Q Banks: Week of 03/06/17 Flashcards
(155 cards)
1
Q
What cardiac manifestations does carcinoid syndrome present with?
A
Valvular calcifications (most often right-sided)
2
Q
Don’t forget that ________________ should not be taken with lithium.
A
NSAIDs, thiazide diuretics, or ACE inhibitors
All of these drugs lead to increased GFR by mild volume depletion. As such, they increase the amount of electrolytes reabsorbed by the nephron, which can lead to excessive lithium levels. Lithium toxicity manifests as nausea, ataxia, and tremors.
(Think of the thiazide pool with the “low clearance” ski lift wires in the Sketchy scene.)
3
Q
How might you diagnose nocturnal dyspnea in a patient with normal spirometry values?
A
Methacholine challenge
Asthma can present as episodic cough with nocturnal dyspnea. If the patient has normal spirometry values in the clinic, then methacholine can uncover asthma.
4
Q
Describe erythema multiforme.
A
EM is an immune response to an infection that presents about 1 to 2 weeks after the initial infection. The rash presents with circular target macules –not vesicles –often on the extremities. It is classically associated with HSV (remember the red postage stamps on Hermes’ arm) and Mycoplasma.
Note: disseminated HSV, such as in an immunocompromised patient, will present with vesicular rash, not macular target lesions.
5
Q
Parvovirus can present with ______________ in sickle cell patients.
A
aplastic anemia (like the sickle on the USSR plane bombing the bone in the Sketchy scene)
6
Q
Atypical lymphocytes (seen in EBV infection) have CD_.
A
8
Think of the cross on the knight’s tunic in the Sketchy scene.
7
Q
IgG and _____ can opsonize bacteria.
A
C3b
Also, mannose-binding lectin and CRP
8
Q
How does Clonorchis sinensis cause pigment gallstones?
A
C. sinensis damages the common bile duct. That damage causes hepatocytes to release beta-glucuronidase into the bile duct. Beta-glucuronidase deconjugates bilirubin, causing it to be less soluble and thus precipitate.
9
Q
Estrogen increases hepatic uptake of ____________.
A
cholesterol (this is why estrogen increases the risk of CHOLESTEROL gallstones)
10
Q
Why does homocysteine increase risk of thrombotic event?
A
It’s thought to be due to endothelial damage.
11
Q
A patient has high levels of homocysteine. How can you differentiate which of the two most common genetic conditions he might have?
A
- Cystathionine beta-synthase deficiency is an AR defect in the enzyme that converts homocysteine to cystathionine. (This reaction uses B6.) This disorder will present with a Marfanoid body habitus and intellectual disability.
- Methyltetrahydrofolate reductase (MTHFR) deficiency presents with decreased ability to methylate homocysteine. Methylation is required to convert homocysteine to methionine. (This reaction uses B12.) This disorder can often be asymptomatic until someone has a clot.
12
Q
What does S-adenosyl methionine become after it has methylated something (such as DNA)?
A
S-adenosyl homocysteine
This becomes homocysteine after releasing its S-adenosyl group.
13
Q
True or false: acute rheumatic fever only results from untreated bullous impetigo with group A Strep.
A
False. ARF is only caused by pharyngitis –not impetigo.
14
Q
What is the classic feature of agoraphobia?
A
Agoraphobia presents with fear in public situations because escape might be impossible or help will not be there if the person has a panic attack or are incapacitated.
15
Q
Social anxiety disorder presents with what symptoms?
A
- Avoidance of social gatherings due to fear of scrutiny or embarrassment
- Impairment of life functions (missing school or work due to anxiety)
- Avoidance of eye contact
- Comfort in social situations when the individual is not the center of attention (this is in contrast to agoraphobics who often fear being in social situations even when they are not the focus of attention)
16
Q
How is histrionic personality disorder different from borderline personality disorder?
A
Both present with attention-seeking behavior, but BPD presents with self-destructive actions such as promiscuity or interpersonal fights.
17
Q
The protein that inhibits ferroportin is released from _____________ cells.
A
hepatic parenchymal
this being HEPcidin
18
Q
The ____________ thalamic nucleus receives sensory and pain info from the contralateral body (excluding face and head).
