Questions Flashcards
(345 cards)
What molecules is POMC (pro-opiomelanocortin) a precursor of?
Adrenocorticotropic hormone (ACTH) and beta-lipotropin (B-LPH)
Various melanocyte stimulating hormones happen next in the pathway.
What class of antibiotics are also motilin agonists?
Macrolides to include erythromycin and azithromycin
What is the rate cutoff for distinguishing between AIVR and ventricular tachycardia?
180 bpm
What type of organism is most likely to result in a Type II immune response? What cells are associated with such a response?
Parasites / helminths
CD4+ TH2 cells, eosinophils, basophils, mast cells
What is the ryanodine receptor, and what receptor is it attached to?
It is a protein located in the wall of the sarcoplasmic reticulum. It is connected to a dihydropyridine receptor located in the wall of the T tubule. When the AP travels down the T tubule, it changes the DHP receptor, which then open the ryanodine receptor, allowing calcium out of the sarcoplasmic reticulum.
What does vitamin D toxicity cause the serum phosphorus and calcium to do? What is the biologically active form of vitamin D? Does this increase or decrease PTH activity?
It causes hypercalcemia and hyperphosphatemia.
1,25-dihydroxycholecalciferol
Decreases PTH activity (negative feedback since PTH activates it in the kidney)
Describe the pathway for norepinephrine production.
The amino acid tyrosine is converted to dopamine, which is then converted to norepinephrine.
What commonly used antibiotics concentrate within the urine?
Aminopenicillins
Other commonly used in people include TMS, nitrofurantoin and fluoroquinolones
What class of antibiotics is best used to treat actinomycosis?
Penicillins
What is the mechanism of action of calcitonin?
Inhibits osteoclast activity (doesn’t directly decrease parathyroid activity)
What pharmacokinetic value determines the extent of exposure of a drug over time following its administration?
AUC
Where are bile acids reabsorbed along the GIT? What is this pathway called?
Ileum
Enterohepatic circulation
What value is higher in chylous effusions than in serum, and should be measured to confirm a diagnosis of chylous effusion?
Triglycerides
CD25 is associated with what type of T cell?
T regulatory cells
What do the following hormones do in regards to increasing or decreasing fatty acid release?
- Epinephrine
- Growth hormone
- Thyroid hormone
- Glucagon
- Insulin
- Epinephrine - increase
- Growth hormone - increase
- Thyroid hormone - increase
- Glucagon - increase
- Insulin - decrease
Where is glucagon manufactured?
The pancreatic alpha cells
What does the parietal cell secrete?
Hydrogen protons (with Cl)
In people, intrinsic factor is also secreted from the parietal cells.
What hormones increase pancreatic secretions?
Acetylcholine, secretin and cholecystokinin
What is the mechanism of action for sildenafil?
It is a phosphodiesterase V inhibitor. This blocks degradation of the second messenger cAMP, and ultimately increases NO production.
What is the pathophysiologic mechanism behind foxglove toxicity?
This is a cardiac glycoside, with the same MOA as digoxin - inhibition of Na-K-ATPase pump. This results in intracellular accumulation of Na and Ca - positive inotropy occurs, but also significant arrhythmias, often bradyarrhythmias. Vomiting and lethargy are common.
Which diuretic is potassium sparing? Why are the other ones potassium wasting?
Spironolactone. This inhibits aldosterone action on the principal cells in the distal nephron, preventing K secretion.
Other diuretics are primarily potassium wasting because they increase flow through the nephron, lowering the amount of potassium seen by the principal cells, favoring a concentration gradient to move potassium out of the principal cells into the urine.
What causes acetylcholine to be released from the pre-synaptic neuron terminal?
Influx of calcium into the neuron via voltage gated calcium channels triggered by the action potential reaching the nerve terminal.
What is the Frank-Starling law of the heart?
Increased volume in the ventricle (ie preload) stretches the cardiac myocytes / sarcomeres out to a longer length, facilitating a stronger heart beat. The farther stretched the sarcomeres are, the more they can contract and more blood they can move.
What is the form of babesia that causes RBC lysis?
Merozoites, which form from asexual reproduction of the sporozoites which invaded the RBC.