Q Banks: Week of 02/27/17 Flashcards
(219 cards)
1
Q
A patient has a communication between the atria. How can you tell if it is aplasia of the septum secundum or failure of fusion between the septum secundum and septum primum?
A
ASD results from aplasia of the septum secundum, while PFO results from failed fusion. ASD can lead to Eisenmenger’s, while PFO just raises risk of emboli.
2
Q
How can you detect PFO in a bubble study?
A
Have the patient release a Valsalva maneuver which will increase RA pressure and lead to right-left flow.
3
Q
What’s the difference between suppression and repression?
A
Suppression is voluntary and conscious while repression is not.
4
Q
Explain how telomerases work.
A
They add TTAGGG repeats to the 3’ end of chromosomes, primarily in stem cells.
(Think, they TAG repeats of 3 –that is, TTA and GGG – to chromosomes.)
5
Q
Explain how ventilators can be used to lessen cerebral edema.
A
The brain is able to autoregulate blood flow in the range of 50 mm Hg to 140 mm Hg, so when pressures exceed 140 mm Hg the risk of cerebral edema increases. pCO2 is a potent vasodilator because it indicates heavy usage. As such, increasing ventilator settings to make the patient have slight metabolic alkalosis can decrease cerebral vasodilation and thus decrease the risk of cerebral edema.
6
Q
The most common leukemia in children presents with what cell surface receptors?
A
CD19 and CD10
7
Q
___________ can persist for years after a CNS injury.
A
Myelin debris
The blood-brain barrier and astrocytes prevent microglia from clearing away myelin. The bodies of oligodendrocytes go away soon through apoptosis.
8
Q
The rate-limiting step in the synthesis of epinephrine is _____________, while the regulated step is ____________.
A
tyrosine hydroxylase; PNMT
PNMT is upregulated by cortisol from the zona fasciculata. If you resect the pituitary or damage the adrenal cortex, then PNMT levels will fall.
9
Q
How can you differentiate arginase deficiency from the other urea cycle defects?
A
Arginase breaks down arginine to urea and ornithine. (It is the last enzyme in the urea cycle before ornithine re-enters the mitochondria.) Defects in arginase lead to high arginine levels and spastic diplegia.
Uniquely for the urea cycle defects, it does not present with hyperammonemia. The other urea cycle defects, like ornithine transcarbamylase deficiency, present with hyperammonemia and elevated orotic acid.
10
Q
What does ornithine transcarbamylase do?
A
It takes carbamoyl phosphate (made from ATP, NH3, and HCO3 in the mitochondria) and adds it to ornithine to make citrulline which gets exported to the cytoplasm and ultimately converted to urea and back to ornithine.
11
Q
IRS mediates the ____________ effects of insulin, whereas PI3K mediates the ____________ effects.
A
nuclear transcription and cell growth; anabolic and glucose lowering
12
Q
What is the best approach to a patient demanding medically unnecessary treatment (such as a patient demanding antibiotics for a likely viral illness)?
A
Acknowledge the patient’s concerns, explain that that treatment might be harmful, and offer other treatments (such as relief of symptoms).
13
Q
What does a bright border on the gallbladder in a CT indicate?
A
Porcelain gallbladder: a complication of chronic cholecystitis that presents with calcification
This increases the risk of gallbladder adenocarcinoma.
14
Q
Describe the most classic presentation of inflammatory breast cancer.
A
Inflammatory breast cancer invades lymphatic tissue and so causes lymphadenopathy in the axilla (most often). It causes a rash that is characteristically rough, indurated, and itchy.
15
Q
True or false: a two-year-old who has 40 words but only uses one at a time is within normal limits.
A
False. At two, children should have between 50 and 200 words and should be able to make two-word sentences.
16
Q
The inferior epigastric branches off ____________, while the superficial epigastric branches off ____________.
A
of the external iliac superior to the inguinal ligament; of the femoral artery inferior to the inguinal ligament
17
Q
Other than the inferior epigastric, what artery branches off of the external iliac?
A
Deep circumflex iliac
18
Q
People with trochlear nerve palsy have diplopia when looking _____________.
A
down (because the trochlear nerve innervates the superior oblique)
19
Q
True or false: the spleen is a retroperitoneal organ.
A
False.
Suprarenal glands (adrenal glands) Aorta Duodenum (except 1st part) Pancreas Ureter and bladder Colon (ascending and descending) Kidneys Esophagus Rectum
20
Q
Which of the following indicates irreversible cell injury?
• Polysomal disaggregation
•Mitochondrial swelling
•Clumping of nuclear chromatin
•Mitochondrial vacuolization
•Disaggregation of granular elements in the nucleus
A
Mitochondrial vacuolization
Mitochondria can swell reversibly, but if they are true vacuoles then they cannot make ATP and the cell will die.
The rest of the findings are normal.
21
Q
CD14 is a marker of _______________.
A
macrophages
22
Q
What does stimulation of alpha-1 receptors do to the eye?