A
ventral posterior lateral
19
Q
The ___________ thalamic nucleus receives sensory and pain information from the contralateral face.
A
ventral posterior medial
20
Q
Explain the process that leads to lacunae in the basal ganglia.
A
Lipohyalinosis occurs when plasma proteins leak into the artery wall and occlude the lumen. Thus, infarcts occur distal to the narrowing.
21
Q
In isolated diastolic heart failure, the end-diastolic pressure of the left ventricle is _______________.
A
increased
Recall that isolated systolic heart failure occurs when the left ventricle becomes stiff. As such, the left atrium has to work a lot harder to push blood in.
22
Q
The scrotal skin drains to which lymph nodes?
A
The superficial inguinal
23
Q
The __________________ drain to the deep inguinal lymph nodes.
A
glans penis and posterior calf
24
Q
Neural tube defects present with what two markers in the amniotic fluid?
A
- Alpha-fetoprotein
* Acetylcholinesterase
25
What three cytokines are crucial in the pathogenesis of sepsis?
TNF-alpha, IL-1, and IL-6
26
Leukotriene B4 leads to _____________.
neutrophil chemotaxis
27
The vast majority of nose bleeds occur on the ___________________.
nasal septum
Specifically, the area known as Kiesselbach's plexus is the confluence of three arteries and is a common site for nose bleeds.
28
If a patient has a UTI in the hospital and the micro report notes Gram-positive cocci in chains, what organism should you treat for?
Enterococcus
Note: this is considered a gamma-hemolytic organism.
29
What is the power of a study?
Power = 1 – Beta
Beta is the probability of making a type II error (saying that there is no difference when there actually is one). As such, beta decreases with increased sample size and therefore power also increases with increased sample size.
30
What are the two most serious side effects from aminoglycoside usage?
* Ototoxicity (remember the samurai in the Sketchy scene holding his ears after the gong was struck)
* Acute tubular necrosis (the rain gutter in the same Sketchy with the clogged brown mud that resembles brown casts in tubules)
31
Explain the cycle of tetra- and dihydrofolate.
* Methyltetrahydrofolate donates a methyl group to dUMP to make it dTMP (catalyzed by thymidylate synthase)
* In the process of methyl transfer, tetrahydrofolate becomes dihydrofolate
* Dihydrofolate reductase adds the two hydroxyl groups lost in the methylation process (this is what methotrexate inhibits)
* Tetrahydrofolate gets remethylated
32
What kind of receptor is the insulin-inducible glucose channel?
Carrier-mediated glucose transport
33
True or false: CYP450 enzymes are only found in the liver.
False. They are also extensively found in the gut wall.
34
Which immunosuppressant can cause nephrotoxicity?
Cyclosporine (and any other calcineurin inhibitor such as tacrolimus)
Note: the mechanism by which this occurs is through vasoconstriction of the renal arterioles.
35
What is pharmacodynamic potentiation?
When two drugs have a total effect greater than the sum of the two separate effects
36
```
In terms of microbial genetic differences, explain each of the following:
• Interference
• Phenotypic mixing
• Recombination
• Transformation
• Reassortment
```
* Interference: when one virus inhibits the replication of another virus
* Phenotypic mixing: when the genome of one virus can acquire the envelope or capsid of another virus WITHOUT THE GENOME BEING CHANGED
* Recombination: two viral genomes being mixed with resultant phenotypic fusions
* Transformation: when a bacteria absorbs new DNA from the environment
* Reassortment: when a segmented virus rearranges its segments with another strain
37
What conditions can increase the risk of gout?
* Myeloproliferative disorders like polycythemia vera
* Tumor lysis syndrome
* HGPRT deficiency
All of these lead to the accumulation of purines.
38
What bone degradation pattern is typical of hyperparathyroidism?
Subperiosteal thinning with cystic degradation
This is because the macrophages activated by PTH are primarily on the periphery of the bone.
39
Describe Paget's disease of the bone.
* Disorganized lamellar bone pattern (like the disorganized exhibit in the Sketchy scene)
* Normal Ca
* Normal Phos
* Elevated alkaline phosphatase
40
What bone pattern is characteristic of osteoporosis?
