mixed deck 04/17

Question 1

male neonates XY with 5alpha reducaste deficiency

Answer 1

are born with feminized external genitalia, but male internal and are typically masculinze at puberty. a small phallus and hypospadias are commonly found

Question 2

The earliest lesion of atherosclerosis?

Answer 2

intimal (fatty) streaks, the earliest lesion of atherosclerosis, are composed of intimal lipid filled foam cells, which are derived from macrophages and smooth muscle cells that have engulfed lipoproteins and predominantly LDL

Question 3

phentolamine

Answer 3

is a reversible, competitive, nonspecific a-adrenergic antagonist used in the management of cathecolamine induced HTN crisis.
BUT high doses of NE can overcome its competitive antagonistic effects

phenoxybenzamine is irreversible competitive antagonist and would not be completely overcome by NE

Question 4

most common cause of death in patients with DM?

Answer 4

coronary heart disease

Question 5

Burkitt lymphoma t(8:14)

Answer 5

diffuse medium sized lymphocytes and high proliferation index represented by a high KI-67 fraction
-starry sky appearance is due to presence of benign macrophages

Question 6

TCA overdose –> refractory hypotension and cardiac arrhthmias

Answer 6

-side effects:
inhibition of sodium channels in cardiac myocytes
(fast sodium channel conduction)

Question 7

TCA inhibitor effects:

Answer 7

• central and peripheral muscarinic Ach receptors–> tach, delirium, dilated pupils, flushing, decreased diaphoresis, hyperthermia, intestinal ileus, urianry retension
• peripheral a-1-adrenergic receptors–> vasodilation –> orthostatic hypotension
• cardiac fast sodium channels–> conduction defects, arrhthmias, hypotension
• presynaptic NE and 5-HT reuptake –> seizures, tremors
• H1 receptors —> sedation

Question 8

Cutanous lymph drainage from the umbilicus to the feet including the external genitalia and anus (up to the dentate line) drain into?

what is the exclusion?

Answer 8

superficial inguinal lymph nodes

the posterior calf is the exclusion and drains to the popliteal lymph nodes

Question 9

Sarcoidosis, chest xrays and staging

Answer 9

Stage 1L
reveal bilateral hilary lymphadenopathy
stage II:
bilateral hilar lymphadenopathy along with pulmonary infiltrates commonly in the upper lobes
Progression of the disease leads to disappearance of hilar lyphadenopathy
stage III
lung infiltrates only
stave IV
lung fibrosis

Question 10

serotonins precurser?

Answer 10

tyrptophan

tripsy your beagle stealing seretonin turkey at your table

Question 11

serotonin sydrom

Answer 11

• neuromuscular excitation: hyperreflexia, clonus, myoclonus, rigidity, tremor
• autonomic stimulation: hyperthermia, tachycardia, diaphoresis and vomiting/diarrhea
• altered mental status: agitation and confusion

Question 12

How to treat serotonin syndrome

Answer 12

• supportive care including airway maintenance, hydration and temperature maintenance
• Cyproheptadine is a serotonin receptor antagonist which is a first generation histamine antagonist with non specific 5-HT1 and 5-HT2 receptor antagonistic properties

Question 13

How to diminish cystplatins nephrotoxicity?

Answer 13

AMIFOSTINE is a thiol based cytoprotective free-radical scavenging agent

Question 14

When using benzos watch out for other drugs with sedative effects. Name those drugs

Answer 14

-First generation H1-histamine receptor antagonists cause significant sedations.
diphenhydramine and chlorpheniramine

Question 15

How do bronchial veins return blood to the heart?

Answer 15

• small portion via the azygous, accessory hemiazygous or intercostals veins.
  -majority of blood supplied to bronchial arteries is returned to the left heart in deoxygenated form via the pulmonary veins
  0this causes an admixture of blood and would should a decrease in oxygenation in the LA versus the capillaries of the respiratory system

Question 16

Intersussception

Answer 16

• most common in younger children <2 : often without any structural cause (sometimes associated with viral infections).
• in patients older than 2, a lead point such as meckel diverticulum, foreign body, or intestinal tumor should be sought

clinical:
colicky, intermittent abdominal pain, nausea, vomiting and currant jelly stools.

Question 17

Cystinuria with cystine stones

Answer 17

• defect in renal PT
• decreased resorption of the amino acid cystine (2 cysteines)
• recurrent stone formation from a younger age
• urinalysis with show pathognomoic hexagonal cystine crystals
• the sodium cyanide-nitroprusside test detects cytine sulfhydryl groups and is diagnostic

Question 18

volume of distribution of a drug

Answer 18

hypothetical volume of fluid into which the administered amount of drug would need to be uniformly distributed to produce the observed plasma concentration.

Question 19

Vd=

Answer 19

amount of drug given (mg)/plasma concentration of drug (mg/L)

Question 20

Low volume of distribution 4-8L

Answer 20

high M.W. , high plasma protein binding, high charge and high hyrdophilicity tend to trap the drug in the plasma compartment resulting in a low Vd

Question 21

60-40-20 rule

Answer 21

60% of the body weight is water
40% in intracellular
20% is extracellular
1/3 of water weight is extracellular

of the the extracellular fluid 1/4 is plasma volume and 3/4 is interstitial fluid.

41L of fluid in the body ~14L is extracellular and ~3L is in plasma

if a drug is large it will be bound extensively to plasma proteins or charged (hydrophilic) it will remain in the plasma compartment and the volume of distribution will be as low as ~3-5L