies

Question 358

Why do the lesions of psoriasis become less severe during summer?

Answer 358

Because exposure to UV light is therapeutic for psoriasis.

Question 359

What does it mean to see parakeratosis?

Answer 359

It means that on histo of tissue including skin, there are nuclei still in the stratum corneum, which is abnormal.

Question 360

What pathogen is classically described as having a spaghetti and meatballs appearance on KOH prep? What does it cause?

Answer 360

Malassezia furfur causing tenea versicolor (patients have areas of hypo or hyperpigmentation).

Question 361

What is permethrin cream used to treat?

Answer 361

Scabies

Question 362

What is a keratoacanthoma?

Answer 362

A variant of squamous cell carcinoma that grows rapidly over the matter of weeks. It may regress spontaneously.

Question 363

What is the name for, and first line tx of, the rash that looks like acne but lacks comedones and may be associated w/ facial flushing in response to external stimuli like alcohol and heat.

Answer 363

Rosecea = the rash.

First line tx = tetracyclines or topical metronidazole.

Question 364

Distinguish seborrheic dermatitis from scalp psoriasis.

Answer 364

In seborrheic derm there are usually flat patches of erythema and scale w/ lesions usually confined to the hairline. Conversely, in scalp psoriasis has raised plaques that may involve beyond the hairline and hair loss is more likely to occur (but really only does so in severe cases).

Question 365

Atopic dermatitis is another name for _____? Where is the rash commonly seen?

Answer 365

Eczema. Rash is typically seen on flexural surfaces like the antecubital fossa. Can be seen on babies’ faces during infancy.

Question 366

How does the rash of livedo reticularis present?

Answer 366

Resembles a net w/ clear sections btwn the affected lines. Non-blanching. Honestly to me it looks like mottling but less purple and more red.

Question 367

How does the rash of necrobiosis lipoidica present and who does it commonly affect?

Answer 367

Presentation: reddish-brown plaques that progressively become more yellow, shiny and atrophic in appearance.

Typically affects the shins of insulin dependent diabetics.

Question 368

How does parvovirus B19 present in adults?

Answer 368

A lacy erythematous rash with rheumatoid-arthritis like arthropathy. The rash is morbilliform. It can cause hydrops fetalis when it occurs in pregnant women.

Question 369

What is pulsus paradoxus?

Answer 369

A drop is systolic BP that is greater than 10 mmHg on inspiration.

Question 370

What is the primary treatment for an acute COPD exacerbation?

Answer 370

Inhaled beta-agonists.

Question 371

What are the most frequent causes of pulsus paradoxus in the absence of pericardial disease?

Answer 371

COPD and asthma.

Question 372

Opiate action at which receptor causes respiratory and cardiac depression? How about reduced GI motility? How about miosis?

Answer 372

Mu –> respiratory and cardiac depression, reduced GI motility

Kappa –> miosis

Question 373

What is the name of the drug that inhibits cholesterol absorption from the GI tract?

Answer 373

Ezetimibe

Question 374

How do fibrates work?

Answer 374

They activate the peroxisomal proliferator-activated receptor alpha, which is a transcription factor that increases lipoprotein lipase activity.

Question 375

In a positively skewed distribution, the mean is generally ______ than the median?

Answer 375

mean is generally higher than the median.

Question 376

What is the most common genetic cause of idiopathic pulmonary hypertension? What is medical treatment while awaiting transplant?

Answer 376

Mutation to BMPR2 gene (which is pro-apoptotic).

Medical tx while awaiting transplant is bosentan. It is an endothelin antagonists. Endothelin is a potent vasoconstrictor.

Question 377

In order to undergo reassortment, what sort of viral genome must you have?

Answer 377

A segmented genome.

Question 378

What are the major side effects associated with CCBs like amlodipine?

Answer 378

Headache, dizziness, flushing and peripheral edema.

Question 379

Wide, fixed splitting of S2 that does NOT vary with respiration is associated with what?

Answer 379

Atrial septal defect.

Question 380

How does hypercalcemia present?

Answer 380

weakness, constipation, confusion (these three due to impaired depolarization of neuromuscular membranes), and polyuria/polydipsia (due to impaired concentration of urine in the distal tubule).

Question 381

Why can patients w/ granulomatous disease and sarcoidosis have hypercalcemia?

Answer 381

Because activated macrophages in these diseases express 1-a-hydroxylase, this leads to excess 1,25-dihydroxyvitamin D, which can lead to hypercalcemia.