Trabecular thinning with fewer interconnections
41
Persistence of the bone spongiosa is a sign of _____________.
osteopetrosis
42
Macrophages and neutrophils both secrete elastase and matrix metalloproteases. Where are the anti-proteases found?
In the serum and tissue
43
What organisms causes the most cases of meningitis in those in their 40s?
S. pneumoniae
44
Why do propofol and thiopental cause quick onset and quick offset anesthesia?
Both thiopental and propofol are highly lipophilic agents. They distribute to the brain initially because the brain has high blood flow and these agents are administered intravenously. They saturate the fatty tissue of the brain initially, but after some time they distribute to the blood and accumulate in organs with less blood flow.
45
Explain the phenomenon of phenotypic mixing.
Phenotypic mixing is the process in which two viruses infect one cell and then the capsid of one virus encapsulates the genome of the other. Thus, the hybrid would be able to infect the cells that are specific to the capsid, but when new virions are made the genome will recreate the original capsid.
46
What cellular interactions cause toxic shock syndrome?
Bacteria release a toxin that binds MHC II to CD4. Thus, to have toxic shock syndrome you need an antigen-presenting cell (macrophage, dendrite, or B cell) and a helper T cell. When this interaction occurs, T cells are continuously stimulated and release excessive amounts of IL-1 and IL-2.
47
What imbalance is the most common cause of kidney stones?
Idiopathic hypercalciuria with normocalcemia
It's thought that most kidney stones are due to idiopathic increased GI absorption of calcium, increased resorption of calcium from bone, or decreased calcium resorption from the renal tubule. However, because the Ca, vitamin D, PTH system is intact, people with these imbalances will have normal serum calcium levels.
48
True or false: all dehydrogenases in the TCA cycle utilize niacin as a cofactor.
False. Although most do – pyruvate dehydrogenase, isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, and malate dehydrogenase all do – succinate dehydrogenase doesn't.
("Succinate is the Sole dehydrogenase that doesn't need niacin.")
Note: niacin is used to make NAD, and NAD is the form used by these enzymes. Succinate dehydrogenase uses FAD.
49
Why does a high NADH:NAD+ ratio stimulate lactate production?
Glycolysis makes NADH. Lactate production converts NADH back to NAD so that glycolysis can continue to make ATP.
50
What are the two most common sites of aspiration pneumonia to develop in SUPINE individuals?
* Superior region of the lower lobe
| * Posterior region of the superior lobe
51
Why is skeletal muscle not blocked by verapamil?
In skeletal myocytes, the voltage-sensitive calcium channels are connected to ryanodine receptors. Thus, depolarization causes release of calcium from the sarcoplasmic reticulum REGARDLESS of if the channel is blocked by verapamil. In cardiac nodal cells, however, there is no physical excitation coupling to ryanodine receptors; calcium from the extracellular environment enters the cell and activates a ligand-gated ion channel on the sarcoplasmic reticulum. Thus, blocking L-type channels in cardiac cells prevents excitation.
52
Describe the phases of meiosis that the oocyte goes through (1) prior to puberty, (2) during the ovulation cycle, and (3) prior to fertilization.
(1) The oocyte gets paused at prophase I from gestation to puberty.
(2) Each monthly cycle, one oocyte matures from prophase I to metaphase II.
(3) Meiosis II is completed just prior to fertilization.
53
Why does TPN increase risk of gallstones?
Without stimulation of the intestines, less CCK is released and the gallbladder lacks motility. Similarly, in those who've had intestinal resections, there is less CCK released and gallstones may form.
54
Which kind of hernia is more common?
Indirect > direct
55
What structures make up the triangle of Hesselbach?
* Medial: rectus abdominis
• Lateral: inferior epigastric vessels
* Inferior: inguinal ligament
56
What does absence of green fluorescence on dihydrorhodamine testing indicate?
Chronic granulomatous disease
Note: this can be a little tricky because myeloperoxidase is what gives sputum its green hue, so you might think MPO is what gives neutrophils their green fluorescence in the dihydrorhodamine assay, but this is not so.
57
If someone with stable angina cannot tolerate aspirin due to bronchoconstriction, what is the next agent you should offer them?
