Question 1

Which of the following best describes the difference between autocrines, paracrines, and hormones?

Accepted Answer

Autocrines act on the same cell that secretes them, paracrines act on nearby cells, and hormones travel through the bloodstream to distant targets.

Question 2

Amino acid-based hormones typically exert their effects through which of the following mechanisms?

Accepted Answer

Second messenger systems such as cAMP

Question 3

Which hormone is produced by the pancreas as an endocrine product?

Accepted Answer

Insulin

Question 4

Which of the following is a correct sequence of events in the cAMP second messenger system?

Accepted Answer

Hormone binds receptor → G protein activated → Adenylate cyclase activated → cAMP produced → Protein kinases activated

Question 5

Steroid hormones are synthesized from which precursor molecule?

Accepted Answer

Cholesterol

Question 6

Which of the following best explains why steroid hormones require transport proteins in the blood?

Accepted Answer

They are hydrophobic and do not dissolve well in plasma.

Question 7

A patient is given a pharmacological dose of a hormone for several weeks. Which of the following is most likely to occur in their target cells?

Accepted Answer

Down-regulation of hormone receptors

Question 8

Which of the following is an example of a hormone interaction known as antagonism?

Accepted Answer

Insulin lowers blood glucose while glucagon raises it

Question 9

Which of the following best describes the control of hormone release by humoral stimuli?

Accepted Answer

Hormone secretion in response to changing blood levels of ions or nutrients

Question 10

A patient with a tumor that secretes excess ACTH would likely have which of the following effects?

Accepted Answer

Increased secretion of corticosteroids from the adrenal cortex

Question 11

Which of the following hormones is NOT secreted by the anterior pituitary (adenohypophysis)?

Accepted Answer

Antidiuretic hormone (ADH)

Question 12

Which of the following best describes the role of the hypothalamo-hypophyseal portal system?

Accepted Answer

It carries releasing and inhibiting hormones from the hypothalamus to the anterior pituitary.

Question 13

Which of the following is a direct effect of growth hormone (GH) on metabolism?

Accepted Answer

Promotes lipolysis and inhibits glucose uptake by cells

Question 14

Which of the following best explains the negative feedback regulation of thyroid hormone?

Accepted Answer

Rising levels of thyroid hormone inhibit the release of TRH and TSH

Question 15

Which hormone is responsible for stimulating milk production in the breasts?

Accepted Answer

Prolactin (PRL)

Question 16

Amino acid-based hormones such as epinephrine and norepinephrine are classified as which type of hormone?

Accepted Answer

Catecholamines

Question 17

Which of the following is a correct statement about the mechanism of action of steroid hormones?

Accepted Answer

They bind to intracellular receptors and directly influence gene transcription.

Question 18

Which of the following is an example of a hormone released in response to neural stimuli?

Accepted Answer

Epinephrine from the adrenal medulla

Question 19

Which of the following best describes the permissiveness interaction between hormones?

Accepted Answer

One hormone cannot exert its effects without another hormone being present

Question 20

Which of the following is a function of luteinizing hormone (LH) in males?

Accepted Answer

Stimulates interstitial cells of the testes to produce testosterone

Endocrine System: Structure, Function, and Hormone Mechanisms

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