A
Mydriasis
23
Q
Looking at a graph of pulse pressure, how can you differentiate norepinephrine from dobutamine?
A
Norepinephrine presents with elevated systolic and diastolic pressures, while dobutamine presents with elevated systolic pressure (B1) and decreased diastolic pressure (B2).
24
Q
Morphine binds to a ____________ receptor.
A
Gi
This leads to increased K efflux and decreased Ca influx.
25
ST elevations in aVL and I indicate blockage of ____________.
the left circumflex artery
26
Capillary wall thickening in the glomerulus is characteristic of which disorder?
Membranous nephropathy
27
Explain the embryology of the pancreas.
The dorsal and ventral pancreatic buds arise from the duodenal portion of the foregut. The ventral portion rotates 270º around (to the right first and then back around to the left side of the body) and fuses with the dorsal bud. The dorsal bud is larger and gives rise to the tail, body, and head of the pancreas. The ventral bud is smaller and gives rise to the uncinate process and main duct.
28
A neonate has an intracranial bleed. You're trying to figure out what might have contributed. How can you decide if vitamin K deficiency or germinal matrix fragility is more likely?
The germinal matrix involutes around 28 weeks gestation and is thus a problem for premature infants. Neonatal vitamin K deficiency presents in those born at home because vitamin K is given to babies born in hospitals; the clotting deficiency can persist for up to one month after birth.
29
What is the membrane potential of chloride?
- 75 mV
30
What is the membrane potential of calcium?
+ 125 mV
31
What does ANP do?
* Induces natriuresis
* Relaxes arteries
* Restricts the secretion of aldosterone
32
True or false: ketone generation is used to maintain blood glucose from 30 hours of fasting on.
False. Ketones are themselves used to generate acetyl-CoA and cannot make glucose.
Glycogenolysis maintains blood glucose for the first 12 hours and then gluconeogenesis maintains it after that.
33
How long must the SIGECAPS criteria be present to qualify as major depression disorder?
Greater than 2 weeks
34
What's the difference between persistent depressive disorder and major depression disorder?
PDD is MDD that has lasted for more than two years.
35
Adjustment disorder with depressed mood is ________________, compared to MDD.
less severe
36
Recurrent ____________ are suggestive of sickle cell anemia.
abdominal and bone pain
37
What are some clinical symptoms of PKD?
* Hypertension
* Hematuria
* Flank pain
38
"Infiltration of the [intestinal] lamina propria with atypical lymphocytes" describes what condition?
MALT lymphoma
39
Keloids result from overexpression of what cytokine?
TGF-beta
40
If you injure the nerve that passes through the popliteal fossa, what motor and sensory deficits are you likely to have?
Lesions of the tibial nerve in the popliteal fossa will lead to loss of the following:
• Motor: plantarflexion and inversion
• Sensory: plantar surface of the foot, lateral surface of the foot, and posterior calf
41
The ____________ dermatome covers the anterior surface of the knee.
L4
42
Which two dermatomes cover the posterior leg?
S1 (lateral) and S2 (medial)
43
The Romberg test stresses the patient's ______________.
proprioception
44
Why does left-heart failure lead to dyspnea?
The increased fluid present in the pulmonary veins leads to increased fluid in the lung interstitium. That amount of extra fluid decreases the lung compliance and can mimic restrictive lung disease.
45
A patient undergoes a cardiac stress test. While resting, his QRS is normal duration. At near-maximal heart rate, however, his QRS is prolonged. What class of drug is he likely taking for his atrial fibrillation?
IC
All of the class I drugs can prolong the QRS complex, particularly in a use-dependent manner.
46
Three genetic mutations can caue pheochromocytoma: _______________.
RET, VHL, and NF-1
47
Three children have the same genetic disorder. One of them, however, has it more severely than the others. What principle can likely explain this?
It could be two things:
- The disorder might have variable expressivity.
- Heteroplasmy: there are many mitochondria in an ovum. Some may be affected while others aren't. All children of an affected mother will be affected, but some may be less affected if they inherited fewer mutated mitochondria.
48
What kind of protein does hydrochlorothiazide inhibit?
NaCl cotransporter that generates a gradient that pulls calcium into the interstitial fluid.
49
Migraines result from ____________ sumatriptan causes _______________.
vasodilation; vasoconstriction (from 5-HT1b agonism)
50
What does agonism of 5-HT1b (by sumatriptan) cause?
Decreased release of vasoactive peptides
51
The dexamethasone suppression test tells you if ______________.
the ACTH-secreting tumor is in the pituitary – in which ACTH will be suppressed – or ectopic – in which ACTH won't be suppressed
52
Yellow-brown pigment in the cardiac myocytes of a 78-year-old likely are ___________.
lipofuscin (peroxidized lipids)
53
Glioblastoma multiforme arise from ____________.
astrocytes
54
In addition to central necrosis and palisading cells around the periphery, glioblastoma multiforme presents with _____________.
vascular proliferation
55
Mutations in ___________ cause early adenomas (in the colon) to mature into late adenomas, while mutations in __________ promote the transition to carcinoma.
