practice test 1 Flashcards
A patient that was in a vehicle collision with no other medical conditions and is in a coma, blood pressure 84/50 pulse 122 then resuscitated and put on a ventilator 2 days later develops a bilateral pulmonary edema in the absence of heart failure, what caused the pleural effusion
acute respiratory distress syndrome
injury to alveolar pneumocytes and pulmonary endothelium from trauma induced pulmonary contusions or fat emboli
assign the following speeds of conduction to the either the SA node, AV node, purkinje, ventricular myocardium 1.1 m/sec .05 2.2 .3
1.1: SA node
.05: AV node (slowest)
2.2: purkinje (fastest)
.3: ventricular myocardium
what causes destruction of normal trabecular bone pattern, mixed rasiodense (sclerotic) and radiolucent (lytic) areas, and periosteal new bone formation with lifting of the periosteum
osteosarcoma
____ is the feeling of a lump in the throat without accompanying physical, endoscopic, or radiologic findings of esophageal obstruction
globus sensation
describe the crystals in gout
negatively birefringent: yellow when parallel and blue with perpendicular
What teratogenic effect do ACE inhibitors and ARBs have
impair fetal renal development (renal hypoplasia or dysgenesis) and inhibit fetal urine production (oligohydramnios)
What is the treatment for influenza and its mechanism of action
oseltamivir (tamiflu)
inhibits neuroaminidase which is normally responsible for cleaving the terminal sialic acid residues on hemagglutinin binding of glycoconjugate receptors
so newly synthesized virions remain adherent to host cell surface and unable to infect new cells
what is the appearance of DNA fragments in multiples of 180 base pairs on gel electrophoresis indicative of
“DNA laddering”: indicator of apoptosis
diazepam MOA
benzodiazepine
define germline mosaicism
presence of genetically different cell lines within the oocytes or spermatocytes
germline mosaicism typically results from a mutation during the first stages of embryonic development
IL-2 is exclusively produced by what cells
T lymphocytes
_____ are adhesion molecules that bind epithelial cells together within tissues and bind to cadherin molecules on adjacent cells to form adherens junctions and _____. In contrast, cell adhesion to the basement membrane is mediated primarily by ____ and these structures rely on _____
cell to cell: cadherins, desmosomes
cell to basement membrane: hemidesmisomes, integrins
Molluscum contagiosum is caused by what virus? describe how this virus appears histologically
poxvirus
epidermal hyperplasia long with molluscum bodies: large eosinophilic cytoplasmic inclusions made of virus particles (cytoplasmic inclusion bodies)
The ____ runs just posterior to the knee joint and is fixed proximally and distally by the adductor magnus and soleus muscles, respectively, making it highly susceptible to injury during tibiofemoral dislocation
popliteal artery
define sublimation
channeling impulses into socially acceptable behaviors
define projection
attributing one’s own feelings to others
What is the GFR (%) compared to normal immediately following a heminephrectomy? six weeks following?
50%
80%
Phosphodiesterase-5 inhibitors (sildenafil) increase intracellular concentrations of _____ in the vascular smooth muscle of the corpora cavernosa which leads to smooth muscle relaxation and subsequent engorgement
cGMP
Damage to the long thoracic nerve along the lateral chest wall may cause paralysis to what muscle
serratus anterior
Describe the relative concentrations of sodium, potassium, bicarb, and chloride excreted by the exocrine pancreas
sodium and potassium are fixed and virtually identical to plasma levels
secretin –> increases pancreatic flow rate –> high bicarb and low chloride
what is the difference between schizophreniform disorder and schizophrenia
schizophreniform disorder: longer than a month and shorter than 6 months
schizophrenia: longer than 6 months
how can you calculate the false positive rate?
