UWorld Practice Questions #1 Flashcards
(450 cards)
1
Q
What are the two classes of Ca channel blockers and how do their effects differ?
A
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.
2
Q
What is the complement component that is deposited in glomeruli in PSGN?
A
C3. Note that the pts will have decreased levels of C3, IgG and IgM due to immune complex deposition.
3
Q
What do patients with tetralogy of fallot squat when they become cyanotic?
A
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.
4
Q
What is the major determinant of the ratio of forward to reverse flow in mitral regurgitation (i.e. mitral valve prolapse)?
A
L ventricular afterload. The lower it is, the higher that ratio will be.
5
Q
What is first line treatment for trigeminal neuralgia? What is the mechanism of action?
A
Carbamazepine. It works by blocking Na channels.
One ADR is bone marrow suppression.
6
Q
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?
A
Pyruvate dehydrogenase (forming acetyl CoA from pyruvate) and alpha-ketoglutarate dehydrogenase complex (froming succinyl CoA from alpha-ketoglutarate) are both thiamine dependent.
7
Q
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
A
L side –> apathy and depression
R side –> disinhibition
8
Q
How can one make the clinical dx of narcolepsy?
A
Decreased levels of hypocretin-1 in the CSF or shortened REM onset latency on sleep study.
9
Q
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?
A
Low potency ones. Higher potency ones are more likely to cause the extra-pyramidal sxs that can be seen.
10
Q
What are two examples of true diverticulum (involve mucosa, submucosa and muscularis layers)? How about false diverticulum (involve just mucosa and submucosa)?
A
True –> Meckel’s diverticulum, the appendix
False –> Zenker diverticulum, diverticulosis.
11
Q
Hepatitis B has a proliferative phase and an integrative phase. Describe what is occurring during each:
A
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.
12
Q
Why is lowering PaCO2 (i.e. by adjusting the ventilator settings) sometimes employed in the treatment of diffuse cerebral edema?
A
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.
13
Q
What are the mechanisms of DNA damage from ionizing radiation used therapeutically?
A
One is double stranded DNA breaks. The other is generation of oxygen free radicals which damage DNA and cells.
14
Q
What is the trinucleotide repeat in fragile X?
A
CGG on FMR1 gene
15
Q
In the citric acid cycle, which enzymes use NAD as a cofactor and which one uses FAD as a cofactor?
A
NAD –> isocitrate dehydrogenase and alpha-ketoglutarate dehydrogenase complex.
FAD –> succinate dehydrogenase.
16
Q
In which populations of patients is exagerated hyperthermia a concern for with administration of succinylcholine?
A
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.
17
Q
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
A
- 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
18
Q
What sorts of things are primarily made up of type 1 collagen?
A
dermis, bone, tendons, ligaments, dentin, cornea, blood vessels, and scar tissue.
19
Q
What is the embryologic pathogenesis that produces transposition of the great vessels?
A
Instead of the aorticopulmonary septum developing spirally, it develops linearly.
20
Q
What sort of arrhythmia medications have constipation as a common side effect?
A
Non-dihydropyridine CCBs (verapamil > dilatazem)
21
Q
Where in the brain is vomiting from chemotherapy induced?
A
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.
22
Q
What is the name of the drug that affects funny Na channels and slows heart rate w/o affecting inotropy or lusitropy?
A
Ivabradine
23
Q
What are the most common drugs that have zero order metabolism?
A
Ethanol, aspirin and phenytoin
24
Q
Which cells make major basic protein and what its function?
A
Eosinophils make MBP and it is a potent helminthotoxin.
25
What sort of epithelium are the true vocal folds made of?
Stratified squamous epithelium, which is what HPV likes to infect.
26
If left untreated, what are the signs and sxs of congenital hypothyroidism?
constipation, lethargy, hypotonia, large anterior fontanelle, macroglosia, and an umbilical hernia.
27
Deficiency of which enzyme causes muscle bx to show glycogen accumulation in the lysosomes?
Deficiency of acid-alpha glucosidase (which helps break down glycogen). This is the type II glycogen storage disease aka Pompe disease.
28
What is the marker for high infectivity for hepatitis B infection?
Presence of HBe antigen. Also having low HBeAb.
29
What is a common nerve injury that results from supracondylar fracture of the humerus?
Injury to the proximal median nerve.
30
What does the supraclavicular nerve innervate?
Supraspinatus and infraspinatus
31
What sort of autoantibodies are characteristic of pemphigus vulgaris?
anti-desmoglein 1 and 3.
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?
Polymyositis. Bx likely shows endomysial mononuclear inflammatory infiltrate and patchy muscle fiber necrosis.
33
How does obstructive and restrictive airway disease affect work of breathing at different parts?
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.
34
What is the function of thyroid peroxidase?
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.
35
Which nerve is commonly injured in a supracondylar humerus fracture w/ anterolateral displacement? How about one with anteromedial displacement?
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).
36
What is the ANOVA (analysis of variance) test used for?
To determine if there are any significant differences in the means of two or more independent groups.
37
What are the five cofactors of the branched chain dehydrogenase complex?
Thiamine, lipoate, conezyme A, FAD, NAD.
Note that some patients receive benefit from high dose thiamine supplementation.
38
In which patients is supplementation of tetrahydrobiopterin potentially beneficial? Why?
PKU patients. This is because tetrahydrobiopterin is a cofactor for phenylalanine hydroxylase and deficiency can result in phenylketonuria. Thus, supplementation can reduce phenylalanine levels.
39
What is the result of the mutation in sickle cell?
It is a point mutation in the 6th codon of the B globin gene that results in a glutamic acid to valine substitution.
40
GFR is approximately equal to the clearance of what substance?
Inulin. This is because inulin is neither excreted nor reabsorbed.
41
True or false, CN XI passes through the posterior triangle of the neck?
True!
42
What enzyme allows erythrocytes to undergo glycolysis w/o generating any net ATP?
Bisphosphoglycerate mutase. This allows conversion of 1,3-BPG to 2,3-BPG in RBCs and this is an important regulator of RBCs.
43
Where in a cell is structural RNA like ribosomal RNA produced?
In the nucleolus. It makes the different subunits for ribosomes. All except the 5s rRNA are made there.
44
What is the causative organism of fifth disease?
Parvovirus B19. This disease is characterized by the "slapped cheek" rash.
45
How does the culture of coccidiomyces vary based on temperature in terms of what you see?
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
46
What does graft versus host disease of the liver most commonly show? What disease process does this most resemble?
lymphocytic infiltration w/ destruction of intrahepatic bile ducts, causing a risk in alk phos. This most closely resembles PBC.
47
When is S3 heard best and at what position?
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.
48
What is the presentation of bloom syndrome and what is the genetic defect?
Presentation = photosensitive rash, facial anomalies, growth retardation and immunodeficiency due to chromosomal instability and breakage.
It is due to a genetic defect in helicase.
