Question 1

Which of the following best describes a key difference between the nervous system and the endocrine system?

Accepted Answer

The nervous system acts at specific locations determined by axon pathways, while the endocrine system acts at diffuse locations where blood reaches.

Question 2

Which of the following is NOT a function controlled or integrated by the endocrine system?

Accepted Answer

Initiation of voluntary muscle contraction

Question 3

Which statement correctly distinguishes exocrine glands from endocrine glands?

Accepted Answer

Exocrine glands produce nonhormonal substances and have ducts to carry secretion to membrane surface.

Question 4

Which organ is considered a neuroendocrine organ?

Accepted Answer

Hypothalamus

Question 5

Which of the following is a correct example of a chemical messenger classified as an autocrine?

Accepted Answer

A chemical that acts on the same cells that secrete it

Question 6

Which of the following is NOT a class of hormone?

Accepted Answer

Glycoproteins

Question 7

What is the primary mechanism by which water-soluble hormones exert their effects on target cells?

Accepted Answer

Activation of plasma membrane receptors and G protein second messengers

Question 8

Which of the following steps occurs first in the cyclic AMP (cAMP) second-messenger mechanism?

Accepted Answer

Hormone binds to receptor

Question 9

In the PIP$$_2-$$calcium signaling mechanism, which molecule acts as a second messenger to release Ca$$^{2+}$$ from intracellular storage sites?

Accepted Answer

Inositol triphosphate (IP$$_3)$$

Question 10

Which of the following is a direct effect of calcium-bound calmodulin in the PIP$$_2-$$calcium signaling pathway?

Accepted Answer

It activates enzymes that amplify the cellular response.

Question 11

Which of the following best describes the action of lipid-soluble hormones?

Accepted Answer

They bind to intracellular receptors and directly activate genes.

Question 12

Which process is initiated when a lipid-soluble hormone binds to its intracellular receptor?

Accepted Answer

Initiation of DNA transcription to produce mRNA

Question 13

Which feedback mechanism most commonly controls hormone release?

Accepted Answer

Negative feedback

Question 14

Which type of endocrine gland stimulus involves changing blood levels of ions and nutrients directly stimulating hormone secretion?

Accepted Answer

Humoral stimuli

Question 15

Which of the following is an example of a neural stimulus for hormone release?

Accepted Answer

Sympathetic nervous system fibers stimulate adrenal medulla to secrete catecholamines.

Question 16

Which factor does NOT influence target cell activation by a hormone?

Accepted Answer

Rate of hormone synthesis in the liver

Question 17

What is the effect of up-regulation in target cells?

Accepted Answer

Target cells form more receptors in response to low hormone levels.

Question 18

Which of the following best defines the half-life of a hormone?

Accepted Answer

The time required for the level of hormone in blood to decrease by half

Question 19

Which interaction describes when one hormone cannot exert its effects without another hormone being present?

Accepted Answer

Permissiveness

Question 20

Which of the following is an example of synergism in hormone action?

Accepted Answer

Glucagon and epinephrine both cause the liver to release glucose.

The Endocrine System: Overview and Mechanisms (Chapter 16, Part A)

Study Guide - Practice Questions