KRAS; p53
56
Mutations in APC/beta-catenin promote ____________.
development of early adenomas (while KRAS and p53 are later)
57
Myofibroblasts and matrix metalloproteases might be present in what kind of wound healing stage?
Contracture
Note: MMPs although for tissue remodeling and for making space for myofibroblasts.
58
Psoriasis presents with a thin or absent stratum ________.
granulosum
59
What cells might be present in the tissue of someone with psoriasis?
Neutrophils (attracted from the T cells)
60
What is an important concept to know regarding cilia and glands in the airway?
The airway is set up to prevent the accumulation of mucus in the alveoli. As such, cilia continue past ALL of the epithelial glands so that they can catch any mucus that slides down.
The cilia extend through the terminal bronchioles.
61
What does withdrawal from cocaine and the other amphetamines look like?
* Hypersomnia (because they weren't sleeping)
* Hyperphagia (because stimulants are appetite suppressants)
* Depression (crashing)
* Vivid dreams
Note: withdrawal from cocaine does not produce specific physical signs (as in the cases of alcohol and opiate withdrawal)
62
Describe pyruvate kinase deficiency.
Pyruvate kinase (which converts PEP to pyruvate and generates one ATP) is important in the maintenance of RBCs because they do not have mitochondria. Patients with this will thus have lots of hemolysis and expanded RBCs.
63
Why does the spleen expand in hemolytic disorders?
If the reticuloendothelial cells are forced to work extra (as they would in a patient with pyruvate kinase deficiency), then they undergo hyperplasia. Specifically, the red pulp undergoes hyperplasia.
64
What protein disassembles viral glycoproteins for expression in MHC I receptors?
Ubiquitin and proteasomes
65
Areas of necrosis in the brain will usually be repaired by ______________.
glial hyperplasia
66
Describe what levels of posterior rib fractures can lead to liver, spleen, and kidney lacerations.
* Spleen: left 9, 10, and 11 ("spleEN = tEN")
* Kidneys: left and right 12
* Liver: right 9, 10, and 11
67
Explain the biochemical mechanism of how the intestines inhibit acid secretion.
The arrival of food in the intestines leads to release of peptide YY which binds to the enterochromaffin-like cells. ECLs usually secrete gastrin, but PYY inhibits this.
68
What is lobar sequestration?
A congenital lung malformation in which lung tissue does not communicate with the airway
69
What is a key inhibitory molecule in beta-oxidative metabolism?
Malonyl-CoA
Think about it: malonyl-CoA represents the anabolic production of fatty acids. Thus, having this molecule inhibit carnitine acetyltransferase – which takes fatty acids from the cytoplasm to the mitochondria – serves to prevent the breakdown of newly formed fatty acids in the cytoplasm.
70
How can aortic dissection lead to discrepancies in the BP of the left and right arms?
Aortic dissection leads to bleeding around the artery. The hematoma can put pressure on arteries and even occlude whole branches. Thus, a dissection in the ascending aorta can lead to occlusion of the brachiocephalic trunk and thus low BP in the right arm.
71
Aortic dissections are acutely caused by ___________.
tears in the intima
72
True or false: medical calcific stenosis can lead to aortic dissection.
False. Generally, medial calcific stenosis leads to hypertension due to arterial inflexibility.
73
What is the greatest risk factor for aortic dissection?
Hypertension
74
In a positively skewed plot, the mean is _________ the mode.
greater than
75
In an older patient, _________________ should be included in the hospital admission process.
discussion of advanced directives
76
The extrahepatic symptoms of HBV are said to be ___________.
serum-sickness like (as in arthralgia, fever, lymphadenopathy, and kidney issues)
77
What is the effect of nitroprusside?
It is a balanced venous and arterial vasodilator. As such, it decreases preload and afterload and roughly maintains stroke volume.
78
In which patients is pO2 the dominant driver of respiration?
Those with COPD
People with COPD have chronic hypercapnia and thus become desensitized to pCO2. Also, they're more likely to have extreme hypoxemia and have their respirations driven by pO2.
79
Pulmonary stretch receptors and C fibers sense _______________.
the degree of expansion and thus they control how much the lungs expand in normal breathing
80
The carotid bodies (mediated by which nerve?) sense _______________.
H+, pO2, and PCO2
The nerves are mediated by the glossopharyngeal nerve.
81
Explain the mechanisms of hypercalcemia in multiple myeloma.
* MM directly metastasizes to the bone and causes the release of calcium, thereby raising serum calcium levels.
* Because the PTH system is still intact, PTH is suppressed.
* Amyloid cast nephropathy leads to kidney damage.
* The kidney damage and low PTH leads to low vitamin D.
* PTHrp is not present.
* Low PTH and hypercalcemia lead to increased urinary excretion of calcium.
82
True or false: carvedilol should not be used in systolic heart failure due to vasodilatory effect.
False. It is safe and recommended in SHF.
83
What is a normal post-void residual urine volume?
50 mL or less
84
To what action potential value does QT prolongation correspond?