49
In most patients, which artery supplies the majority of the inferior surface of the heart?
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.
50
Which markers can be elevated (detected via amniocentesis) in neural tube defects where there is failure of the neural tube to close?
Alpha fetoprotein and acetylcholinesterase. This is because an opening persists btwn the neural tube and these things leak into the amniotic fluid.
51
Which sorts of fats are NOT oxidized in the mitochondria and instead undergo a separate oxidation process in the peroxisome?
VLCFAs and some branched chain fatty acids.
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).
Attributable risk in the percent exposed = 100 x [(RR-1)/RR]
53
What is the equation for filtration fraction using RPF and GFR?
FF = GFR/RPF
54
What does graft versus host disease of the liver most commonly show? What disease process does this most resemble?
lymphocytic invasion w/ destruction of intrahepatic bile ducts, causing a risk in alk phos. This most closely resembles PBC.
55
Which vessel supplies the rectus abdominus and enters the muscle at the level of the arcuate line?
Inferior epigastric artery and vein.
56
In a situation of hemolytic disease of the newborn with the first pregnancy, what is the likely blood type of mom and fetus?
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.
57
Define lead time bias:
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.
58
Which markers can be elevated (detected via amniocentesis) in neural tube defects where there is failure of the neural tube to close?
Alpha fetoprotein and acetylcholinesterase. This is because an opening persists btwn the neural tube and these things leak into the amniotic fluid.
59
What is a physical exam finding that can be seen in X-linked (Bruton's) agammaglobulinemia?
Absence of tonsils
60
What is seen on light microscopy in membranoproliferative glomerulonephritis? How about immunofluorescence?
light microscopy = basement mebrane splitting
immunofluorescence = granular deposits
61
What is head bobbing with carotid pulsations indicative of?
Aortic regurgitation
62
What are the derivatives of the first pharyngeal and aortic arches?
trigeminal nerve and maxillary artery (portion of it) respectively
63
What are the derivatives of the second pharyngeal and aortic arches?
facial nerve and stapedial artery (which regresses I believe) respectively
64
What are the derivatives of the third pharyngeal and aortic arches?
glossopharyngeal nerve and common carotid and proximal part of internal carotid arteries
65
What are the derivatives of the four pharyngeal and aortic arches?
superior laryngeal branch of vagus nerve and true aortic arch and subclavian arteries respectively
66
What are the derivatives of the sixth pharyngeal and aortic arches?
recurrent laryngeal branch of vagus nerve and pulmonary arteries and ductus arteriosus.
67
What is the presentation of Fabry's disease?
multiple angiokeratomas (small, reddish-black papules), acroparesthesia (intermittent peripheral paresthesias), and heat intolerance.
Caused by deficiency of alpha-galactosidase A.
68
Embryonically, where do parafollicular C cells of the thyroid originate?
In the ultimobranchial bodies
69
What does the falciform ligament do?
It attaches the liver to the anterior body wall.
70
A defect in CD18 causes what disease? What is the presentation?
It causes leukocyte adhesion deficiency. Pts present w/ delayed separation of the umbilical cord, infections w/o pus formation and poor wound healing.
71
What is the likely defect in patients that present in infancy or early childhood with disseminated mycobacterial disease?
Inherited defect in the interferon gamma signaling pathway.
72
Injury to what nerve causes a trendelenburg gait?
Superior gluteal nerve. It innervates glut med, min and TFL.
73
BRAF mutations are a RF for which thyroid cancer? How about RAS mutations?
BRAF --> papillary thyroid cancer (the one w/ orphan Annie nuclei on histo)
RAS --> follicular thyroid cancer
74
What substance accumulates in the walls of vessels in Fabry's disease?
Ceramide trihexoside
75
What is the presentation of Fabry's disease?
multiple angiokeratomas (small, reddish-black papules), acroparesthesia (intermittent peripheral paresthesias), and heat intolerance.
76
In what disease is there pathologic accumulation of galactocerebroside?
Krabbe disease
77
In what disease is there pathologic accumulation of glucocerebroside?
Gaucher disease
78
In what disease is there pathologic accumulation of sphingomyelin?
Niemann-Pick disease
79
In neurons, what is the length constant a measure of?
How far along an axon an electrical impulse can travel. This is decreased by demyelination.
80
Injury to what nerve causes a trendelenburg gait?
Superior gluteal nerve.
81
Autoantibodies against desmosomes in the skin causes what condition?
Pemphigus vulgaris
82
Autoantibodies against hemidesmosomes causes what skin condition?
Bullous pemphigoid
83
What are the function of desmosomes and hemidesmosomes respectively?
Desmosomes anchor cells to one another. Hemidesmosomes bind epithelial cells to the basement membrane below them.
84
What are the histological findings of chronic bronchitis?
Thickened bronchial walls, lymphoctic infiltrate, mucus gland enlargement, and patchy squamous cell metaplasia.
Cigarette smoking is the leading cause.
85
If a patient has gastric varices of the fundus, which vein do you expect to be occluded or have increased pressure?
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.
86
What enzyme does insulin signaling act thru in order to increase glycogen synthase?
A protein phosphatase that removes a P from glycogen synthase in order to activate it.
87
Why does nitroprusside decrease both preload and afterload?
Because it is a balanced vasodilator and dilates both arteries and veins.
88
What makes up an MHC class 1 molecule
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.
89
Where does the umbilical vein drain into? Via what structure?
It drains into the IVC of the fetus via the ductus venosus.
90
What is the adult remnant of the umbilical vein?
The ligamentum teres.
91
What is a Cheyne-Strokes breathing pattern? In which patients is it seen?
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.
92
What chromosome and arm is the VHL gene on?
3p
93
Why can patients with selective IgA deficiency have transfusion reactions?
Because they can form IgE against IgA that triggers uticaria, edema and wheezing upon receipt of blood products containing IgA.
94
What are medications that are used to treat lead poisoning?
EDTA and dimercaprol
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?
alpha-intercalated cells promote K+ resporption and principal cells promote K+ secretion.
96
What causes annular pancreas?
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.
97
What are the last 2 vessels a thrombus traverses before lodging in the retinal artery and causing acute, painless, mono-ocular vision loss?
Internal carotid --> ophthalmic --> retinal
98
What enzyme is the rate limiting step of bile acid salt synthesis from cholesterol? Name a medication that inhibits this enzyme.
Cholesterol 7alpha hydroxylase. Fibrates inhibit it.
99
Heme synthesis has to occur in a couple areas of the RBC in order to happen completely. What are these two areas?
cytoplasm and mitochondria.
Mito needed for first step and final 3 steps.
100
IL-4 promotes B cell isotype switching to what isotype?
IgE
101
IL-5 promotes B cell isotype switching to what isotype?
IgA
102
What is necessary in order to determine that a patient has the capacity to refuse treatment?
ability to express a choice, understand relevant medical info, appreciate consequences of treatment options, and offer a rationale for the decision.