Question 382

What is seen histopathologically in HIV associated dementia?

Answer 382

Microglial nodules. These form from activated macrophages and microglial cells.

Question 383

What does IgM in an infant’s serum suggest?

Answer 383

Some sort of intrauterine infection like congenital CMV.

Question 384

What is a craniopharyngioma derived from?

Answer 384

It is a remnant of Rathke’s pouch, which is a diverticulum of the roof of the embryonic oral cavity (oral ectoderm).

Question 385

What does the diencephalon become?

Answer 385

The thalamus, hypothalamus and third ventricle.

Question 386

What is the precursor lesion to squamous cell skin cancer? How is it described?

Answer 386

Actinic keratosis = precursor lesion. It is described as a scaly plaque.

Question 387

What is the male embryological equivalent (i.e. develops from the same place) of the labia majora?

Answer 387

The scrotum. These things develop from the labialscrotal swelling.

Question 388

What does the urogenital folds become in men and women respectively?

Answer 388

The ventral shaft of the penis (penile urethra) and the labia minoria respectively.

Question 389

What does the genital tubercle become in men and women respectively?

Answer 389

Men: glans penis and corpus cavernosum and spongiosum.

Women: glans clitoris and vestibular bulbs.

Question 390

How is diagnosis of ankylosing spondylitis made?

Answer 390

Through imaging like X-ray of the sacroiliac joints. These pts have “bamboo spine.” There are no serum markers for AS that allow dx.

Question 391

Anti-nuclear antibody testing is done for what disease?

Answer 391

SLE

Question 392

Which classes of heart-block are generally treated with a pacemaker.

Answer 392

Type 3 and mobitz type 2 (where there are dropped beats that are not preceded by a lengthening of the PR interval).

Question 393

Cardiomegaly (e.g. from dilated cardiomyopathy) that leads to dysphagia and indentation and posterior displacement of the esophagus is due to enlargement of what part of the heart?

Answer 393

The left atrium.

Question 394

What is the most common porphyria and how does it present?

Answer 394

Porphyria cutanea tarda. Presents w/ blistering photosensitivity (i.e. man who gets vesicles and blisters on the skin after sun exposure that takes weeks to heal).

Question 395

What enzyme is deficient in porphyria cutanea tarda and what substrate accumulates?

Answer 395

Enzyme = uroporphyrinogen decarboxylase.

Substrate that accumulates = uroporphyrin (causing tea-colored urine).

Question 396

How does riboflavin (B2) deficiency present?

Answer 396

Cheilosis (inflammation of lips, scaling and fissures out mouth corner), and corneal vascularization.

Question 397

In internuclear ophthalmoplegia, the MLF lesion is ipsalateral or contralateral of the affected eye?

Answer 397

Ipsalateral. (I am pretty sure, check p.490 of first aid to double check).

Question 398

What amount of functional LDL receptors are present in familial hypercholesterolemia where pts have tendon xanthomas?

Answer 398

None (per firstaid p.71). They are completely absent or defective.

Question 399

What is the personality disorder where the person is voluntarily withdrawn, has limited emotional expression and is content with social isolation?

Answer 399

Schizoid personality disorder

Question 400

What is the personality disorder where the person has an eccentric appearance, has odd beliefs or magical thinking, and interpersonal awkwardness?

Answer 400

Schizotypal personality disorder

Question 401

How do you distinguish between primary hyperaldosteronism (i.e. adrenal adenoma or Conn syndrome) and secondary hyperaldosteronism (i.e. renovascular HTN or JG tumor)?

Answer 401

In primary renin is decreased whereas in secondary renin is increased.

Question 402

In the sensory and motor homonculi, what does the lateral part correspond to? How about the part closest to midline?

Answer 402

Most lateral is stuff with the face like the eyes and the tongue. Most midline are the legs and feet, with the arms being lateral to it.

Question 403

What skin lesion is described as firm, smooth umbilicated papules? What causes it?

Answer 403

Molloscum contagiosum. Caused by poxvirus.

Question 404

The scaffold of lung parenchyma around the airways creates a force to hold them open. This force is knows as? In what sort of lung disease is this increased?

Answer 404

Radial traction. In restrictive lung disease radial traction is increased as the increased fibrosis basically creates more tension between the parenchyma and the airway lumen.

Question 405

What is sulfasalazine and what is it used to treat?