either (1 - specificity) or
number of false positive tests/healthy controls
How can you calculate the following: absolute risk reduction relative risk reduction relative risk number needed to treat
ARR = control rate of event - treatment rate of event RRR= ARR/control rate of event RR = treatment rate of event/control rate of event NNT= 1/ARR
Fever and mental status/behavior changes with temporal lobe hemorrhage/edema on MRI indicates what diagnosis
encephalitis: HSV1 is the most common cause of sporadic encephalitis
Acute intermittent porphyria is caused by deficiency of ___ and is characterized by intermittent episodes of abdominal pain with neurological manifestations following exposure to an offending medication
porphobilinogen deaminase
Acute intermittent porphyria results from a autosomal dominant defect in porhophilinogen deaminase that can lead to elevated levels of ____ and _____
porphobilinogen aminolevulinic acid (ALA)
In an alcoholic presenting with neurologic symptoms, how can a cobalamin and thiamine deficiency be distinguished
cobalamin deficiency (B12): degeneration of lateral corticospinal tracts (babinski) thiamine deficiency: does not commonly affect lateral corticospinal tracts (no babinski sign)
Surgical removal of what organ leads to improvement in many patients with myasthenia gravis
thymus
A patient presenting with dysmorphic face, cleft palate, and recurrent infections likely has what diagnosis
DiGeorge syndrome (defective development of the pharyngeal pouches –> absent or hypoplastic thymus, craniofacial deformities, conotruncal cardiac defects)
How are the following serum levels effected in DKA: ketone serum pH glucose potassium sodium
hyperketonemia
metabolic acidosis
hyperglycemia (decreased glucose utilization)
hyperkalemia (acidemia drives K+ out of cells through K/H exchangers and lack of insulin to drive K into cells)
hyponatremia (due to osmotic activity of serum glucose –> osmotic diuresis)
What causes a female external genitalia and breasts with a vagina ending in a blind pouch, elevated serum testosterone and LH and normal FSH
complete androgen insensitivity
Before surgical removal of a pheochromocytoma, what medication should be administered
phenoxybenzamine
and a beta blocker
(beta blocker should never be administered first bc of unopposed alpha stimulation)
Premature infants are at high risk of intraventricular hemorrhage due to what?
germinal matrix fragility
Misoprostol MOA
prostaglandin E1 analog (receptor agonist)
can be used to prevent or treat NSAID induced gastritis and peptic ulcer formation and fetal loss
Patients with nonsteroidal anti-inflammatory drug exacerbated respiratory disease often have nasal polyps and chronic rhinosinusitis and develop worsening nasal congestion and/or bronchospasm after ingesting aspirin or NSAIDS due to build up of what
leukotrienes
Intercellular bridging and keratin pearls (foci of central keratinization within concentric layers of squamous cells) are characteristic of what tumor
squamous cell carcinoma
what secondary effect does nitroglycerin have on heart rate
reflex tachycardia
How does the function of CTFR differ in the lungs vs sweat glands
sweat glands: resorb chloride and enhances sodium resorption
respiratory (and intestine): secretes chloride in lumen and has an inhibitory effect on ENaC, decreasing luminal sodium absorption
(sweat–> resorb electrolytes; intestine and resp –> secrete electrolyte in lumen)
describe allelic heterogeneity
different mutations in the same genetic locus cause similar phenotypes
(ex. patients with beta thalassemia can have 3 different mutations that all cause the disease. but, like duchenne vs becker, the exact phenotype can vary based on individual mutations)
In asthma, mast cells and eosinophils release _____ that trigger bronchospasm, bronchial mucus secretin, and bronchial edema
cysteinyl-containing leukotrienes (C4, D4, E4)
list clinical manifestations of hereditary hemochromatosis
hyperpigmentation (bronze diabetes)
arthralgia
hepatomegaly, cirrhosis, hepatocellular carcinoma
diabetes mellitus, secondary hypogonadism and hypothyroidism
restrictive or dilated cardiomyopathy and conduction abnormalities
increased susceptibility to listeria, vibrio vulnificus, and yersinia enterocolitica
what is the pathogenesis of hemochromatosis
excessive gastrointestinal absorption of iron
How does Cirrhosis cause splenomegaly
increased pressure in the portal venous system causes splenic vein hypertension and splenomegaly
FGFR3 gene mutation results in what
achondroplasia
gain of function of fibroblast growth factor receptor 3 –> inhibits excessive cartilage proliferation
A patient with low immunoglobulins, low CD19 cells and normal T cells that has recurrent infections likely has what disease and what is the gene mutation
X-linked agammaglobulinemia
BTK gene mutation –> defective Bruton tyrosine kinase –> impaired B cell maturation and immunoglobulin production
Proteins destined for the endoplasmic reticulum posses _____ signal sequences that identify them as such. These sequences are translated in the ____ and are rapidly recognized by ____ which halt translation and target the ribosome to protein pores in the rough endoplasmic reticulum.