103
During what interval of fetal development does the yolk sac make RBCs?
weeks 3-8 of fetal development
104
When do the liver and spleen make RBCs in fetal development?
Liver --> 6 weeks until birth
| Spleen --> weeks 10-28 of fetal development
105
What area of the anterior spinal cord does the artery of adamkiewicz supply?
The bottom 2/3. Usually starting around the level of T8.
106
What are the lab findings in osteitis fibrosa cystica?
elevated Ca++, alk phos and PTH. Low levels of P. Results from chronic hyperparathyroidism.
107
What is the most common cause of neonatal meningitis?
GBS (aka streptococcus agalactiae)
108
What causes progressive multifocal leukoencephalopathy and what is seen on flair MRI?
JC virus. Non-enhancing areas of demyelination on MRI.
109
In an upright person, ventilation _______ from the apex to the base?
Increases.
110
What gene is mutated in ARPKD?
PHKD1 which codes for fibrocystin.
111
Which artery is the middle meningeal artery a branch of?
Maxillary artery
112
Why does silicosis place patients at increased risk for TB?
Because silica ingestion by macrophages disrupts their function and can even cause them to release viable mycobacteria.
113
What is the mechanism of sirolimus?
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.
114
What sort of dysfunction does dilated cardiomyopathy cause?
Systolic dysfunction. Causes HFrEF.
115
What sort of dysfunction do restrictive cardiomyopathies cause?
diastolic dysfunction - HFpEF.
116
What is transthyretin and what can it be a part of in terms of cardiac pathology?
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.
117
Why use glucocorticoids in a neonate that is experiencing NRDS?
Because corticosteroids promote surfactant production by accelerating the maturation of type II pneumocytes.
118
What enzyme is deficient in PKU?
phenylalanine hydroxylase
119
What are the brain findings on autopsy of PKU patients?
hypopigmentation of cholinergic brain centers which are the substantia nigra, the locus ceruleus, and the vagal nucleus dorsalis.
120
What enzyme is most commonly depressed or absent in albinism?
Most commonly tyrosinase. This is because melanin synthesis relies on this enzyme.
121
What is the mechanism of sirolimus?
It is a proliferation signal inhibitor that works by targeting the mTOR pathway. Specifically, it interupts IL-2 signal transduction.
122
What is the mechanism of bortezomib?
Binds the 26S proteasome.
123
What is the mechanism of mycophenolate?
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.
124
What causes a patent foramen ovale?
Incomplete fusion of the septum primum and secundum.
125
What is the unique location and role of the H1 histone protein?
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.
126
What auscultation finding is associated w/ PDA?
Continuous murmur heard best at the L sternal border.
127
Under what conditions is pigment stone formation promoted in the gall bladder?
In instances of increased unconjugated bilirubin (hemolysis, secondary to infection by stuff like the helminth C. sinensis).
128
True or false, Candida albicans is a germ-tube negative fungus.
False! It is a germ-tube positive fungus
129
What serological markers are present during the window period of HBV infection?
Only anti-Hbe and anti-Hbc IgM are present.
130
What are the first and second most common causes of impetigo?
```
First = S. aureus
Second = GAS.
```
131
How does giardia infection lead to diarrhea?
It caused small bowel inflammation (loss of brunch border enzymes) and villous atrophy leading to malabsorption and atrophy.
132
What is the first line treatment for pan-susceptible enterococcus infection?
ampicillin
133
What are the HACEK organisms (those that cause culture negative endocarditis)?
Haemophilus spp., Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae.
134
What media are typically used for growth and isolation of diptheria?
Typically Loeffler medium and tellurite agar are used in conjunction for the diagnosis of C. diptheriae infection.
135
What agar is used to culture pertussis?
Bordet-Gengou agar is used to culture Bordetella pertussis. Regan-Lowe medium can be used too (this is more common today).
136
What is pathognomonic on bronchoalveolar lavage for PJP injection?
foamy alveolar casts.
137
In what direction is blood normally shunted in tetralogy of fallot?
R to L shunt
138
What part of the brain initiates conjugate horizontal gaze?
The frontal eye field in the cerebral cortex.
139
What causes an umbilical hernia?
Incomplete closure of the umbilical ring.
140
Where in the CNS are seratonergic (seratonin releasing) neurons primarily found?
In the Raphe nuclei in the brainstem.
141
Where is the locus ceruleus and what does it house?
It is in the dorsal pons and it houses the noradrenergic (norepi releasing neurons) that contribute to fight or flight response.
142
What does the nucleus of Meynert house?
The cell bodies of acetylcholine releasing neurons.
143
What is riboflavin (B2 vitamin) a precursor for? As such, what enzymatic reaction is is a cofactor in?
Precursor for FAD and FMN. FAD is a cofactor in the succinate dehydrogenase reaction in the TCA cycle.
144
Histone acetylation ________ DNA transcription
enhances
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?
Echinococcus granulosus (a parasitic tapeworm transmitted by dog feces). Albendazole is medical therapy.
146
What is the most common cause of pneumonia in CF pts under 20? Over 20?
< 20 --> S. aureus
| > 20 --> pseudomonas
147
What is a complication of CMV retinitis?
Retinal detachment
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?
Proximal hair cells --> high freq loss
Distal hair cells --> low freq loss
149
Basal cell carcinoma is more commonly seen on the ______ lip, whereas squamous cell carcinomas are more commonly seen on the ______ lip.
Basal --> upper
Squamous --> lower
150
What is the pre-malignant lesion for squamous cell carcinoma?
Actinic keratosis.
151
What sort of diuretic medical management is indicated in an acute CHF exacerbation?
Furosemide
152
What sort of kidney stones are hexagonal?
Cysteine stones (pts often have defects in amino acid resorption in the proximal tubule).
153
Which H2 blocker used for tx of PUD can cause decreased libido and gynecomastia?
Cimetidine
Note that ranitidine has the same mechanism of action but lacks the anti-androgenergic side effects.
154
What condition is temporal arteritis associated with?
Polymyalgia rheumatica
155
What cardiac defect is Friedriech Ataxia associated with?
Hypertrophic cardiomyopathy
156
Acute hemolytic transfusion reactions represent what type of hypersensitivity reaction?
Type II
157
What mediators cause the vasodilation and shock sxs in acute hemolytic transfusion reaction? How about the cell lysis?
Shock --> C3a and C5a causing vasodilation
lysis --> C5b-C9
158
What does the metyrapone stimulation test look at?
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.
159
Puncture of the femoral artery superior to the inguinal ligament is likely to lead to bleeding in what space?
The retroperitoneal space as the external iliac artery courses just inferior to the peritoneum.
160
What molecule/signal activates mTOR to translocate to the nucleus? Which one inhibits mTOR?
Protein kinase B aka Akt activates mTOR
PTEN inhibits mTOR
161
True or false, enterococcus is part of the normal urogenital flora?