Lengthening of the phase 2 plateau
As such, drugs that prolong the plateau – such as class IA antiarrhythmics and the class III drugs – can lead to QT prolongation.
85
How might you hear torsades de pointes described?
As "polymorphic QRS complexes of varying amplitude and duration"
86
The hallmark histologic sign of acute viral hepatitis is _________________.
hepatocyte necrosis with ballooning degeneration
87
True or false: chlordiazepoxide should not be used to treat delirium tremens because of its long half-life.
False. It is preferred because of its self-tapering effect. Caution: do not use in patients with liver failure.
88
True or false: subpleural blebs only develop in the context of frank lung disease.
False. Subpleural blebs can appear in healthy people at the apices due to the greater stress (from gravity) on them.
89
Histologically, what is compensatory hyperinflation?
Normal lung parenchyma can expand in response to poor aeration in adjacent alveoli. This then closes off the poorly aerated area.
90
Describe where the nerves and artery of the arm pass over the elbow.
The radial nerve passes anteriorly over the lateral epicondyle (after it travels down the posterior of the humerus), and the median nerve travels along the brachial artery on the anterior aspect of the medial epicondyle. The ulnar nerve travels on the posterior medial epicondyle.
91
What commonly causes unilateral renal atrophy?
Renal artery stenosis
92
What three cancers of the lung appear on the periphery?
* Large cell carcinoma
* Adenocarcinoma
* Mesothelioma (not a lung parenchymal tumor but appears on the periphery of the lung)
93
Large cell carcinoma of the lung has what two associations?
* Galactorrhea
| * Gynecomastia
94
6-mercaptopurine is activated by _____________ and inactivated by _______________.
6-thioguanine is activated by ______________ and inactivated by _______________.
HGPRT; xanthine oxidase (like the nun with the 6MP necklace)
HGPRT; thiopurine methyltransferase (TPMT)
95
What cardiac pathology causes head bobbing?
Aortic regurgitation that causes a widened pulse pressure
96
__________________ is a common cause of the flattened deltoid sign.
Anterior dislocation of the humerus with interruption of the axillary nerve
97
Beta-blockers can aggravate ________________.
asthma in COPD (from block of beta-2 receptors)
98
True or false: ARPKD presents with atrophic kidneys in newborns.
False. It presents with renomegaly from cyst expansion.
99
Mutations in ____________ lead to ARPKD which is found in which two tissues?
fibrocystin
renal tubules and bile duct (so ARPKD presents with dilation of both structures)
100
What is the difference between antisocial personality disorder and paranoid personality disorder?
Paranoid personality disorder is predominately characterized by distrust of others, delusions of persecution of manipulation, and fear that others are taking advantage of them.
Antisocial personality disorder is characterized by disregard of others and violation of others' rights/boundaries.
101
What is the advantage of the conjugated pneumococcal vaccine?
It induces a robust B and T cell response, whereas the polysaccharide (non-conjugated) vaccine just stimulates B cell immunity.
102
The _______________ pneumococcal vaccine is more effective in children and the elderly.
conjugated
| which is conjugated to diphtheriae toxin
103
If someone has iron or cobalamin deficiency, how long will it take for their reticulocytes to rise following supplementation of the deficient micronutrient?
Reticulocyte count peaks in one week
104
Describe the differences between fast-twitch and slow-twitch muscles.
* Fast-twitch: the large muscle groups that are designed for rapid forceful movements; high glycogen stores for anaerobic metabolism; more common in limbs
* Slow-twitch: muscle groups designed for consistent, prolonged movements; low glycogen stores because anaerobic metabolism is not as important; myoglobin and mitochondria-rich; postural muscles more prevalent
105
The most common cause of appendicitis is ____________.
lumen obstruction by fecaliths
106
S-100 is analogous to what other protein?
Calmodulin
107
Phosphorylation of PIP2 leads to _____________.
PIP3 which activates Akt. Akt activates mTOR which is a nuclear growth factor receptor
108
What does PTEN do?
Phosphatase and tensin homolog (PTEN) removes a phosphate from PIP3 and thus disrupts the mTOR pathway.
109
What drug inhibits the mTOR pathway?
Sirolimus
110
______________ can prevent the renal side effects of acyclovir.
Aggressive hydration (which dilutes the urine and prevents the crystalluria which can accompany acyclovir treatment)
111
The crista terminalis separates the __________________.
smooth atrial muscle from the trabeculated muscle
112
Clots often form in the atrial ______________.
appendages
113
Compare POS, PPO, and HMO plans.
* HMOs have the cheapest monthly premiums but have limited provider choices and patients must see a PCP before seeing a specialist.
* PPOs have a wide provider network and don't require PCP referral for specialist visits but have expensive monthly premiums.
* Point-of-service plans have limited provider networks, but they are more expensive than HMOs because patients can go out of network.
114
What is the overall function of the Golgi tendon organ?
It senses muscle contraction because it is in series with the muscle fibers and it sends inhibitory signals when the muscle tension is too great.