Answer 405

It is a combo of the abx sulfapyridine and the anti-inflammatory 5-aminosalicylic acid. It is used to treat Crohns and UC.

Question 406

How does Churg-Strauss present?

Answer 406

It is also known as as eosinophilic granulomatosis with polyangiitis. It presents w/ asthma, sinusitis, skin nodules or purpura, peripheral neuropathy and can also involve heart, GI and kidneys.

Question 407

What is the triad seen in granulomatosis w/ polyangiitis (Wegener’s)?

Answer 407

Focal necrotizing vasculitis, necrotizing granulomas in the lung and upper airway, necrotizing glomerulonephritis.

Question 408

Describe the upper respiratory sxs that can be seen with granulomatosis w/ polyangiitis?

Answer 408

perforation of nasal septum, chronic sinusitus, otitis media, mastoiditis.

Question 409

In what population is sarcoidosis most common?

Answer 409

Africa-American females.

Question 410

What are some things that are associated w/ sarcoidosis?

Answer 410

Restrictive lung disease (interstitial fibrosis), erythema nodosum, lupus pernio, Bells palsy, uveitis, hypercalcemia.

Question 411

On a cross section of the cavernous sinus, what is the CN that is running in the interior closest to the internal carotid?

Answer 411

CN6 (abducens)

Question 412

On a cross section of the cavernous sinus, list the CNs top to bottom of those that are right on the edge. This does NOT include the one more medial that runs in close association with internal carotid.

Answer 412

Top to bottom: CN3, CN4, CN5 ophthalmic division, CN5 maxillary division.

Question 413

How does chronic abuse of inhaled glue present?

Answer 413

Headache that is bilateral and at the temples, confusion (forgetting names, dates, places, etc.), falls, broad-based ataxic gait. (this is per a question on form 17).

Question 414

What characteristic of amyloid gives its characteristic staining appearance?

Answer 414

Its Beta-pleated sheet structure.

Question 415

How does cyclosporin work?

Answer 415

It blocks T cell activation by preventing IL-2 transcription.

Question 416

What makes up the striatum in the brain? How about the lentiform nucleus?

Answer 416

Striatum = caudate + putamen

Lentiform nucleus = putamen + globus pallidus.

Question 417

Why can Turner syndrome pts present w/ amenorrhea in adolescence?

Answer 417

Low estrogen levels due to non-functional ovaries (histo reveals streaks of tissue devoid of primordial follicles).

Question 418

What congenital cardiac defect is associated w/ “an egg on a string” appearance on CXR?

Answer 418

Transposition of the great vessels

Question 419

What is the most common cause of death in infants w/ congenital diaphragmatic hernia?

Answer 419

Pulmonary hypoplasia.

Question 420

Embryologically, what muscle is the source of the cremaster muscle?

Answer 420

The internal oblique muscle

Question 421

What nerve innervates the cremaster muscle?

Answer 421

Genitofemoral nerve

Question 422

Deep to Superficial, what are the layers of the spermatic cord and what are they derived from embryologically?

Answer 422

internal spermatic fascia derived from transversalis fascia, then cremasteric muscle and fascia derived from internal oblique, and lastly is the external spermatic fascia derived from external oblique.

Question 423

What layer of the skin are melanocytes located?

Answer 423

Stratum basalis.

Question 424

What are the layers of skin from superficial to deep?

Answer 424

Corneum, lucidum, granulosum, spinosum and basale.

Question 425

Which nerve and from what spinal levels stimulate sperm to move into the urethra (aka emission)(?

Answer 425

Sympathetic fibers in the hypogastric nerves from T11-L2

“Point , squeeze and shoot” is a helpful way to remember the types of fibers for erection, emission and ejaculation respectively.

Question 426

Which nerve is responsible for ejaculation?

Answer 426

The pudendal nerve - somatic and visceral fibers

Question 427

What does musculocutaneous nerve injury present as?

Answer 427

Inability to flex and supinate the forearm. Also, loss of sensation over the lateral forearm.

Question 428

What does the Edinger-Westphal nucleus contain and what do these fibers do?

Answer 428

Contains preganglionic parasympathetic neurons that travel w/ CNIII and help w/ pupillary constriction and accommodation.

Question 429

The _________ nerve arises from L1, passes through the inguinal ligament on top of the spermatic cord, and supplies cutaneous sensation to the scrotum/labia and medial aspect of the thigh.

Answer 429

ilioinguinal nerve

Question 430

Forceful, postprandial, nonbilious vomiting in the first 2 months of life suggests …?