True! Why manipulation of these areas (i.e. cytoscopy) can cause still like enterococcus endocarditis.
162
What foramen is traversed as CSF moves from the lateral to third ventricle?
Interventricular foramina of monro
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?
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.
164
How strong is "prior attempt" as a risk factor for suicide?
Strong! In fact it is the strongest RF! Patients w/ a prior attempt are 5-6x more likely to attempt again.
165
What is the clinical presentation of a patient w/ galactose-1-P uridyl transferase deficiency?
Jaundice, hepatomegaly, vomiting, renal dysfunction, E. coli sepsis, cataract, hemolytic anemia.
166
In 5' to 3' direction, what are the 3 mRNA stop codons?
UAA, UAG and UGA
167
What is a normal A-a gradient in healthy individuals?
5-15 mmHg
168
What are the four major causes of hypoxemia (aka low PaO2)?
Alveolar hypoventilation, R to L shunt, diffusion impairment, V/Q mismatch.
169
What is the presentation of I-cell disease?
course facial features, clouded corneas, restricted joint movement, high plasma levels of lysosomal enzymes,
170
What is the mechanistic defect in I-cell disease?
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.
171
What vitamin is a cofactor for α-ketoglutarate dehydrogenase, pyruvate dehydrogenase, and transketolase?
Thiamine (B1)
172
What is the most specific test w/ which to dx syphilis?
The fluorescent treponemal antibody absorption (FTA-ABS) test is the most specific serologic test for syphilis
173
Where is oxytocin stored?
In the posterior pituitary! It is made in the hypothalamus but NOT stored there.
174
What is the pathophysiology of globozoospermia?
The Golgi apparatus is not transformed into the acrosome, resulting in male infertility.
175
What is a shared ADR of the anti-thyroid medications methimazole and propylthiouracil?
They both can cause agranulocytosis (presentation is commonly sudden onset fever and sore throat).
176
What is the common presentation of acute intermittent porphyria?
Neuro sxs (tingling, difficulty concentrating), recurrent episodes of non-specific abdominal pain, port-colored wine.
177
What is the treatment of acute intermittent prophyria? What enzyme does treatment down-regulate?
Infusion of hemin (a heme preparation). Down-regulates ALA-synthase.
178
Of cellular swelling, mitochondrial vacuolization, and nuclear shrinkage (pyknosis), fragmentation and dissolution, which is considered reversible cell injury?
Cellular swelling. The other two are (mito and nuclear changes) are considered irreversible cell injury.
179
What innervates the cricothyroid muscle?
External branch of the laryngeal nerve
180
What does the cricothyroid muscle do?
It acts to tense the vocal cords. Denervation may cause a low, hoarse voice.
181
What defines isolated systolic hypertension (ISH)? What causes it?
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.
182
What embryologic layer is the spleen derived from?
Mesoderm. This is unique b/c most of the rest of the GI tract (liver, pancreas, intestines, etc.) are derived from endoderm.
183
What is PD-1 and what is its relation to cancer evasion of the immune system?
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.
184
Why can injury to the facial nerve cause ear pain?
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.
185
What is the initial step in the pathogenesis of atherosclerosis?
Endothelial cell injury --> this leads to increased permeability and monocyte and lymphocyte adhesion and invasion.
186
What is pulsus paradoxus?
It is where there is a decrease in systolic BP > 10 mmHg upon inspiration.
187
For which cardiac pathology is this murmur classic for: opening snap followed by a diastolic rumbling murmur?
mitral stenosis
188
What is the Hawthorne effect?
The tendency of study subjects to change their behavior once they know that they are being observed.
189
What is Berkson's bias?
Selection bias created by choosing hospitalized patients as the control group.
190
What is the Pygmalion effect?
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).
191
What is the equation for half-life that uses clearance (CL) and volume of distribution (Vd)?
T1/2 = (0.7 x Vd) / CL
192
How does biotin (vitamin B7) deficiency present and who is it seen in (it's a rare deficiency)?
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.
193
What are the first set of LNs that the superficial lateral lymph tract drain to in the leg? How about the medial tract?
Lateral tract --> popliteal nodes first and then the deep inguinal nodes.
Medial tract --> straight to the inguinal LNs.
194
What is the characteristic presentation of Wiskott-Aldrich syndrome?
Recurrent pyogenic infections in the context of low serum IgM levels, a pruritic rash, and thrombocytopenia are characteristic of Wiskott-Aldrich syndrome.
195
What is the calculation for loading dose (LD)?
LD = (desired plasma concentration) × (volume of distribution / bioavailability)
196
What are some signs of kernicterus in a baby?
Neurological sxs like hypotonia, poor reflexes and lethargy.
197
What binds unconjugated bilirubin in the blood?
Albumin
198
What is the name of the rash that accompanies fifth disease? What is the infectious agent?
Erythema infectiosum (the one with the slapped cheek appearance). Caused by parvovirus B19.
199
In addition to appearing as spherules with endospores, what is another way that coccidiodes can appear?
Barrel-shaped arthroconidia and 90-degree branching pattern
200
What is the issue/metabolism inability of Hunter and Hurler syndrome?
An inability to breakdown glycosoaminoglycans.
201
What causes Niemann-Pick disease? What is the presentation of type A disease?
An inherited deficiency of sphingomyelinase. Type A presents in infancy with progressive neurologic deterioration and hepatosplenomegaly.
202
What is the function of IL-8?
Neutrophil chemotaxis and activation. It is secreted by macrophages and T cells.
203
What sort of congenital anomaly is holoprosencephaly an example of?
Developmental Field Defect
204
What is responsible for the green color of pus and sputum from pneumonia?
Myeloperoxidase from neutrophils.
205
In general, what do most states require (or not require) in terms of parental notification or consent for abortion?
2/3 of states require consent while the other 1/3 requires notification.
206
Which pituitary cells can be classified as acidophils and which can be classified as basophils?
Acidophils --> GH and PRL secreting cells
Basophils --> FSH, LH, TSH and ACTH secreting cells
207
What is the pathophysiology of Hartnup disease? As such, how may it present?
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.
208
What tumor is associated w/ "jelly belly" (an abdomen full of mucus)?
Pseudomyxoma peritonei
209
In male embryogenesis, which cell secretes anti-mullerian factor?
Sertoli cell
210
Which cranial nerve innervates the muscles of mastication?
CN V3
211
For what pathogen do you use a calcium-alginate swab to get a culture from the pharynx?
Pertussis as you can't swab it well w/ a cotton swab.
212
Where do sperm acquire motility and what sort of epithelium is this tissue lined with?
Sperm acquire motility in the epididymis, which is lined with a layer of pseudostratified columnar epithelium with stereocilia.
213
What does a muscle bx of dermatomyositis show?
Infiltration of CD4+ T lymphocytes in the perimysium of muscle tissue.