115
True or false: the gingival hyperplasia seen in phenytoin use is permanent.
False. It is temporary due to upregulation of PDGF and recedes with discontinuation of phenytoin.
116
Describe the pathogenesis of gallstone ileus.
Extremely large gallstones can induce fistula formation between the gallbladder and the duodenum. Then, gallstones greater than 2.5 cm can pass into the intestines. They typically travel through the small intestines to the smallest portion: the ileocecal valve (hence the name "gallstone ILEUS"). This leads to abdominal distension and air in the biliary tree.
117
What are some physical exam signs of hypertrophic cardiomyopathy?
* Strong apical impulse
| * Crescendo-decrescendo murmur that becomes worse with standing up
118
Using labs, how can you differentiate between ornithine transcarbamylase deficiency, carbamoyl phosphate synthase deficiency, and N-acetylglutamate deficiency?
All three disorders present with hyperammonemia because the urea cycle is not working. In ornithine transcarbamylase deficiency, however, there will be a buildup of orotic acid which is what carbamoyl phosphate can get converted to. In the other two diseases, carbamoyl phosphate does not get synthesized and so orotic acid will be low.
119
True or false: ornithine transcarbamylase deficiency is usually fatal by one year of age.
False. It can go undiagnosed for years.
120
Explain diabetic mononeuropathy with the classic presentation.
Diabetic neuropathy is caused by the occlusion of small blood vessels that supply nerves, leading to nerve ischemia. In the classic presentation of CN III mononeuropathy, the motor functions are disrupted but the parasympathetic functions are intact because the PS axons travel along the outside and are less susceptible to ischemic damage.
121
Excessive kneeling can lead to ________________ bursitis.
prepatellar
122
What are Baker cysts?
Swelling of the gastrocnemius or semimebranosus bursa
123
What causes mitral stenosis?
Rheumatic fever (99% of cases!!)
124
Explain the pathogenesis of renal osteodystrophy.
Importantly, ROD is caused by two things: decreased synthesis of vitamin D and decreased excretion of PO4. The decreased vitamin D leads to decreased calcium absorption and the increase PO4 leads to the secretion of PTH which demineralizes bone.
125
Which proteins are anterograde and retrograde tubulin transport?
Kinesin: anterograde ("kicking kinesin")
Dynein: retrograde ("demur dynein")
126
True or false: a "red neuron" (highly eosinophilic cytoplasm) indicates normal apoptotic growth.
False. Red neurons indicate irreversible damage.
127
What is the classic histologic description of the endometrium under the effects of progesterone?
Dilated, coiled endometrial glands with edematous, vascularized stroma
128
Although pregnancy after permanent sterilization is rare, if it occurs there is a higher risk of ______________.
ectopic pregnancy
129
How do noncompetitive antagonists affect the Km?
They don't – Km remains the same in noncompetitive antagonists.
130
They might try to trick you by using what synonyms for precision and accuracy?
Precision: reliability
Accuracy: validity
131
What human molecule is an RNA-dependent DNA polymerase?
Telomerase (because it uses the RNA primer as a template and tags
132
True or false: friends of the patient should never be used as surrogate decision makers.
False. If a patient cannot provide consent to a procedure, then the physician should try to contact their immediate family: children, siblings, spouse, or parents. If the patient has no family, then a close friend may be used.
133
What is the best indicator of renal blood flow? (Provide the formula, too.)
Para aminohippuric acid (PAH) is the best indication of renal blood flow.
To calculate flow, divide urine [PAH] by serum [PAH] and then multiply by urine production:
(urine [PAH]) / (serum [PAH]) x urine production rate
Note: this gives the amount of serum that is filtered. To determine the RBF, divide by (1 - hematocrit).
134
What are the symptoms of reactive arthritis?
* Arthritis
* Conjunctivitis / uveitis
* Urethritis (usually preceding)
* Vesicular rash on hands and feet (keratoderma blenorrhagicum)
135
Why are two exposures needed for IgE-mediated anaphylaxis?
B cells must be exposed to the antigen and see IL-4 to isotype switch.
136
What molecule mediates the flushing reaction seen in administration of niacin?
Prostaglandins (not serotonin!)
Note: this flushing reaction can be limited with aspirin use prior to niacin intake.
(Think of the Sketchy scene: the PRO-Slugger batter is on the Niacin monster and there are two guys trying to extinguish her furnace with fire extinguishers.)
137
What histologic sign is suggestive of abetalipoproteinemia?
The enterocytes normally package dietary fats into chylomicrons around a single beta-lipoprotein. In the absence of lipoprotein B, fats accumulate in the enterocytes and lead to clear, foamy cytoplasm that is worst in the tips.
138
_____________ alveoli are more likely to collapse.
Smaller
139
Explain how the E. coli lac operon works.
• All of the genes needed to metabolize lactose are structured together in a group.
