Biochemistry and Physiology Quiz 2

Hormone classes (Endocrines)

A medical student is sorting hormones by chemical class. Which of the following is correctly classified as an amino-acid–derived hormone, rather than a peptide or steroid hormone?

Source of nitrogen for the urea cycle (Metabolism)

Which compound most directly donates nitrogen for incorporation into urea in the urea cycle?

Liver enzymes (Biological compounds / Clinical chem)

Elevated serum aminotransferases are noted in a patient with acute hepatitis. Which pattern is most typically shared by acute hepatitis, myocardial infarction, and acute hemolytic anemia?

Renin–angiotensin–aldosterone system (Renal / Circulation)

Angiotensin II has several physiologic effects that help restore blood pressure in volume depletion. Which of the following is NOT a major action of angiotensin II?

Compensation for decreased blood pressure (Circulation)

A sudden drop in arterial blood pressure is sensed by baroreceptors. Which of the following responses would NOT be expected as a compensatory change?

Local regulators of arteriolar tone (Circulation)

Which local chemical change in tissues would least likely promote arteriolar vasodilation?

Renal clearance (Renal)

Under normal physiologic conditions, which substance has the lowest renal clearance?

Aminotransferases & organ damage (Metabolism)

An alcoholic patient develops fatty liver and hepatocellular injury. Which serum finding best supports ongoing hepatocyte damage due to increased transamination reactions?

Baroreflex & posture (Circulation)

A healthy person suddenly stands up from a supine position. Which immediate physiologic change is primarily mediated by the baroreceptor reflex?

Membrane transport & insulin (Molecular/cellular physiology)

Which glucose transporter is upregulated by insulin in skeletal muscle and adipose tissue to increase glucose uptake?

Action potential phases (Nervous system)

During the upstroke (phase 0) of a typical neuronal action potential, which channel event is primarily responsible?

Muscle physiology (Muscle)

In skeletal muscle, what event directly triggers the power stroke of the myosin head?

Hemoglobin–O₂ dissociation (Respiration)

Which of the following conditions would shift the hemoglobin–oxygen dissociation curve to the right, favoring oxygen release to tissues?

Acid–base compensation (Respiration / Renal)

A patient with diabetic ketoacidosis presents with a low blood pH and decreased plasma bicarbonate. Which compensatory response is expected?

Connective tissue matrix (Connective tissue)

Which component of connective tissue is primarily responsible for resisting compressive forces due to its high water-binding capacity?

GI hormones (Digestion / Physiology)

Which hormone is released from the duodenum in response to fatty chyme and stimulates gallbladder contraction and pancreatic enzyme secretion?

Pituitary and growth (Endocrines)

A child’s long-bone epiphyseal plates show markedly reduced growth. Deficiency of which gland’s hormone is the most likely cause?

Cell membranes & insulin (Membranes)

Which statement about cell membranes is most accurate?

Hunger regulation (Endocrines / Oral physiology)

Which hormone is primarily responsible for stimulating appetite and is often elevated before meals?

Renin–angiotensin & lab values (Renal / Data link)

A patient with severe volume depletion has an elevated BUN:creatinine ratio. Which mechanism best explains this finding in the context of angiotensin II activity?