214
What does a muscle bx of polymyositis show?
Transfascicular and intracellular CD8+ mediated inflammation.
215
What is the best medication to use to treat hyperthyroidism during pregnancy?
Propylthiouracil (PTU) is preferred during the first trimester of pregnancy b/c methimizole use during this time is associated w/ congenital malformations.
216
Of placenta previa and placenta abrupto, which has painful bleeding?
Abrupto. Previa it is painless bleeding.
217
What are the 10 essential amino acids?
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.
218
How would you describe the C2 dermatome?
It is like the posterior half of a skull cap. It's basically the top back of the head.
219
How does inspiration affect blood flow to the heart?
Inspiration increases blood flow to the right heart.
220
How does squatting affect blood flow?
It increases preload and afterload.
221
True or false, IL-6 is associated w/ increasing production of acute phase reactants?
True!
222
Name 4 muscles that the radial nerve innervates which are affected in a "wrist drop" injury?
The radial nerve innervates the Brachioradialis, Extensors of the wrist and fingers, Supinator, and Triceps ("radial nerve innervates the BEST").
223
How does the IVC pass through the diaphragm?
It passes through the central tendon of the diaphragm.
224
How does the aorta pass through the diaphragm and into the abdominal cavity?
It enters by traversing under the median arcuate ligament.
225
What travels with the vagus nerve will passing through the diaphragm?
The esophagus
226
What is the secondary messenger that increases when alpha 1 adrenergic receptors are stimulated?
IP3 increases
227
What is the difference between lead time bias and length time bias?
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.
228
The finding of pancreatic acini in a Meckel diverticulum is an example of _____?
Ectopy, which is the microscopic finding of functionally normal cells/tissue in an abnormal location due to embryological maldevelopment.
229
The ______ is the region of the LN populated mainly by T lymphocytes and dendritic cells.
paracortex
230
What do ADH, ACTH, epinephrine and glucagon have in common?
They all work by binding to G protein coupled receptors.
231
What sort of amino acids bind to Zn ions in Zn finger motifs
Cysteine and sometimes histadine
232
What is the enzyme that catalyzes the conversion of angiotensin I to angiotensin II and where is primarily found?
Angiotensin converting enzyme. Founds primarily w/in small pulmonary vessels and endothelial bound angiotensin converting enzyme.
233
What does renin do in terms of angiotensin?
It converts angiotensinogen into angiotensin I.
234
What organ produces angiotensinogen?
The liver
235
Name 2 actions of angiotensin II
1 = potent vasoconstrictor which raises SVR and thus BP and afterload.
2 = stimulates the adrenal gland to make aldosterone.
236
```
In terms of cardiac catheterization, what is normal pressure for the...
Right atrium?
Right ventricle?
Pulmonary artery?
PCWP (aka L atrium)?
```
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).
237
Where are the renin secreting juxtaglomerular cells located?
In the tunica media of the afferent arterioles of the kidney.
238
Where it the macula densa located and what is its function?
Located in the distal convoluted tubule and acts as a Na+ sensor.
239
What sort of sensation are Meissner corpuscles responsible for?
Light discriminatory touch
240
What sorts of sensation are Paciniain corpuscles responsible for?
These receptors are mainly involved in perception of pressure, coarse touch, high-frequency vibration, and tension. They are commonly damaged in diabetic neuropathy.
241
Through what vessels do the ulnar and radial arteries usually anastamose?
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.
242
What is the function of infraspinatus?
Lateral rotation of the arm.
243
What is the function of supraspinatus?
It abducts the arm initially prior to assistance from the deltoid muscle.
244
What is the function of subscapularis?
Adducts and medially rotates the arm
245
Which nerves innervate the psoas and iliacus muscles?
The psoas muscle is innervated by the lumbar plexus, and the iliacus muscle is innervated by the femoral nerve.
246
The inferior gluteal nerve innervates the?
Gluteus maximus muscle
247
The superior gluteal nerve innervates the?
Gluteus medius and minimus muscles
248
What is the most common rotator cuff injury?
Injury to the supraspinatus tendon
249
Damage to what nerve is suggested by weakness in the following actions:
- Wrist extension?
- Wrist flexion?
- Pronation of the forearm?
Wrist extension --> radial nerve injury
Wrist flexion --> ulnar and/or median nerve injury
Pronation --> median nerve injury
250
What does the infundibulopelvic ligament (aka the suspensory ligament) connect and what does it contain?
Connects the ovaries to the lateral pelvic wall and contains the ovarian vessels.
251
What causes intestinal atresia of the midgut (jejunum, ileum and proximal colon)?
Vascular occlusion in utero
252
What are the findings of midgut intestinal atresia?
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.
253
Trachea-esophageal fistula is an embryonic failure of _____?
failure of partitioning.
254
What is the most common genetic defect causing homocysteinuria?
Autosomal recessive mutation that causes cystathione synthase deficiency.
255
Why is it beneficial to give a patient who lacks IL-12 receptors INF-gamma?
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.
256
What it the chemical that induces helper T cells to become the TH2 subtype?
IL-4
257
Describe differences in terms of immune function between TH1 and TH2 cells?
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.
258
What are the two types of sweat glands, what is their stimulus and where are they located?
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.
259
What is the pathological embryological failure that occurs in diaphragmatic hernia?
Failure of the pleuroperitoneal canal to close completely,
260
Which side of the ankle is the deltoid ligament on?
The medial ankle
261
What ligament is most commonly injured in ankle sprains?
Anterior talofibular ligament.
262
What is the function of the cricothyroid muscle?
This muscle serves to increase pitch by tilting the anterior part of the thyroid cartilage forward and stretching the vocal folds.
263
What is the muscle that is torn when there is a perineal tear during child delivery that produces fecal incontinence post-birth?
The anal sphincter
264
What is the chemotherapeutic regimen used to treat Hodgkin lymphoma?
ABVD regimen --> adriamycin (doxorubicin), bleomycin, vinblastine, and dacarbazine.
265
Why is sodium thiosulfate administered alongside sodium nitroprusside used in management of malignant hypertension?
Because metabolism of nitroprusside can lead to cyanide formation and this helps prevent that.
266
what embryonic layer do microglia come from?
Mesoderm
267
Anti-smith and anti-dsDNA antibodies are specific for what condition?
SLE
268
At what point in salicylate overdose does metabolic acidosis occur? What happens before this?
About 12 hours after ingestion. Before that the drug induces a respiratory alkalosis.
269
What does the the CAAT and TATA box both do? Where in the gene are they located?
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.
270
Describe an ecological study?
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.
271
What are the changes that account for the unchanged TLC, decreased FVC and increased RV on LFTs in older people?
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.
272
What does the metanephric mesoderm (aka the metanephric blastema) give rise to?
Glomeruli, Bowman's capsule, proximal tubules, loop of henle and distal convuluted tubules.
273
What is the maintenence dose equation?