• Upstream (in the 5' direction) of them are four important regulatory sites:
(1) lac I gene – which is constitutively expressing an inhibitor of the lac operon
(2) Catabolite activator protein – which stimulates transcription of the lac operon when glucose levels are low and cAMP levels are high
(3) lac P: the RNA polymerase binding site
(4) the lac operator
The lac operator locus binds to the lac I inhibitor and prevents RNA polymerase from transcribing the lac operon. When lactose levels are high, lactose binds to lac I and changes its conformation. Thus, the operator locus is no longer inhibiting transcription.
140
_______________ causes right-sided heart murmurs to get louder and left-sided heart murmures to get softer.
Inspiration
141
Standing and Valsalva straining increase which murmurs?
Mitral valve prolapse and hypertrophic cardiomyopathy (all other murmurs decrease)
Note: squatting will cause MVP and HCM to decrease
142
What landmark is used for lumbar puncture?
Needles in lumbar punctures are inserted in the L3/L4 or L4/L5 space which is roughly at the height of the top part of the iliac crest.
143
True or false: viral meningitis presents with normal protein levels in the CSF.
False. Protein is typically elevated.
| Think of the Sketchy scene with the "Source of Protein" food bag for the aviary.
144
Patients with Klinefelter syndrome do not have __________ cells.
Sertoli (Leydig cells are also dysfunctional)
As a result of Leydig and Sertoli dysfunction, LH and FSH are high.
145
What causes familial hypercalcemic hypocalciuria?
Defects in the parathyroid and renal sensing of calcium levels
As such, parathyroid and calcium will be high. Little calcium is excreted because the kidneys also can't sense calcium levels and absorb too much.
146
What's the difference between capitation adn global payment?
Capitation is a plan in which a recurring fee to a physician group covers all costs. Global payment is a single payment for one medical event such as a surgery.
147
What part of the bone is stimulated to mature by estrogen?
The epiphyseal plate
148
True or false: gasses with higher blood/gas partition coefficients (those that are more soluble in blood) require longer to take effect and longer to saturated the blood.
True. It's a little counterintuitive that a more blood-soluble gas takes longer to saturated the blood, but think of this: the more soluble it is, the more gas needs to be given to fill the blood.
149
Which inhaled anesthetic is more soluble, halothane or NO?
The fluorinated anesthetics (like halothane) are more soluble, meaning they have a higher blood/gas partition coefficient. As such, they are slower to induce anesthesia and take longer to wear off.
(Think of the Sketchy scene: the kid who's running through the ball pit – representing the partition coefficient – represents halothane. The kid who passed out on the edge represents NO which has a low blood/gas partition coefficient.)
150
How does hereditary spherocytosis affect MCV and MCHC?
This is tricky: in HS, little blebs of RBC membrane break off due to the defective cytoskeleton. As such MCV remains normal or goes down even though the reticulocyte count is high and should make the MCV greater than normal. Secondly, because the spherocytes lose volume when the blebs break off, the MCHC increases! In fact, increased MCHC is very specific to HS.
151
Describe hypoxic-ischemic encephalopathy.
There are watershed areas in the brain between the three main cerebral arteries. The areas are parallel to the interhemispheric fissure and roughly wedge-shaped. In a person with shock (such as from a prolonged arrhythmic episode), ischemia can damage the brain and lead to stripes of tissue necrosis in these watershed areas.
152
How will hypertensive encephalopathy present on MRI?
With cerebral edema and petechial hemorrhages
153
Patients with what co-morbidity are likely to be greatly impacted by atrial fibrillation?
Aortic stenosis!
In patients with AS, the left ventricle becomes hypertrophied. As a result, it is less able to expand during diastole. Because of this, it is dependent upon the contraction of the left atrium for diastolic filling. If atrial fibrillation develops, then the atrium is not contracting and the left ventricle will not fill.
154
What autosomal dominant condition results in high LDL?
Heterozygous familial hypercholesterolemia – a defect in the LDL receptor
(Homozygous individuals often die of atherosclerotic disease in childhood.)
155
Imprinting enzymes use what molecule as a donor?
S-adenosyl methionine (SAM)
156
A question is asking what kind of mutation led to a certain molecular abnormality. How can you definitively differentiate between nonsense mutations and frameshift deletions?
Frameshift mutations shorten DNA, while nonsense mutations do not shorten DNA. Nonsense mutations only shorten the translated protein!
157
What are Langerhans giant cells?
Multinuclear macrophages found in granulomas
Noticeably, their nuclei form a round, horseshoe-shaped ring around the periphery of the cytoplasm.
158
How likely is it that an HBV-positive mother will transmit HBV to her child?
If the mother is HBeAg-positive around the time of delivery, then there is a greater than 90% chance that the baby will have HBV.
159
How soon will infants be positive for HBeAg from perinatal infection with HBV?
Within days/weeks
160
What artery supplies the internal capsule?
The anterior choroidal artery (posteriorly) and the ACA (anteriorly)
161
The __________________ arteries supply the basal ganglia?
deep branches of the middle cerebral
162
Which artery supplies the thalamus?
The PCA
163
A schizophrenic episode lasting less than one month is referred to as ____________.
a brief psychotic episode
164
How is flow proportional to the radius of a lumen?