Answer 430

Pyloric stenosis

Question 431

Oocytes are arrested in ______ until ovulation and at ovulation they progress w/ meiosis until arresting in _____ until fertilization?

Answer 431

Prophase I, metaphase II

Question 432

In regards to enzyme kinetics, a dissociation constant is equal to what?

Answer 432

The concentration of substrate at which the binding site on the enzyme or protein is 50% bound by substrate.

Question 433

What causes acute serum sickness and how does it present?

Answer 433

Caused by a type III hypersensitivity rxn in response to antigen like chimeric antibody therapy (e.g. infliximab). This resents in tissue deposition of circulating immune complexes and produces fever, pruritic rash, arthralgias and low C3 and C4 in the serum.

Question 434

Connexins help make up what structure?

Answer 434

Gap junctions

Question 435

Claudins and accludins help make up what structure?

Answer 435

Tight junctions

Question 436

What happens to stop the apnea in OSA?

Answer 436

PO2 declines and PCO2 rises until chemoreceptors in the carotids and brainstem trigger arousal and return of pharyngeal muscle tone allowing a patent airway again.

Question 437

How do you calculate standard error?

Answer 437

SE = SD/ square root of n

Question 438

How do you calculate the confindence interval of the mean?

Answer 438

CI = mean +/- ((Z-score for chosen confidence interval)x(SE))

*Note that the Z-score reflects how many SDs away from the mean, the percentage you’ve chosen falls. I.e. 95% of values in a normal distribution are 1.96 SD from the mean.

Question 439

Through what area does herniation occur in indirect inguinal hernia and what embryologically predisposes to this?

Answer 439

It goes through the internal (deep) inguinal ring, following the path of the spermatic cord. Failure of closure of the processus vaginalis predisposes to this.

Question 440

What structures are derived from the mesonephric duct?

Answer 440

The vas deferens, along with the epididymis, seminal vesicles, and ejaculatory duct, is derived from the mesonephric duct.

Question 441

Valgus stress test of the knee tests what ligament?

Answer 441

MCL

Question 442

In a “straddle injury” where there is perineal damage and urine leaks into the scrotom and the perianal region, what part of the urethra is damaged?

Answer 442

Rupture of the urethra below the urogenital diaphragm (at the junction between the membranous and the penile urethra). This is rupture of the anterior urethra.

Question 443

Is it endometrial hyperplasia or adenomyosis that presents with a globally enlarged uterus?

Answer 443

Adenomyosis. Conversely, endometrial hyperplasia generally presents w/ post-menopausal bleeding and is known for increased risk of endometrial carcinoma.

Question 444

What interaction causes Hgb sickling in sickle cell disease?

Answer 444

The mutations creates a hydrophobic pocket on the B globin surface that allows for hydrophobic interactions between globin molecules. This interaction leads to sickling.

Question 445

What promotes red cell sickling in sickle cell anemia?

Answer 445

Low oxygen, increased acidity and dehydration.

Question 446

What are the three phases (in order) that occur in Paget’s disease of the bone?

Answer 446

1 = osteolytic phase where osteoclasts predominate and increased resorption is prominent.

2= mixed phase which is characterized by a rapid increase in osteoblastic bone formation with persistent osteoclastic activity.

3 = osteosclerotic phase during which osteoblast activity is dominant. Remodeling results in a dense, hypovascular mosaic pattern of lamellar bone w/ irregularly and haphazardly oriented sections separated by cement lines.

Question 447

What neural structure lies within the fascia surrounding the prostate? What does this structure do?

Answer 447

Prostatic plexus. It originates from the inferior hypogastric plexus and carriers post-ganglionic parasympathetic fibers. It gives rise to the cavernous nerves that are responsible for erection.

Question 448

Branches of the pudendal nerve innervate which sphincters?

Answer 448

The external urethral sphincter and the anal sphincters.

Question 449

______ are the form of dendritic cell most commonly found in the skin and mucous membranes and contain characteristic racquet-shaped granules known as birbeck granules.

Answer 449

Langerhans cells.

Question 450

Describe the process of base excision repair included the order of the enzymes used

Answer 450

glycosylase cleaves the messed up base and leaves a site w/o a nitrogenous base. endonuclease cleaves the 5’ end and lyase cleaves the 3’ sugar-phosphate. Lastly, DNA polymerase fills in the single nucleotide gap and ligase seals the nick.