MD/Tau (dosing interval) = Cpss x CL
274
What is the loading dose equation?
LD = Vd x Cp
275
Where are B1 receptors found?
Cardiac tissue and renal juxtaglomerular cells
276
What is the physiology w/ which capsaicin treats pain in stuff like postherpetic neuralgia?
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.
277
Where do endorphins and dynorphins act in the opioid system to cause pain relief?
On the mu and kappa opioid receptors respectively.
278
How does a musculocutaneous nerve injury present?
Loss of forearm flexion, supination, and loss of sensation to the laternal forearm.
279
On what chromosome is genetic defect in NF-2?
NF-2 = chromosome 22. NF-1 is chromosome 17.
280
What does the obturator nerve innervate?
The adductor muscles in the median compartment of the thigh.
281
Through what space does the facial nerve exit the skull?
Through the stylomastoid foramen.
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)?
Location = space of Disse
Vitamin = Vitamin A.
283
Describe the borders of the femoral triangle
It is a subfascial space bounded superiorly by the inguinal ligament, medially by the adductor longus muscle, and laterally by the sartorius muscle.
284
What produces ADH?
The supraoptic nucleus of the hypothalamus.
285
What is the timeframe of onset for hyperacute, acute and chronic transplant rejection? And the mechanism?
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.
286
What is the clinical presentation of patients with essential thrombocythemia?
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).
287
Where is type II collagen found?
Cartilage, vitreous body, nucleus propulsus.
288
What protein is overexpressed in Burkitt lymphoma? Follicular?
Burkitt --> C-Myc
| Follicular --> BCL-2
289
What is deficient in Hunter syndrome and what does this cause accumulation of?
It is caused by a deficiency in iduronate sulfatase, leading to accumulation of the mucopolysaccharides dermatan and heparan sulfate in affected tissues.
290
What sort of pathogen is Haemophilus ducreyi? How does it present?
Gram-negative coccobacillus. Presents as a painful ulcer with an erythematous base that bleeds easily when manipulated. Unilateral inguinal lymphadenopathy may be seen.
291
How many days after fertilization does the oocyte divide in order to get mo/di monozygotic twins?
Between 4-8 days after fertilization.
292
What is rubeola another word for?
Measles
293
What pattern of liver injury is seen in acetominophen overdose?
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..
294
What causes zone I (periportal) liver damage?
Affected first by viral hepatitis. Also affected by toxins like cocaine.
295
What causes zone II (intermmediate zone) liver damage?
Yellow fever.
296
Which class of antibiotics disrupts protein synthesis by blocking translocation?
The macrolides (they bind to the 23s rRNA on the 50S ribosomal subunit).
297
What is the tx for De Quervian (aka subacute granulomatous thyroiditis)?
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.
298
True or false, a living will supersedes a durable power of attorney for medical decisions?
FALSE! It is in fact the opposite and a durable power of attorney supersedes even a living will.
299
What is the pathophysiology of osteopetrosis?
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.
300
What is alkaptonuria?
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.
301
What are the derivatives of the ventral pancreatic bud?
The proximal portion of the main pancreatic duct and the uncinate process (a small portion of the pancreatic head).
302
What are the derivatives of the dorsal pancreatic bud?
Pancreatic tail, body, most of the head, and the small accessory pancreatic duct.
303
What is the case-fatality rate?
Proportion of reported cases of a condition or disease that are fatal within the population affected by the condition or disease over time.
304
What are the metabolic effects of thiazides?
Raise LDL cholesterol and triglycerides. They also decrease the secretion of insulin and reduce the uptake of glucose in peripheral tissues.
305
What is the difference between factitious disorder and malingering?
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).
306
Why can admin of mu opioid potentially lead to biliary colic?
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.
307
What is the action of opioids at the pre-synaptic neuron by binding to mu receptors? How about at the post-synaptic neuron?
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.
308
Why are the testes small in Klinefelter syndrome?
There is progressive destruction and hyalinization of the seminephrous tubules.
309
What does cryoprecipitate contain?
Only cold soluble proteins which are factor VIII, fibrinogen, VW factor and vitronectin
310
What is the defect in familial hypocalciuric hypercalcemia (FHH)? Name the class of the specific protein that is mutated.
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.
311
Name 3 hormones that work through the JAK-STAT pathway.
GH, PRL and erythropoietin
312
What does deficiency in aldolase B cause? What accumulates?
Heriditary fructose intolerance. Fructose 1-Phosphate accumulates.
313
What is prosopagnosia? Infarct to what area of the brain causes it?
Inability to recognize faces. It is most often caused by a lesion in the right inferior temporal lobe, specifically the right fusiform gyrus.
314
What are the typical cancers seen in Li-Fraumeni syndrome?
Typical cancers include osteosarcomas, soft tissue sarcomas, early-onset breast cancers, adrenocortical tumors, and leukemias
315
What does cystathione deficiency cause?
Homocystinuria
316
Where do the initial steps of the urea cycle, converting NH3 to urea, occur?
In the mitochondria of hepatocytes.
317
What are the first two steps of the urea cycle?
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).
318
What does Western blot detect? How about Northern blot? Southern blot?
- 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.
319
Decreased maternal serum AFP and increased fetal nuchal translucency on US suggest what?
Trisomy 21
320
Why is memantine a drug that can be used in the treatment of Alzheimer's?
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.
321
What encapsulates the median nerve in the "carpal tunnel?"
The transverse carpal ligament (flexor retinaculum) and the carpal bones more deeply.
322
What conditions is carpal tunnel syndrome associated with?
Pregnancy, hypothyroidism, DM, rheumatoid arthritis and long hx of hemodialysis. These things reduce carpal tunnel space (through deposition of stuff).
323
Why is H2PO4- increased in the urine in DKA?
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.
324
What are the two major buffers of acid in urine?
NH3 and H2PO4-
325
Why does neutrophil count increase in the differential of WBC after admin of corticosteroids?
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.
326
Where is IGF-1 made?
In the liver.
327
What are the positive and negative regulators of phosphofructokinase in glycolysis?
Positive --> AMP, fructose 2-6 bisphosphate
Negative --> citrate, ATP
328
What type of GPCR are histamine1 and vasopressin1 receptors?
Gq
329
The vascular variant of Ethers-Danlos is associated with a defect in what?
Type III Procollagen
330
What is mutated in epidermolysis bullosa
Keratin 5 or keratin 14, the two major keratins in basal epithelial cells.
331
What are the essential fatty acids?
linoleic and linolenic acid.
332
What enzyme is deficient in benign fructosuria and why is it benign?
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.
333
ST elevation in what ECG leads indicate acute occlusion of the right coronary artery?
II, III and aVF
334
In addition to HIV tx what is an immune modulating medication that can be used for Kaposi's sarcoma?
a-interferon (aka a2b interferon). It has anti-tumor properties by activating various aspects of the immune system.