Flow -> 1/(r^4)
So if the radius goes down by 1/2, then the flow decreases to 1/16.
165
What nerves mediate submandibular secretions?
Lingual nerve from CN VII
166
What does the glossopharyngeal nerve do?
It innervates the sensation of the posterior pharynx and tonsils (part of the gag reflex) and sensation and taste of the posterior 1/3 of the tongue.
167
The suspensory ligament of the ovary is also called the _________________.
infundibulopelvic ligament
168
What is the main risk factor for ovarian torsion?
Ovarian cysts/masses
169
The __________ gives rise to Rathke's pouch, while ________________ gives rise to the branchial arches.
surface ectoderm; neural crest
170
Those with obstructive lung diseases do more respiratory work at _____________, while those with restrictive lung diseases do more work at _______________.
high RR; high TV
This is why those with COPD have prolonged expiratory phases (and thus low RRs).
171
In terms of hospital sanitation, what is the difference between droplet and respiratory precautions?
Droplet precautions are for organisms that travel by respiratory droplets (like Neisseria or RSV) and require a facemask, while respiratory precautions are for respiratory organisms like TB or influenza and only require a mask.
172
Explain the cellular pathogenesis of COPD.
Smoking irritates the airways and activates alveolar macrophages. The activated macrophages recruit neutrophils and CD8 cells which destroy the alveoli. Neutrophils are the main destructive cells.
173
What is the defense mechanism of "undoing"?
Mentally or symbolically nullifying an unacceptable thought or action such as by repentance or ritual (common in OCD)
174
Trihexyphenidyl can alleviate which of the Parkinson's symptoms?
Tremor and rigidity (like the trembling car in the background of the Sketchy scene) but NOT bradykinesia (which it why the car is not moving)
175
In general, carbiodpa alleviates the _____________ effects of levodopa but worsens the ____________ effects.
peripheral (hypotension, nausea, arrhythmia); central (anxiety, agitation)
176
What drug is often used restless leg syndrome?
Dopamine agonists such as pramipexole and ropinarole
177
Trace the protein interactions needed for rolling, adhesion, crawling, and transmigration.
* Rolling: L-selectin on neutrophil to E/P-selectin on endothelial cell
* Adhesion and crawling: CD18 on neutrophil to ICAM on endothelium
* Transmigration: PECAM (they PEEK through the endothelium)
178
Which muscarinic receptor mediates most of the effects of acetylcholine in the PNS?
M3
M1: brain
M2 heart
M3: gut, eye, bladder, skin, lungs, peripheral vasculature
179
At FRC the intrapleural pressure is roughly ____________. During inspiration it can go to _________.
- 5 cm H2O; - 7.5 cm H2O
180
Colchicine works the same way as ___________.
vincristINE (they both end in INE)
181
Colchicine can cause _______________.
intractable nausea and diarrhea (like the diarrhea being tracked into the church by the first responders)
182
Describe the sensory innervation of the ear.
Most of the external ear is innervated by CN V (anterior), great auricular from C2 and C3 (inferior), and lesser occipital from C2 and C3 (posterior). However, the external auditory canal and the meatus are innervated by the vagus nerve and the trigeminal nerve. As such, vasovagal responses can happen with otoscopy.
183
Paroxysmal nocturnal hematuria can lead to renal damage by which mechanism?
Hemosiderosis from iron deposition in the tubules
184
A histologic section of necrotic brain tissue has been stained for lipids. What cells might have abundant staining in their cytoplasm?
Microglia – they'll be ingesting lipids degraded from oligodendrocytes
185
Explain the synthesis of collagen and the most common type of Ehlers-Danlos.
* Collagen is translated in the cytoplasm
* Signal-recognition particle directs translation to the endoplasmic reticulum
* SRP is cleaved
* Collagen is hydroxylated and glycosylated
* Triple helix assembles
* Collagen is secreted by the Golgi apparatus
* Procollagen peptidase cleaves the N- and C-terminal ends
* Triple helices are crosslinked
The most common form of Ehlers-Danlos results from defective procollagen peptidase which leads to impaired cross-linking of the triple helices.
186
What are key features of ecological studies?
Ecological studies (1) deal with populations, not individuals and (2) only examine associations and correlations. They should only be done to generate hypotheses, not support conclusions.
187
What gene accounts for the height loss in girls with Turner syndrome?
The SHOX gene (SHOX = SHOrt)
188
True or false: Wiskott-Aldrich syndrome results from defective IL-17.
False. Wiskott-Aldrich is an X-linked disorder that is caused by defective B and T cells. Job syndrome results from defect IL-17 signaling. ("You get your first JOB at 17.")
189
How does Cryptococcus get to the brain?
Via the lungs (not the nasopharynx!!!)
190
The most common disorder of fatty acid metabolism is ________________.
MCAD deficiency
(medium-chain acyl CoA dehydrogenase)
This presents with hypoglycemia and absence of ketones after more than ~15 hours of fasting.
