16. The Endocrine System

For a nerve impulse to travel from one neuron to another, the signal must be transmitted across a synapse. At the synapse, the axon releases a neurotransmitter that then diffuses across the synapse and activates receptors on the subsequent dendrite. While this is an example of a nervous signal using a neurotransmitter, the action of neurotransmitter at a synapse is also sometimes considered an example of what other type of signaling?

Epinephrine (also known as adrenaline) is produced by your adrenal cortex during stressful situations. The adrenal cortex is part of the adrenal gland, located just superior to the kidneys. One of the targets for adrenaline is the heart, where it increases the heart rate. Based on this description, what type of signaling molecule is adrenaline?

Between the statements below, which one correctly describes a significant difference between how the endocrine and nervous systems function?

True or False: if false, choose the answer that best corrects the statement.

Target cells can be defined as cells that possess a receptor that binds a particular hormone.

The use of a chemical messenger to transfer information from cell to cell within a single tissue is referred to as _____ communication.

(a) Direct

(b) Paracrine

(c) Hormonal

(d) Endocrine

More than one choice may apply. Which is generally true of hormones?

a. Exocrine glands produce them.

b. They travel throughout the body in the blood.

c. They affect only non–hormone-producing organs.

d. All steroid hormones produce very similar physiological effects in the body.

FSH production in males supports:

(a) The maturation of sperm by stimulating nurse cells

(b) The development of muscles and strength

(c) The production of male sex hormones

(d) An increased desire for sexual activity

All of the following are true of the endocrine system, except that it:

(a) Releases chemicals into the bloodstream for distribution throughout the body

(b) Releases hormones that simultaneously alter the metabolic activities of many different tissues and organs

(c) Produces effects that can last for hours, days, and even longer

(d) Produces rapid, local, brief-duration responses to specific stimuli

(e) Functions to control ongoing metabolic processes.