Almost all hormone secretion is regulated through the mechanism of _______. The endocrine system’s use of this mechanism is a key factor in producing homeostasis in the human body, meaning its maintenance of a relatively _______ internal environment.

The part of the brain called the_______ controls much of the activity of the endocrine system through its regulation of hormone release in three glands, the _______and ________ pituitary glands and the medulla of the _______ glands.

Five of the six hormones produced by the _______pituitary gland control the release of hormones produced by________.

Hormones are substances secreted by one set of ________ that move through the ________and affect the activities of other

Hormone production takes place to a significant extent within _______ glands, defined as glands that release their materials directly into the _______ or surrounding tissue, without the use of ducts.

Hormones can be thought of as coming in three principal classes: _______based, _______, and ________ hormones. The largest class of hormones is the _____ hormones, while the slowest acting are the ________hormones.

Pancreatic beta cells can sense high levels of circulating glucose and, in response, secrete insulin, which helps move glucose out of circulation. These cells can likewise sense the resulting low circulating glucose levels, and when they do, they reduce their secretion of insulin. This is negative feedback in action; the product of beta cell activity (insulin) ultimately has the effect of reducing beta cell activity. Why does the body constantly utilize negative feedback to maintain the stable state called homeostasis? Why couldn’t it use positive feedback instead?

As defined in the text, hormones (select all that apply):

a. tend to be secreted by glands.

b. affect mostly fat, muscle, and liver cells.

c. have effects only on target cells.

d. are distributed by traveling through the bloodstream.

e. have almost instantaneous effects.

The text makes clear that hormones play critical roles in allowing us to function each day. So why are they commonly thought of as substances that cause us to act in unusual ways?

Endocrine glands secrete their materials:

a. into ducts.

b. into synapses between nerve axons and cell bodies,

c. directly into cells.

d. directly into the bloodstream or surrounding tissues.

e. into the digestive tract.

Steroid hormones are all _____ and generally bind to receptors____.

a. produced in greater amounts by males; on muscle cells

b. built around the framework of the cholesterol molecule; on fat cells

c. composed of chains of amino acids; on a target cell’s outer or plasma membrane

d. built around the framework of the cholesterol molecule; inside target cells

e. muscle-building hormones; on muscle cells