335
What is the initial testing for HIV?
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
336
When clamping the uterine arteries during a hysterectomy, what structure must you take care not to harm due to its close proximity?
The ureters.
337
True or false, Gonorrhea is a reportable infection in all 50 states?
True!
338
Which LNs do the ovaries drain to first?
The para-aortic LNs
339
How long must chronic depressed mood be present in order to make a dx of persistent depressive disorder (dysthymia)?
At least 2 years.
340
What sort of antibodies does vaccination against N. meningitidis provide?
Capsular polysaccharide antibodies. I think the exception is the vaccine against the B subtype which has only recently been introduced.
341
What is the difference between unfractionated heparin and LMWH like enoxaparin?
Both can inactivate factor Xa whereas only UFH inactivates thrombin too.
342
What type of drug is fondaparinux?
It is a direct factor Xa inhibitor.
343
Why can mycoplasma pneumoniae cause anemia?
Because you can get IgM antibodies that cross react w/ erythrocyte cell membranes. These are called cold agglutinins and can cause a hemolytic anemia.
344
What causes release of BNP? What does it do?
BNP is released by the ventricles in response to stretch (volume overload). It (along w/ ANP) causes decreased BP, diuresis/natriuresis and vasodilation.
345
What does rasburicase do and when would you administer it?
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.
346
What is the difference between an UMN lesion of CN7 and a LMN lesion of CN7?
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.
347
Name what the following are markers for:
CD27?
CD56?
CD34?
CD27 --> plasma cells
CD56 --> NK cells
CD34 --> fibrocytes
348
What is the prominent mediator of acute rejection of trasnplant organs?
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.
349
How does hereditary orotic aciduria present? What enzyme deficiencies cause it?
Symptoms include poor growth, megaloblastic anemia, and orate crystals in urine.
Deficiency of Orotate phosphoribosyltransferase or orotidine 5′-monophosphate decarboxylase cause it.
350
How does galactokinase deficiency present?
With galactosuria, galactosemia and can get infantile cataracts from accumulation of galactitol.
351
What is the one K+ sparing diuretic that is not in the sulfa category?
Ethcrynic acid
352
Where are the inhibitory neurons lost in achalasia (like what tissue layer)?
Loss of inhibitory neurons at he Auerbach plexus aka the myenteric plexus.
353
True or false, you can microalbuminuria (30-300mg/day of loss) on a urine dipstick?
False! Microalbuminuria may indicate nephropathy in DM pts.
354
How does DM nephropathy present on microscopy?
Glomerular basement membrane thickening and increased mesangial matrix deposition.
355
What are the inferior pancreaticoduodenal arteries a branch of?
The superior mesenteric artery.
356
Erb's palsy results from damage to which brachial plexus trunk? What are the rami that feed into it?
Damage to the upper trunk which is fed by C5-C6 ventral rami
357
Infection w/ ______ causes itching and serpiginous burrows in the webspace of hands and feet.
Scabies
358
Why do the lesions of psoriasis become less severe during summer?
Because exposure to UV light is therapeutic for psoriasis.
359
What does it mean to see parakeratosis?
It means that on histo of tissue including skin, there are nuclei still in the stratum corneum, which is abnormal.
360
What pathogen is classically described as having a spaghetti and meatballs appearance on KOH prep? What does it cause?
Malassezia furfur causing tenea versicolor (patients have areas of hypo or hyperpigmentation).
361
What is permethrin cream used to treat?
Scabies
362
What is a keratoacanthoma?
A variant of squamous cell carcinoma that grows rapidly over the matter of weeks. It may regress spontaneously.
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.
Rosecea = the rash.
First line tx = tetracyclines or topical metronidazole.
364
Distinguish seborrheic dermatitis from scalp psoriasis.
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).
365
Atopic dermatitis is another name for _____? Where is the rash commonly seen?
Eczema. Rash is typically seen on flexural surfaces like the antecubital fossa. Can be seen on babies' faces during infancy.
366
How does the rash of livedo reticularis present?
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.
367
How does the rash of necrobiosis lipoidica present and who does it commonly affect?
Presentation: reddish-brown plaques that progressively become more yellow, shiny and atrophic in appearance.
Typically affects the shins of insulin dependent diabetics.
368
How does parvovirus B19 present in adults?
A lacy erythematous rash with rheumatoid-arthritis like arthropathy. The rash is morbilliform. It can cause hydrops fetalis when it occurs in pregnant women.
369
What is pulsus paradoxus?
A drop is systolic BP that is greater than 10 mmHg on inspiration.
370
What is the primary treatment for an acute COPD exacerbation?
Inhaled beta-agonists.
371
What are the most frequent causes of pulsus paradoxus in the absence of pericardial disease?
COPD and asthma.
372
Opiate action at which receptor causes respiratory and cardiac depression? How about reduced GI motility? How about miosis?
Mu --> respiratory and cardiac depression, reduced GI motility
Kappa --> miosis
373
What is the name of the drug that inhibits cholesterol absorption from the GI tract?
Ezetimibe
374
How do fibrates work?
They activate the peroxisomal proliferator-activated receptor alpha, which is a transcription factor that increases lipoprotein lipase activity.
375
In a positively skewed distribution, the mean is generally ______ than the median?
mean is generally higher than the median.
376
What is the most common genetic cause of idiopathic pulmonary hypertension? What is medical treatment while awaiting transplant?
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.
377
In order to undergo reassortment, what sort of viral genome must you have?
A segmented genome.
378
What are the major side effects associated with CCBs like amlodipine?
Headache, dizziness, flushing and peripheral edema.
379
Wide, fixed splitting of S2 that does NOT vary with respiration is associated with what?
Atrial septal defect.
380
How does hypercalcemia present?
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).
381
Why can patients w/ granulomatous disease and sarcoidosis have hypercalcemia?
Because activated macrophages in these diseases express 1-a-hydroxylase, this leads to excess 1,25-dihydroxyvitamin D, which can lead to hypercalcemia.
382
What is seen histopathologically in HIV associated dementia?
Microglial nodules. These form from activated macrophages and microglial cells.
383
What does IgM in an infant's serum suggest?
Some sort of intrauterine infection like congenital CMV.
384
What is a craniopharyngioma derived from?
It is a remnant of Rathke's pouch, which is a diverticulum of the roof of the embryonic oral cavity (oral ectoderm).
385
What does the diencephalon become?
The thalamus, hypothalamus and third ventricle.
386
What is the precursor lesion to squamous cell skin cancer? How is it described?
Actinic keratosis = precursor lesion. It is described as a scaly plaque.
387
What is the male embryological equivalent (i.e. develops from the same place) of the labia majora?
The scrotum. These things develop from the labialscrotal swelling.
388
What does the urogenital folds become in men and women respectively?
The ventral shaft of the penis (penile urethra) and the labia minoria respectively.
389
What does the genital tubercle become in men and women respectively?