N-terminal peptide
cytosol
SRPs (signal recognition particles)
(without the N-terminal hydrophobic amino acid sequence, these would accumulate in the cytosol)
High amounts of branched chain alpha keto acids in the blood and urine in a baby with poor feeding and occasional vomiting likely has what disease
maple syrup urine disease
defect in the branched-chain alpha keto acid dehydrogenase complex
what cofactors/coenzymes are required by branched chain alpha keto acid dehydrogenase
thiamine (B1) FAD NAD+ CoA lipoic acid
What is the diagnosis of a a fetus who demonstrates ascites, bilateral pleural effusions, and pericardial effusion who is the child of 2 asian decent parents who both have histories of blood disorders
hydrops fetalis secondary to alpha thalassemia
what is seen on blood smear of alpha thalssemia minor
mild microcytic anemia
In a patient with normal serum concentrations of testosterone and LH, but low testosterone concentrations in the seminiferous tubules and epididymis, what cells are likely dysfunctioning
sertoli cells
produce androgen binding protein which binds testosterone and DHT to reduce their diffusion out of the luminal fluid
what hormone promotes glycogenolysis and gluconeogenesis in the liver
glucagon (and epinephrine)
what receptor does glucagon bind
Gs –> adenylate cyclase –> cAMP
Where do the following supply sympathetic innervation: stellate ganglion superior cervical ganglion thoracic splanchnic nerves thoracic sympathetic trunk vagus nerve
stellate (cervicothoracic): upper extremity
superior cervical: head and neck
thoracic splanchnic: abdomen
thoracic: axilla, ect.
vagus: viscera of thorax, foregut, midgut
osteoarthritis is characterized by the degredation of ____- and _____ within articular cartilage
type II collagen
proteoglycans
In females, the gubernaculum becomes the _____ which passes through the inguinal canal and out to attach to the labia majora and the superior portion persists as the ______ which connects the uterus to the ovary
round ligament
uteroovarian
Paragangliomas, arising from chromaffin cells at the organ of Zuckerkandl are similar to what tumors that arise in the adrenal medulla
pheochromocytoma
How are the following effected in a PE:
pH
PaCO2
PaO2
pH: decreased
PaCO2: increased
PaO2: decreased
Pulmonary arterial hypertension is a result from what?
pulmonary arterial endothelial dysfunction
(hypertrophy of smooth muscle medial layer and hyperplasia of the intimal layer followed by progressive intimal fibrosis with eventual development of plexiform lesions)
what genetic disorder results in early onset osteoporosis/increased bone fragility which may also cause visibility of the choroid layers underlying the sclera of eye
osteogenesis imperfecta (mutation in COL1A1 and COL1A2 genes which encode proteins that form type I collagen)
Hypoglycemia after prolonged fasting with inappropriately low ketone bodies suggest impairment of what metabolic process
beta oxidation
or ketone production
Ras is an oncoprotein that is a component of what intracellular function
MAP-kinase signal transduction
transmits stimulus from the receptor on the cell surface to the nucleus promoting mitogenesis
What is the function of MYC
nuclear phosphoprotein that functions as a transcription activator controlling cell proliferation, differentiation, and apoptosis
what is the function of BRCA1
encodes DNA repair enzyme
what is the function of cyclin D1
promoter of G1 to S during the cell cycle
what is the function of Rb
nuclear phosphoprotein that regulates the G1 to S checkpoint
What tumor is composed of polygonal, eosinophilic cells that stain positive for neuropeptides such as chromogranin and syntaptophysin and what do they typically release
carcinoid tumor
serotonin
What is required in order for an organism to be susceptible to any penicillins
cell wall with peptidoglycan
Eukaryotic translation is initiated why the small ribosomal subunit binds the 5’cap of mRNA and scans for the start codon(___) within the Kozak consensus sequence. Ribosomal binding of the 5’ cap is facilitated by a family of proteins known as the ______
AUG
eukaryotic initiation factors
During apoptosis, the activation of caspases results in degradation of ____, leading to interruption of translation. As a result, many proteins necessary for apoptosis are translated using what alternative method?
eIF (eukaryotic initiation factors)
internal ribosome entry: internal ribosome entry site (IRES) attracts ribosome to mRNA and allows translation to begin in the middle of the mRNA sequence
fissures, abcesses, fistulae, mouth ulcers accompanied by abdominal pain, diarrhea, and low grade fever are seen in what disease? where does it most frequently involve, which is a good site for biopsy
Crohn disease
ileum
What location is most commonly affected by ulcerative colitis?
