Question 1

Which of the following best describes the role of second messengers in hormone signaling?

Accepted Answer

They are intracellular molecules that relay signals from hormone-receptor complexes to initiate cellular responses.

Question 2

A patient is experiencing high blood pressure due to increased renin secretion. Which pathway is most directly activated by renin?

Accepted Answer

Renin stimulates the formation of angiotensin II, which increases aldosterone and ADH secretion.

Question 3

Which hormone is secreted by the pineal gland and is responsible for regulating circadian rhythms?

Accepted Answer

Melatonin

Question 4

Which of the following is a peptide hormone that stimulates red blood cell production in response to low oxygen levels?

Accepted Answer

Erythropoietin (EPO)

Question 5

A researcher is studying the effects of cyclic AMP ($cAMP$) in target cells. Which enzyme is responsible for converting ATP to $cAMP$?

Accepted Answer

Adenylate cyclase

Question 6

Which of the following best explains the negative feedback mechanism in endocrine regulation?

Accepted Answer

Hormone secretion is inhibited when the desired physiological effect is achieved.

Question 7

Which hormone is released by the heart and acts to reduce blood volume and pressure?

Accepted Answer

Atrial natriuretic peptide (ANP)

Question 8

A patient has a deficiency in insulin production. Which pancreatic cells are most likely affected?

Accepted Answer

Beta cells

Question 9

Which of the following hormones is classified as a steroid and is produced by the testes?

Accepted Answer

Testosterone

Question 10

Which process is directly inhibited by phosphodiesterase in the $cAMP$ signaling pathway?

Accepted Answer

Degradation of $cAMP$ to AMP

Question 11

A patient is unable to concentrate urine due to a deficiency in antidiuretic hormone (ADH). Which gland is most likely malfunctioning?

Accepted Answer

Posterior pituitary gland

Question 12

Which hormone stimulates the synthesis and secretion of hormones in the anterior lobe of the pituitary gland?

Accepted Answer

Releasing hormones (RH)

Question 13

Which of the following is a correct sequence for the activation of a second messenger system involving $cAMP$?

Accepted Answer

Hormone binds receptor → G protein activated → Adenylate cyclase activated → ATP converted to $cAMP$

Question 14

Which hormone is secreted by the kidneys in response to decreased blood oxygen levels?

Accepted Answer

Erythropoietin (EPO)

Question 15

Which of the following is a function of melatonin?

Accepted Answer

Inhibits reproductive function and protects against free radicals

Question 16

Which hormone is released by the adrenal cortex and is involved in sodium retention?

Accepted Answer

Aldosterone

Question 17

A patient with low blood calcium levels is likely to have increased secretion of which hormone?

Accepted Answer

Parathyroid hormone (PTH)

Question 18

Which of the following best describes the function of releasing hormones (RH) secreted by the hypothalamus?

Accepted Answer

They stimulate the synthesis and secretion of hormones in the anterior pituitary.

Question 19

Which hormone is responsible for stimulating follicle development in the ovaries?

Accepted Answer

Follicle-stimulating hormone (FSH)

Question 20

Which of the following is a direct effect of atrial natriuretic peptide (ANP) released by the heart?

Accepted Answer

Promotes excretion of sodium and water by the kidneys

Endocrine System: Hormones and Regulation – Study Notes for Anatomy & Physiology

Study Guide - Practice Questions