Clopidogrel, ticagrelor, or ticlodipine (any of the ADP receptor blockers that work similarly to aspirin)
58
Cardiac output = (_________________)
__________________
Arteriovenous O2 difference
rate of O2 consumption
59
Ulnar nerve injury most often occurs at which two spots?
* Medial epicondyle of the elbow (funny bone spot)
| * Hook of hamate
60
Ulnar nerve injury presents with defective ______________.
* Sensation of the fourth and fifth digit
* Wrist adduction
* Finger abduction and adduction (lumbricals)
* Flexion of the fourth and fifth digits
61
What lab distinguishes between obstructive sleep apnea and obesity hypoventilation syndrome?
Arterial blood gas
In OHS, the extra chest weight prevents normal expansion of the chest. As such, people with OHS develop chronic respiratory acidosis.
In OSA, the chest is able to expand normally but the pharyngeal muscles weaken during sleep and lead to brief apneic spells. The ABG will be normal because when they are awake they are breathing normally.
62
Discuss the risks of aortic stenosis and aortic dissection in those with bicuspid aortic valves.
* Aortic stenosis is very common and typically presents around age 50 (10 years earlier than the average presentation in a patient without BAV).
* Aortic dissection risk is increased, but it occurs in less than 1% of the cases of bicuspid aortic valve.
63
According to UWorld, ______________ is better at preventing incorrect dosage than computer systems that flag inappropriate orders.
educating physicians against trailing zeroes
64
Congenital long QT syndrome is caused by mutations in ________________.
membrane potassium channels (Lange-Nielsen and Romano-Ward are examples of this)
65
In addition to lip and genital lesions, HSV-1 can also cause _________________.
* Encephalitis
* Hard palate lesions
* Swollen gums
66
Giant cell arteritis is caused by _______________ of the blood vessels.
medial granulomatous necrosis (hence, giant cells are found in granulomas)
67
The true vocal cords are _____________ to the false vocal cords.
medial
68
Which location in the airway can HPV infect?
The true vocal cords
| "It's TRULY a good idea to get vaccinated against HPV."
69
What does vitamin A overdose cause in pregnancy?
A phenocopy of DiGeorge!
70
Maternal diabetes, particularly if it is poorly controlled, raises risk of fetal ______________ regression syndrome.
caudal
This presents with absent lower extremity reflexes, incontinence, and anal atresia.
71
By what pathway can alanine be converted to glucose?
It gets deaminated to form pyruvate, and then pyruvate goes through the standard gluconeogenesis pathway to produce glucose.
72
What dose ethanol get converted to?
Acetyl CoA
73
How does alcohol inhibit gluconeogenesis?
Alcohol metabolism generates NADH and thus increases the NADH/NAD+ ratio. Many of the reactions in the gluconeogenesis pathway are dependent on NAD+. In particular, high NADH causes pyruvate to get converted to lacte (which makes NAD+). LIkewise, NADH inhibits the conversion of malate into oxaloacetate. Pyruvate and oxaloacetate are necessary intermediates in the gluconeogenesis pathway, so decreasing those inhibits gluconeogenesis.
74
With highly lipophilic drugs, which tissues will be perfused last?
* Skeletal muscle
* Bone
* Fat
All of these are less vascularized than the visceral organs such as the brain, liver, kidney, lungs, and heart. However, because the total volume of the muscles, fat, and bone is greater than that of the organs, lipophilic drugs will eventually be predominately found in the muscles, fat, and bone.
75
The ______________ molecule occupies the antigen-binding site in MHC prior to the antigen itself (which gets loaded in acidified vacuoles).
invariant chain
76
How does diabetes insipidus affect the ICF volume, ECF volume, and serum osmolarity?
* ICF: decreases
* ECF: decreases
* Osmolarity: increase
Because the kidneys aren't concentrating urine, fluid is lost. This leads to volume depletion. The volume lost in DI is greater than the electrolyte loss, so osmolarity increases.
77
Higher-affinity hemoglobin mutations – like Chesapeake hemoglobin – lead to what hematologic abnormality?
Erythrocytosis
78
True or false: African-American women have a higher rate of osteoporosis due to lower levels of vitamin D.