colon
what are the most commonly effected locations by celiac
distal duodenum and proximal jejunum
In treating hepatic encephalopathy, should the urine or colon be acidified or alkalinized
colon
acidified
(lactulose is degraded by colonic bacteria to form lactic acid and acetic acid which convert NH3 to NH4)
CYP450 inducers have what effect on INR of patients taking warfarin
decrease
increased metabolism of warfarin –> decreased warfarin effect –> more clotting
name 4 CYP450 inducers
carbamazepine
phenytoin
phenobarbital
rifampin
inorder to induce bronchodilation, what should be increased intracellularly
cAMP (beta 2 –> Gs –> cAMP)
Bone pain and weakness in the setting of limited nutritional intake and minimal sunlight exposure is highly suggestive of what diagnosis
osteomalacia (decreased mineralization of osteoid)
In a patient with longstanding diabetes, exertional leg pain that has begun to hurt at night unless he sleeps sitting up, thin skin, and a small ulcer at the tip of toe likely has what underlying pathology
peripheral arterial disease
arterial atherosclerosis
What is LiFraumeni syndrome and what is the genetic cause
autosomal dominant inactivating mutation of TP53 (needs 2 hit for malignant transformtation)
causes early onset malignancies including breast cancer, bone and soft tissue sarcomas, adrenocortical carcinoma, and brain tumors
Aneurysmal dilation of the aortic arch can compress the _____, resulting in hoarseness due to paralysis of what muscles
left recurrent laryngeal nerve
intrinsic muscles of the larynx responsible for sound production (posterior and lateral cricoartenoids, oblique and transverse arytenoids, thyroarytenoid) except the cricothyroid
In general, DNA viruses (except for ____ ) replicate in the _____. RNA viruses (except for _____ and _____) replicate in the _____
pox virus nucleus orthomyxoviruses retroviruses cytoplasm
____ is most commonly asymptomatic or a mild pneumonia with pleural effusion. A rash and symmetric arthralgias can develop. Rarely, it can cause formation of a thin-walled cavity in the lung which may produce hemoptysis in addition to fever and cough.
coccidioides immitis (coccidioidomycosis)
What are characteristic findings of Hashimoto thyroiditis on biopsy
lymphocytic infiltration
follicular destruction
germinal center formation
Hurthle cells (enlarged epithelial cells with eosinophilic cytoplasm and prominent nucleoli)
ASD is associated with what heart sound
fixed widened S2 split
What is the immature defense mechanism of focusing on nonemotional aspects to avoid distressing feelings
intellectualization
What is the pathogenesis of Achalasia
an inflammatory infiltrate composed of mainly lymphocytes and eosinophils develops around the nitric oxide-producing neurons in the myenteric plexus, these neurons, responsible for esophageal smooth muscle relaxation, are preferentially destroyed
Acute onset anemia in a male of African, Asian, or Mediterranean descent who is being treated with a sulfonamide is most likely due to what
G6PD deficiency
compare Brocas aphasia to Wernickes aphasia
Brocas= expressive/motor aphasia Wernicke= speech comprehension
Efferent neuron axons tend to be myelinated, with what notable exception?
