Mix4

Question 1

Characterize the acid base disorders that would occur from acute salicylate intoxication:

Answer 1

Typically presents with nausea/vomiting, confusion, tinnitus, fever, and tachypnea. Has 2 different stages:

1. Respiratory Alkalosis : happens first as salicylates directly stimulate the medullary respiratory center, causing increased ventilation and loss of CO2 in expired air.
2. Anion gap metabolic acidosis : Starts about 12 hrs after the initial ingestion. High [ ] of salicylates cause lipolysis, uncouple ox phos, and inhibit the TCA cycle. Causes accumulation of organic acids in blood (ketoacids, lactate, pyruvate)&raquo_space; ^ anion gap acidosis.

Question 2

___ are a group of cell adhesion molecules expressed by endothelial cells during the inflammatory response. They function to bind leukocytes, allowing them to exit the blood vessels at the site of inflammation

Answer 2

selectins

Question 3

What is the enzyme that is defective in chronic granulomatous disease?

Answer 3

NADPH Oxidase - normally functions to transfer an e- from NADPH to oxygen&raquo_space; production of superoxide (O2-) and subsequent formation of other ROS [hydroxyl radicals and H2O2]. These oxidants have direct microbial activity and also cause activation of granule proteases that destroy engulfed bacteria.

Question 4

What pathogens do you have to look out for in CGD?

Answer 4

Those bacteria and fungi that create catalase to destroy their own H2O2. (i.e. Staph aureus, Burkholderia cepacia, S maracens, Nocardia, and Aspergillus).

Question 5

The thymus and the inferior parotid gland arise from the ___ pharyngeal pouch:

Answer 5

3rd

Question 6

By what cell mech does Epi prevent insulin release from panc Beta cells?

Answer 6

The a2-AR inhibits insulin secretion while the B2-AR stimulates insulin secretion. The a2-AR normally predominates, so sympathetic stimulation (as by Epi) would lead to an overall inhibition of insulin secretion.

Question 7

Would parasymp stimulation promote or inhibit insulin release?

Answer 7

Promotes insulin release because M3 musc R promotes insulin release and is induced by the sight/smell of food (this is why pilocarpine can make you drool too, body is getting ready for incoming food with parasymp stimulation).

Question 8

PThe phrenic nerve, which is derived from C3-C5, delivers motor innervation to the diaphragm and carries pain fibers from the ___ and ___ pleura.

Answer 8

diaphragmatic and mediastinal pleura.

Question 9

The anatomical snuffbox is a shallow depression in wrist that is bordered by the tendon of the ___ medially and the ___ and ___ tendons laterally.

Answer 9

extensor pollicis longus is medial

abductor pollicis longus and extensor pollicis brevis laterally

Question 10

Which of the carpal bones in the hand are most at risk for avascular necrosis and nonunion when broken?

Answer 10

Scaphoid. Because of its unusual blood supply, the dorsal scaphoid branch of the radial artery supplies the majority of the scaphoid bone, but blood supply to the proximal pole happens retrograde and can be blocked if interrupted by fracture.

Question 11

Pyruvate carboxylase, acetyl coA carboxylase, propionyl CoA carboxylase, and 3-methylcrotonyl-CoA carboxylase all use what vitamin as a cofactor?

Answer 11

Biotin (B7)

Question 12

Very long chain FA or FA with branch points at odd numbered carbons can’t be metabolized in the mitochondria with beta-oxidation. Instead they are metabolized by special forms of beta oxidation (VLC FA) or alpha oxidation (BCFA) within what cell structure?

Answer 12

Peroxisomes

Question 13

Lesch Nyhan disorder is due to defective HGPRT, causing a problem with purine salvage pathway. As a result, de novo purine synth must ^ to replace the lost bases from ineffective salvage. This ^ de novo activity requires an increase in activity of what enzyme?

Answer 13

PRPP (phosphoribosyl pyrophos) amidotransferase.

This is 1st committed step in de novo purine synth.

Question 14

Deamination of DNA bases (cytosine conversion to uracil, adenine to hypoxanthine) can occur spontaneously or secondary to chemical exposure. What process corrects these mistakes?

Answer 14

Base excision repair. Abnormal bases are recognized and removed by glycosylases without disruption of the phosphodiester backbone. The abasic sites are then removed by endonucleases and replaced with the correct base by DNA Pol.

Question 15

Why can parvo B19 cause aplastic crisis in sickle cell patients?

Answer 15

Parvo B19 replicates in erythrocyte precursors in BM. These cells express P Ag (aka globoside) which is the cellular receptor for B19. Viral replication in the nucleus leads to cell lysis (decreased reticulocyte and RBC)

Question 16

What medication would you use for Pt with treatment resistant schizophrenia or schizophrenia assoc with suicidality?

Answer 16

Clozapine

- Has affinity for dopamine and serotonin R but the MOA is unknown.

Question 17

What severe side effect of clozapine do you need to consistently monitor for?

Answer 17

Agranulocytosis. Need to monitor neutrophil counts.

Question 18

The external branch of the superior laryngeal nerve is at risk during thyroidectomy due to its proximity to the superior thyroid artery and vein. What does this nerve innervate, and what are the consequences of damage to it?

Answer 18

Superior laryngeal nerve innervates the cricothyroid muscle. Damage to this nerve&raquo_space; inability to tense the vocal cords&raquo_space; low, hoarse voice with limited range of pitch.

Question 19

Why is peripheral edema a major side effect of dihydropirine calcium channel blockers?

Answer 19

Because they cause preferential dilation of the precapillary vessels (arteriolar dilation)&raquo_space; Increased capillary hydrostatic pressure and ^ extravasation of fluid into the interstitium.

This is why you should co-admin or treat with an ARB or ACEi (because they cause postcapillary venodilation)

Question 20

What are the criteria for a Dx of polycythemia based onhematocrit measurements in men and women?

Answer 20

Hct > 48 in Fem, and > 52 in Male

Question 21

How can you distinguish between absolute and relative erythrocytosis?

Answer 21

Polycythemia can be the result of a true ^ in RBC mass (absolute erythrocytosis) or a decrease in plasma volume (relative erythrocytosis). Need to look at the RBC directly to differentiate. ^ in total RBC mass indicates absolute erythocytosis. If there is no ^ in RBC mass then the Pt is likely experiencing relative erythrocytosis due to fluid loss (i.e diuretic therapy).

Question 22

What’s the principal diff between first order and zero order kinetics in drug metabolism?

Answer 22

First order kinetics = fixed proportion of drug converted per unit time.

Zero order kinetics = fixed amount of drug is converted to metabolite per unit time (regardless of concentration or dose).

Question 23

What Rx would you give to prevent DVT in pregnancy?

Answer 23

Enoxaparin (Low MW heparin)

Question 24

The obturator externus runs from the obturator foramen of the pelvis to the trochanteric fossa of the femur. What is the function of this muscle?

Answer 24

External rotation of the thigh

Question 25

The quadratus lumborum courses posterior to the psoas muscle. It connects the 12th rib and upper lumbar vertebrae to the iliac crest. What does this muscle do?

Answer 25

Contraction of the quadratus lumborum assists in extension and lateral flexion of the vertebral column.