Men: glans penis and corpus cavernosum and spongiosum.
Women: glans clitoris and vestibular bulbs.
390
How is diagnosis of ankylosing spondylitis made?
Through imaging like X-ray of the sacroiliac joints. These pts have "bamboo spine." There are no serum markers for AS that allow dx.
391
Anti-nuclear antibody testing is done for what disease?
SLE
392
Which classes of heart-block are generally treated with a pacemaker.
Type 3 and mobitz type 2 (where there are dropped beats that are not preceded by a lengthening of the PR interval).
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?
The left atrium.
394
What is the most common porphyria and how does it present?
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).
395
What enzyme is deficient in porphyria cutanea tarda and what substrate accumulates?
Enzyme = uroporphyrinogen decarboxylase.
Substrate that accumulates = uroporphyrin (causing tea-colored urine).
396
How does riboflavin (B2) deficiency present?
Cheilosis (inflammation of lips, scaling and fissures out mouth corner), and corneal vascularization.
397
In internuclear ophthalmoplegia, the MLF lesion is ipsalateral or contralateral of the affected eye?
Ipsalateral. (I am pretty sure, check p.490 of first aid to double check).
398
What amount of functional LDL receptors are present in familial hypercholesterolemia where pts have tendon xanthomas?
None (per firstaid p.71). They are completely absent or defective.
399
What is the personality disorder where the person is voluntarily withdrawn, has limited emotional expression and is content with social isolation?
Schizoid personality disorder
400
What is the personality disorder where the person has an eccentric appearance, has odd beliefs or magical thinking, and interpersonal awkwardness?
Schizotypal personality disorder
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)?
In primary renin is decreased whereas in secondary renin is increased.
402
In the sensory and motor homonculi, what does the lateral part correspond to? How about the part closest to midline?
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.
403
What skin lesion is described as firm, smooth umbilicated papules? What causes it?
Molloscum contagiosum. Caused by poxvirus.
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?
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.
405
What is sulfasalazine and what is it used to treat?
It is a combo of the abx sulfapyridine and the anti-inflammatory 5-aminosalicylic acid. It is used to treat Crohns and UC.
406
How does Churg-Strauss present?
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.
407
What is the triad seen in granulomatosis w/ polyangiitis (Wegener's)?
Focal necrotizing vasculitis, necrotizing granulomas in the lung and upper airway, necrotizing glomerulonephritis.
408
Describe the upper respiratory sxs that can be seen with granulomatosis w/ polyangiitis?
perforation of nasal septum, chronic sinusitus, otitis media, mastoiditis.
409
In what population is sarcoidosis most common?
Africa-American females.
410
What are some things that are associated w/ sarcoidosis?
Restrictive lung disease (interstitial fibrosis), erythema nodosum, lupus pernio, Bells palsy, uveitis, hypercalcemia.
411
On a cross section of the cavernous sinus, what is the CN that is running in the interior closest to the internal carotid?
CN6 (abducens)
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.
Top to bottom: CN3, CN4, CN5 ophthalmic division, CN5 maxillary division.
413
How does chronic abuse of inhaled glue present?
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).
414
What characteristic of amyloid gives its characteristic staining appearance?
Its Beta-pleated sheet structure.
415
How does cyclosporin work?
It blocks T cell activation by preventing IL-2 transcription.
416
What makes up the striatum in the brain? How about the lentiform nucleus?
Striatum = caudate + putamen
| Lentiform nucleus = putamen + globus pallidus.
417
Why can Turner syndrome pts present w/ amenorrhea in adolescence?
Low estrogen levels due to non-functional ovaries (histo reveals streaks of tissue devoid of primordial follicles).
418
What congenital cardiac defect is associated w/ "an egg on a string" appearance on CXR?
Transposition of the great vessels
419
What is the most common cause of death in infants w/ congenital diaphragmatic hernia?
Pulmonary hypoplasia.
420
Embryologically, what muscle is the source of the cremaster muscle?
The internal oblique muscle
421
What nerve innervates the cremaster muscle?
Genitofemoral nerve
422
Deep to Superficial, what are the layers of the spermatic cord and what are they derived from embryologically?
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.
423
What layer of the skin are melanocytes located?
Stratum basalis.
424
What are the layers of skin from superficial to deep?
Corneum, lucidum, granulosum, spinosum and basale.
425
Which nerve and from what spinal levels stimulate sperm to move into the urethra (aka emission)(?
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.
426
Which nerve is responsible for ejaculation?
The pudendal nerve - somatic and visceral fibers
427
What does musculocutaneous nerve injury present as?
Inability to flex and supinate the forearm. Also, loss of sensation over the lateral forearm.
428
What does the Edinger-Westphal nucleus contain and what do these fibers do?
Contains preganglionic parasympathetic neurons that travel w/ CNIII and help w/ pupillary constriction and accommodation.
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.
ilioinguinal nerve
430
Forceful, postprandial, nonbilious vomiting in the first 2 months of life suggests ...?
Pyloric stenosis
431
Oocytes are arrested in ______ until ovulation and at ovulation they progress w/ meiosis until arresting in _____ until fertilization?
Prophase I, metaphase II
432
In regards to enzyme kinetics, a dissociation constant is equal to what?
The concentration of substrate at which the binding site on the enzyme or protein is 50% bound by substrate.
433
What causes acute serum sickness and how does it present?
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.
434
Connexins help make up what structure?
Gap junctions
435
Claudins and accludins help make up what structure?
Tight junctions
436
What happens to stop the apnea in OSA?
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.
437
How do you calculate standard error?
SE = SD/ square root of n
438
How do you calculate the confindence interval of the mean?
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.
439
Through what area does herniation occur in indirect inguinal hernia and what embryologically predisposes to this?
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.
440
What structures are derived from the mesonephric duct?
The vas deferens, along with the epididymis, seminal vesicles, and ejaculatory duct, is derived from the mesonephric duct.
441
Valgus stress test of the knee tests what ligament?
MCL
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?
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.
443
Is it endometrial hyperplasia or adenomyosis that presents with a globally enlarged uterus?
Adenomyosis. Conversely, endometrial hyperplasia generally presents w/ post-menopausal bleeding and is known for increased risk of endometrial carcinoma.
444
What interaction causes Hgb sickling in sickle cell disease?
The mutations creates a hydrophobic pocket on the B globin surface that allows for hydrophobic interactions between globin molecules. This interaction leads to sickling.
445
What promotes red cell sickling in sickle cell anemia?
Low oxygen, increased acidity and dehydration.
446
What are the three phases (in order) that occur in Paget's disease of the bone?
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.
447
What neural structure lies within the fascia surrounding the prostate? What does this structure do?
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.
448
Branches of the pudendal nerve innervate which sphincters?
The external urethral sphincter and the anal sphincters.
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.
Langerhans cells.
450
Describe the process of base excision repair included the order of the enzymes used
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.