postganglionic autonomic neurons
How does sample size effect the standard of error
standard of error decreases and sample size increases
What is the most common cause of viral meningitis and is positive sense single stranded RNA
enteroviruses which are in the picornavirdae family
What brings together the alpha and beta chains of the MHC class II molecule and is then degraded before an extracellular peptide is inserted between the alpha and beta chains
invariant chain
what cause of microcytic, hypochromatic anemia may present with burning sensation in mouth, reduced taste, and lip dryness
iron deficiency
compare the clinical features of prader willi syndrome and angelman syndrome
prader-willi: hypotonia, hyperphagia/obesity, short stature, small hands/feet, hypogonadism, dysmorphic face, intellectual disability
angelman: epilepsy, seizure, ataxic gait/tremor, poor motor and language development, inapporpriate laughter/smiling, intellectual disability
compare the genetic cause of prader-wili vs angelman syndrome
prader-wili: loss of paternally inherited allele from chromosome 15 (15q11-13) (paternal microdeletion or maternal uniparental disomy)
angelman: the opposite (maternal microdeletion or paternal uniparental disomy)
What cause of chronic diarrhea is associated with a skin rash
celiac
cross reactivity between anti-gliadin IgA antibodies and translutaminase at the dermal basement membrane
Lesch-Nyhan syndrome is an X linked disorder caused by deficiency of ______ that results in hyperuricemia
hypoxanthine-guanine phosphoribosyltransferase
Describe the pathogenesis of pernicious anemia including its effect on gastrin
atrophic gastritis (likely autoimmune related) causes hypochlorydria --> increased serum gastrin release (normally inhibitted b yhydrochloric acid) damage to parietal cells --> decreased intrinsic factor release ---> depleted B12 stores --> macrocytic anemia and degeneration of ascending and descending spinal tracts
What cause of a not transilluminating testicular mass diminshes in size when laying down
varicocele
hydrocele may also change in size based on position but would transilluminate
what are possible causes of acanthosis nigricans
insulin resistance
obesity
malignancy (if it appears suddenly, spreads quickly, or involves mucous membranes, or palms and soles)
During normal embryonic development, ____ migrate from the neural crest to the epidermis and _____ migrate from the yolk sac to the gonadal ridge
melanocytes
germ cells
What type of heart malformations are most common in DiGeorge syndrome
conotruncal (outflow tract) defects:
persistent truncus arteriosus
tetralogy of fallot
interrupted aortic arch
In order for class switching to occur, B cells must undergo costimulation by ___ ligand which is expressed on the surface of activated T cells
CD40
hepatosplenomegaly, bone pain with marked osteopenia with cortical collapse, and an enzyme deficiency in an 18 yr old is due to what enzyme deficiency? what is the diagnosis?
Beta-glucocerebrosidase
Gaucher
Angiokeratomas, peripheral neuropathy, and glomerulopathy with an enzyme deficiency is due to what enzyme deficiency and what is the daignosis
alpha galactosidase A
Fabry disease
inflizimab MOA
monoclonal antibody to TNF alpha
etanercept MOA
recombinant TNF receptor fusion protein which inhibits TNF alpha effects
By inhibiting COX-1 in platelets, aspirin prevents the synthesis of _____, a potent stimulator of platelet aggregation and vasoconstriction
thromboxane A2
what organism has reproductive forms that classically exhibit a “broom like” structure on silver staining
aspergillus
Describe transformation mechanism of genetic transfer between bacteria
bacteria uptake naked DNA from the environment and incorporate it into their own genome
describe the conjugation mechanism for genetic transfer between bacteria
DNA is passed from one bacterium to another by direct cell-cell interaction
describe the transduction mechanism of genetic transfer between bacteria
bacteriophage mediated transfer of genetic information
what cause of nephropathy fits the following description as seen in an HIV patient: proteinuria, glomerular epithelial cell enlargement and vacuolization, varying degrees of glomerular capillary wall collapse with many renal tubules showing cystic dilation and are filled with proteinaceous material
focal segmental glomerulosclerosis
What is initial treatment for pneumothorax
needle aspiration or chest tube
patients with suspected tension pneumo should undergo immediate decompression
HOXA13 mutation is a rare, dominantly inherited condition characterized by what malformations
distal limbs (hypoplastic first digits) mullerian fusion abnormalities (uterus didelphys, which can cause miscarriages)
Correction of celiac disease by placing a patient on a gluten free diet will likely lead to what changes in the following: bone resoprtion intestinal Ca absorption renal phosphate reabsorption PTH secretion
bone resorption: decrease intestinal Ca absorption: increase renal phosphate reabsorption: increased PTH secretion: decreased (all do to increased vit D absorption)
The maxillary sinuses are the most commonly affect by rhinosinusitis a their path of drainage , the semilunar hiatus in the _____ nasal meatus, is located superior to the floor of the sinus, impairing drainage while upright
middle
Infarction of territories supplied by the middle cerebral, posterior cerebral, or anterior choroidal arteries may result in what type of vision loss
homonymous hemianopsia
Within the sarcomere: the ___ lengthens during muscle relaxation and shortens during contraction
I band and H band
( I band = sections of thin (actin) filaments that do not overlap the thick (myosin) filaments and H band is the opposite)
(more overlapping occurs in contraction)