False. African-American women have the lowest rate of osteoporosis.
79
What things can precipitate acute decompensated heart failure?
* Hypertension
* MI
* Drugs (cocaine)
* Arrhythmia
* Valve disease
80
Differentiate bipolar I and II.
Both require cycling between depressive episodes and mania (I) or hypomania (II). Hypomania is like mania – presenting with decreased need for sleep and elevated mood – but it is less severe and does not have psychotic features. For instance, a hypomanic person would likely be able to show up to work and be productive while a manic person would be impaired enough to not be able to work.
81
Levetiracetam disrupts the ____________________.
fusion of vesicles containing neurotransmitters
82
Explain how hox clusters work.
Homeobox clusters (aka hox clusters) are 180 repeats of nucleotide that transcribe transcription factors that activate a suite of other genes. Development is controlled by activating certain hox genes only at certain times.
83
Inferior orbital floor fractures can disrupt the ____________ nerve.
infraorbital (a branch of the maxillary that innervates the cheek and gums)
84
Mycoplasma requires _______________ to grow.
cholesterol
85
The organism ______________ is said to have a Medusa head appearance on microscopy.
Bacillus anthracis
86
Drugs with high _________________ tend to be excreted by the liver.
lipophilicity
If a drug is lipophilic, it will likely diffuse across renal tubule membranes and not be filtered successfully. Thus, it will require hepatic elimination.
87
Drugs that are _________________ tend to have a low rate of redistribution.
hydrophilic
Hydrophilic drugs do not cross lipid membranes as easily and thus take longer to diffuse from the blood into the tissues.
88
Explain the axonal properties of length constant and time constant.
* Length constant: the distance at which the original potential dissipates to 37% of its value; myelination INCREASES the length constant and thus prevents the potential from getting too quickly attenuated
* Time constant: the amount of time it takes for a change in membrane potential to decrease to 63% of its new value; myelination DECREASES the time constant and allows for quicker transmission of signals in succession
Multiple sclerosis thus decreases length constant and increases time constant.
89
A person returns from the tropics with bone pain, fever, and petechiae. What kind of virus caused this?
The stem describes Dengue fever, caused by the Dengu Flavivirus… ssRNA, positive-sense, enveloped, non-segmented.
90
Congenital hydroceles are caused by what pathology?
Patent tunica vaginalis
The connection to the peritoneum is normally obliterated, but if it remains patent then hydroceles develop.
91
Where is LPS found in Gram-negative bacteria?
On the outer membrane
92
Degree of ________________ usually correlates with intensity of symptoms in N. meningitidis infection.
LOS concentration in serum
93
In addition to the VDRL, the ___________ test can also come back positive in those with lupus.
rapid plasma reagin (RPR)
94
Which of the common meningitis-causing organisms is resistant to cephalosporins?
Listeria
UWorld says that Listeria is resistant to cephalosporins because it has altered penicillin-binding proteins, but yet ampicillin is commonly used to treat Listeria. (In fact, Listeria is why ampicillin is added to neonatal meningitis regimens.) I'm not sure how to reconcile this.
95
Describe some key features of the on-off Parkinsonism seen with long-term carbidopa/levodopa therapy.
* Does not correlate with drug levels (i.e., is unpredictable)
* Tends to worsen and does not always spontaneously resolve
* Drug holidays have not been shown to be helpful
96
There are three mechanisms of hypercalcemia in malignancy:
• PTHrp (SCC, breast, ovarian, and renal cancers)
• Direct osteolytic growth (multiple myeloma)
• ________________ (lymphomas)
Enhanced production of vitamin D leading to calcium absorption
97
Which of the dyslipidemia drugs cause gallstones?
Cholestyramine (gull bringing bile rocks down from lobster) and fibrates (island with rocks behind jellyfish)
98
What is the classic presentation of Rett syndrome?
* Occurs in girls (XLD)
* Normal development until roughly six months followed by regression and loss of previously acquired milestones (for instance, a girl might lose the ability to babble or sit up that she had at five months)
99
What are the clear areas in clear cell carcinoma?