191
Citrate increases the function of __________________.
acetyl CoA carboxylase (which produces malonyl-CoA – first step in fatty acid synthesis)
192
Differentiate bulimia nervosa from anorexia nervosa with binging/purging.
BN is characterized by binging and purging with normal body weight. AN with binging and purging is characterized by the same but with BMI less than 18.5 and signs of starvation.
193
Pulmonary vascular resistance is lowest at ________________.
FRC
194
The _________________ fascia is posterior to the esophagus and leads down into the mediastinum.
buccopharyngeal
195
Epiglottitis causes ________________ stridor.
inspiratory
196
The bacterium that has a capsule made from polyribosylribitol phosphate (PRP) most commonly causes _______________ in unvaccinated children.
epiglottitis (being H. influenza)
197
Which pathogen has protein A as a virulence factor?
S. aureus (Moses' stick)
198
_________________ uses lecithinase to hydrolyze lecithin in cell membranes.
C. perfringens
Lecinithinase is also called toxin A.
199
The S3 heart sound is best heard by __________________________.
having the patient in the left lateral decubitus position, over the apex, using the bell, at end expiration (which moves the heart closer to the chest wall)
200
The _______________ geniculate nucleus processes visual information.
lateral
| Remember, the MEdial geniculate nucleus processes information from the auditory MEatus.
201
Explain the ethics of dating patients.
* It is always unethical to date a patient whose psychiatric care you have provided.
* Physicians may date patients so long as the physician-patient relationship has been terminated well before BY THE PATIENT. For instance, if a patient expresses romantic interest in a doctor, that doctor should not tell the patient that they need to terminate the medical relationship so that they can date because that tells the patient that they should terminate their medical care, which is inappropriate.
202
Mucicarmine stain will cause C. neoformans to show up as __________________.
dots with thick red capsules around
203
Arthralgia, liver disease, and diabetes indicate ________________.
hereditary hemochromatosis (also bronzing of the skin)
204
Explain the difference between intrapulmonary shunting and collateral circulation in the lungs.
Collateral circulation refers to the dual blood supply of the lungs: the pulmonary artery and the bronchial artery. This prevents necrosis during pulmonary embolism.
Intrapulmonary shunting refers to the constriction of pulmonary vessels when ventilation is inadequate. That is, vessels not being oxygenated will constrict and shunt blood to more oxygenated areas.
205
Untreated prolactinomas can lead to increased risk of _______________________.
fractures (because of decreased estrogen)
206
__________________ can cause inflammatory diarrhea and macular rash on the abdomen.
Salmonella typhi
207
TSH binds to a _________________ receptor.
G-protein coupled
208
Which antimicrobial drug is a glycopeptide?
Vancomycin
209
Which lab finding will be seen in lead poisoning, basophilic stippling or ring sideroblasts?
Trick question: both can be seen, but ring sideroblasts are only seen in bone marrow aspirates because that is where heme synthesis takes place. Mitochondria will dissolve in RBCs before they leave the marrow and thus not appear in a peripheral blood smear. Basophilic stippling, however, can be present in a peripheral blood smear because that is a different mechanism. Stippling is failed disaggregation of ribosomes (also inhibited by lead), and can present in RBCs inthe periphery.
210
In addition to defying parental requests and arguing excessively, oppositional defiant disorder usually presents with what other symptoms?
* Vindictiveness
* Frequently annoying others
* Blaming failures on other people
* Extreme anger
211
True or false: Ghon complexes indicate secondary tuberculosis that has been cleared.
False. Ghon complexes (fibrotic foci and calcified lymph nodes) occur with primary TB infection.
212
True or false: a postmenopausal woman with hypocalcemia should take alendronate to lessen osteoporosis.
False. Alendronate prevents osteoclast activation, but it can worsen hypocalcemia so this is contraindicated in hypocalcemia.
213
What is cinacalcet used for?
It is a calci-mimetic that tricks the calcium receptors in the parathyroid glands into thinking the calcium concentration is higher than it is. It is given to those with hyperparathyroidism to dampen the release of PTH.
("Cinacalcet = Cinacalcimimetic")
214
Describe the mechanism and contraindication of sevelamer.
Sevelamer is a non-absorbed phosphate binder that is used to decrease phosphate absorption in dialysis patients.
215
Potassium permeability is greatest during ________________.
repolarization (steep slope)
216
Which antiretroviral can cause a flu-like illness?
NNRTIs
217
Explain how free fatty acids contribute to the pathogenesis of T2DM.
Insulin, you'll recall, induces anabolic growth in adipocytes. Resistance to insulin in adipocytes thus leads to decreased triglyceride synthesis and increased fatty acid release. The fatty acids then go to the liver and contribute to gluconeogenesis.
218
Colonic adenomas usually start with _______________ mutations.
APC
Then KRAS and finally p53.
219
Von Hippel-Lindau disease presents with increased risk of hemangioblastomas in the retina and cerebellum, RCC, and ____________.
cysts in the liver, kidney, and pancreas