RCC accumulates lots of glycogen and lipids. Standard histologic preparation dissolves these tissues, leaving clear cells behind.
100
What happens first in Paget's disease of the bone?
Aberrant osteoclast activation
It's thought that something triggers osteoclast activation – such as decreased osteoprotegerin or increased RANK-L from an unknown source – and then the osteoclasts get activated. The osteoblasts then overcompensate and lead to a sclerotic phase.
101
True or false: Mallory-Weiss tears arise from acid reflux.
False. They arise from vomiting, which is not considered a kind of acid reflux.
102
You likely remember that koilocytes have a cleared out cytoplasm. There are, however, two other cellular characteristics of koilocytes that can help direct you to a diagnosis of HPV: __________________.
a "raisinoid" nucleus and irregular staining in the cytoplasm (meaning the cytoplasm might be blue in parts but clear in others)
103
What are ectopic rests?
Pieces of embryonic tissue that persist in the developing fetus
104
What causes annular pancreas?
Abnormal migration of the ventral pancreatic bud
The ventral bud normally rotates around to the right of the body and then behind (270º) to form the main duct. If part of it adheres to the foregut, then it can cause a ring around the duodenum that leads to bilious emesis.
105
What is the difference between pericardial rubs and knocks?
Rubs are found in acute pericarditis and knocks are found in chronic pericarditis
106
What is Kussmaul's sign?
A paradoxical increase in JVP with inspiration caused by constrictive pericarditis
107
Progesterone withdrawal causes what two things that lead to menstrual flow?
* Release of MMPs that causes degradation of the ECM
| * Apoptosis of the endometrium
108
What two immune roles do eosinophils have?
* They release major basic protein when they bind IgE on helminths (a form of antibody-dependent cytotoxicity).
* They secrete prostaglandins, leukotrienes, and cytokines in the late-stage type I hypersensitivity.
109
What can be produced by the G6PD pathway?
* Reversible oxidation occurs first and makes NADPH (used in fatty acid synthesis and glutathione reduction).
* Irreversible oxidation takes ribulose 5-phosphate – produced by reversible oxidation – and makes fructose 5-phosphate for glycolysis or nucleotides.
110
Thiamine is a cofactor for which four enzymes?
* Pyruvate dehydrogenase
* Alpha-ketoglutarate dehydrogenase
* Branched ketoacid dehydrogenase
* Erythrocyte transketolase
111
UMP is made from what two constituents?
PRPP and orotic acid
112
Orotic aciduria without hyperammonemia indicates a defect in which enzyme?
UMP synthase
Ornithine transcarbamylase deficiency will present with hyperammonemia. UMP synthase uses orotic acid and PRPP to make UMP (precursor to TMP and CMP).
Giving uridine helps these patients.
113
What two adverse effects does EPO have?
* Thromboembolic events (pretty obvious why)
| * Hypertension (thought to be due to EPO binding to receptors on vascular smooth muscle)
114
Which kind of hemoglobin moves closest to the anode in hemoglobin electrophoresis?
Hemoglobin without mutations
Sickle cell will be farther from the anode because the missense mutation is neutral (the normal glutamate is negatively charged and thus moves toward the positive anode).
Farthest from the anode is HbC which has a lysine mutation and is attracted to the negative cathode.
115
Describe Osgood-Schlatter disease.
* Commonly presents in the insertion of the quadriceps on the tibial tuberosity
* Repetitive contraction of the quadriceps can lead to the patella pulling the tibial apophysis to make it more prominent
116
Which part of the visual field is transmitted by the optic tract?
The homonymous side – the right visual field as seen in both eyes
117
Afferent pupillary defects can occur in any part distal to _______________.
the lateral geniculate nucleus (so the optic tract or optic nerve)
118
ATP binding to myosin causes ________________________.
myosin to detach from actin
Hydrolysis of ATP to ADP causes a conformational change that readies myosin to bind again to actin. The power stroke occurs when hydrolyzed ADP is released from myosin.
119
Which nerve mediates leg adduction?
Obturator nerve
120
The nerve that mediates leg flexion also contains what sensory distribution?
The femoral nerve mediates sensation on the anterior thigh
121
If you see an isodense consolidation behind the psoas muscle, it is possibily ________________.
a retroperitoneal hemoatoma
122
The femoral nerve exits the spine through the _____________ muscle, so anything that disrupts this muscle can cause femoral nerve neuropathy.
psoas
123
Describe the structure of lipopolysaccharide and which part is immunogenic (causes shock).
LPS is a lipid-carbohydrate molecule anchored in the outer membrane of Gram-negative bacteria. Lipid A is anchored in the membrane. The core polysaccharide is attached to lipid A. The O antigen polysaccharide is attached to the core antigen.
Lipid A is endotoxin and is responsible for activating the immune cascade that leads to sepsis.
124
True or false: even people with COPD whose SpO2 saturations are in the 90s can have erythrocytosis.
True! Mild COPD can lead to stimulated erythropoietin.
125
________________ can often occur after a subarachnoid hemorrhage. There might be focal neurologic deficits.
Vasospasm
Note: this occurs due to impaired autoregulation.
126
Phase _____________ is blocked by calcium-channel blockers. Phase ____________ is blocked by potassium-channel blockers.
2; 3
127
A patient's urine turns dark purple after sitting for a bit in the open. What enzyme are they missing?
Porphobilinogen deaminase
128
Calcium requires _______________ to be absorbed. Thus, medications that alter this can raise risk of fracture.
low pH (because calcium carbonate is insoluble)
129
Why does phenytoin cause osteoporosis?
All inducers of CYP450 increase the catabolism of vitamin D.
130
Thickening of the capillary wall is associated with ______________ nephropathy.
membranous
131
The gonadal arteries arise from the ___________________.
abdominal aorta
| Here's a good mnemonic: "The Arteries Arise from the Aorta, while the left vein Returns to the Renal vein."
132
True or false: in bacterial vaginosis, the causative organism is a Gram-negative coccobacilus.
False. Gardnerella vaginella is a Gram-variable rod.
133
What is a case-series study?
A study that follows patients with known conditions to determine natural history or response to treatment
134
How can you tell whether a trisomy originated during meiosis I or meiosis II?
Meiosis I leads to the production of two 2n gamete intermediates; those gametes have two copies of the same chromosome. Meiosis II produces four n gametes: two copies of each chromosome.
Meiosis I trisomies – which are more common – result from failure of anaphase I. As such, one gamete will have all four copies of one chromosome and the other will have none. After meiosis II, there will be two eggs without that chromosome and two eggs with two NON-HOMOLOGOUS copies.
Meiosis II trisomies result from the failed separation of homologous chromosomes. (Remember, meiosis II starts with two 2n gamete intermediates that contain two copies of the same chromosome.) Because the separation that failed was trying to separate two copies of the same chromosome, children with that trisomy will have two HOMOLOGOUS copies.
(Think: "meiosis TWo nondisjunction leaves you with TWin chromosomes.")
135
Anaphylaxis results from the widespread release of what two molecules?
* HIstamine (responsible for vasodilation and increased vascular permeability)
* Tryptase
136
Hyperthyroidism can result from which type of malignancy in males?
hCG-secreting choriocarcinoma
137
Describe how IgE binding leads to activation of mast cells.
Binding of one mast cell receptor to the Fc portion of IgE does not lead to activation. However, if multiple receptors aggregate in a certain area – such as would happen if an antigenic substance had multiple antigen sites that could bind IgE – then degranulation occurs. (This is also referred to as crosslinking.)
138
In addition to mediating the voluntary control of the urethral and anal sphincters, the pudendal nerve also ____________________.
carries sensory fibers from the skin of the penis
139
Injury to the prostatic nerve plexus can lead to _________________.
erectile dysfunction
140
Upper extremity numbness, tingling, and weakness of the medial hand that worsens when the arms are lifted overhead likely indicates what syndrome?
Thoracic outlet syndrome
This occurs when the lower brachial plexus – predominantly the ulnar roots – gets pinched in the scalene triangle. The scalene triangle is made by the middle and anterior scalene muscles and the first rib. When the arms are raised, the first rib disrupts the ulnar roots. Because the subclavian artery and vein are also nearby, exertional arm pain (from occlusion of the artery) and arm swelling (from occlusion of the vein) can be a component of TOS.
141
You know that GU is the 5' splice site (in mRNA) and AG is the 3' splice site. What proteins mediate splicing?
Small nuclear ribonucleoproteins (snRNPs)
142
Normal PaCO2 in a patient with DKA likely indicates _________________.
respiratory failure
Recall that (using Winter's formula) PaCO2 should be decreased in metabolic acidosis. (The formula is PaCO2 = [1.5 x HCO3] +8 +/- 2.) Some patients can get respiratory fatigue and thus develop respiratory acidosis on top of metabolic acidosis.
143
If you are speaking with a child and the parent will not let the child speak (by constant interruption), the best course of action is to ___________________.
ask the parent to leave
144
You're well familiar with heart failure cells (hemosiderin-laden macrophages). What histologic test is specifically down that identifies these?
They look golden-brown and then turn blue when Prussian blue is added.
Note: Prussian blue highlights iron.
145
What patients are at higher risk for negative reactions to succinylcholine?
A little background: succinylcholine is a depolarizing acetylcholine mimetic. It binds to nonselective cation channels that can allow sodium in or potassium out.
Those with neuromuscular problems – such as quadriplegia, Guillain-Barre, or myopathies – usually have upregulated NMJ choline channels. Because of this, they are at increased risk of a syndrome in which succinylcholine can cause the efflux of potassium, which induces arrhythmia.
As such, vecuronium or atracurium are safer choices for those with neuromuscular problems.
146
True or false: episiotomies usually cut through the anal sphincter.
False. In episiotomies, an incision is made through the perineal body – the tendinous membrane between the anus and the vagina. The anus is left intact because the perineal membrane is the main restriction on the opening of the vaginal exit.
Note: the levator ani is left intact because that goes around the anogenital hiatus. Also, the transverse perineal muscle – which connects to the sides of the perineal body – is also left intact.
147
If a patient with cognitive impairment has repeated hospitalizations due to failure to comply with medications, how might you better reduce the risk of another rehospitalization?
Consult social work to identify potential causes of medicaiton non-compliance.
148
True or false: routine replacement of catheters is done to limit the likelihood of catheter-associated infection.
False. Routine changing of central catheters has not been shown to decrease infection (neither has prophylactic antibiotic use or daily application of topical antibiotics).
The only things that have been shown to decrease the rate of CLABSI is proper sterile technique – such as use of alcohol wipes and hand sanitizer prior to donning sterile gloves – and using the subclavian artery or jugular vein (as opposed to the femoral artery which has a higher infection rate).
149
Immunity to ________________ can wane in adults who have not gotten boosters.
Pertussis
150
True or false: Pseudomonas is immobile.
False. Just like the running Dalmatian in the Sketch, it can move!
151
When creatine kinase rises after a thrombus is lysed, the damage is referred to as __________________.
a reperfusion injury
Note: the mechanism is not agreed upon, but is thought to perhaps involve neutrophils being attracted to ischemic tissue and releasing destructive molecules, oxidative damage, or mitochondrial stress after ischemia.
152
Tetanus is usually diagnosed by _________________.
history and physical
There is no serum assay or culture for tetanus because it causes damage in extremely small amounts that can be localized to the injury site and nearby nerves.
153
In addition to alopecia, vincristine can also cause __________________.
peripheral neuropathy; like Chediak-Higashi, vincristine use results in microtubule dysfunction which impairs the transport of neurotransmitters
154
If a woman has purulent discharge from the cervix without cervical motion tenderness, what is the likely organism that caused this?
Cervicitis can present with vaginal bleeding, mucopurulent discharge from the cervix, and friable cervix WITHOUT cervical motion tenderness. In fact, the most common presentation is incidental.
The two most common organisms are N. gonorrhoeae and C. trochomatis.
155
Other than antidiarrheals, what things can cause toxic megacolon?
Anything that damages the colon – such as C. difficile or IBD – can damage the muscles of the colon and lead to paralysis. This can then lead to toxic megacolon even without inflammatory diarrhea because the commensal bacteria can overgrow.
TM is a well-known complication of untreated ulcerative colitis.
Abdominal plain films are the preferred diagnostic.
