How do nonsteroid hormones differ from steroid hormones?
answer
nonsteroid hormones act via signal transduction pathways; steroid hormones do not act via signal transduction pathways
***Since they do not enter the cell, nonsteroid hormones act via signal transduction pathways.
question
Which of these is a nonsteroid hormone?
answer
epinephrine and oxytocin
***Both epinephrine and oxytocin are nonsteroid hormones.
question
Receptors for nonsteroid hormones are located in _____.
answer
association with a cell's plasma membrane
***Since nonsteroid hormones do not cross a cell's plasma membrane, their receptors are located in association with the plasma membrane.
question
Which of these extracellular signal molecules could diffuse through a plasma membrane and bind to an intracellular receptor?
answer
estrogen
***Steroid hormones such as estrogen can diffuse through the plasma membrane and bind to intracellular receptors.
question
The primary reason steroid hormones usually act slowly is that _____.
answer
they turn genes on or off and it takes time for gene products to build up or become depleted
***This is the primary reason that steroid hormones usually act slowly.
question
Steroid hormone-receptor complexes act in _____.
answer
the nucleus.
***Steroid hormone-receptor complexes bind to DNA, where they affect transcription.
question
What is the function of endocrine glands?
answer
They release hormones into the bloodstream for distribution around the body
***Endocrine glands release hormones into the bloodstream for distribution to distant cells in the body.
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True or false? The homeostatic system for blood calcium concentration is maintained by the hormones calcitonin and parathyroid hormone.
answer
True
question
Which of the following statements about the pituitary gland is false?
answer
Neurosecretory cells produce hormones that are stored in the anterior pituitary.
***This statement is false; neurosecretory cells produce hormones that are stored in the posterior pituitary.
question
True or false? The pancreas is responsible for producing hormones that maintain the homeostatic levels of glucose in the blood.
answer
True
***The pancreas produces two hormones, insulin and glucagon, which work together to maintain the homeostatic levels of glucose in the blood.
question
How is the production of hormones such as thyroxine and estrogen regulated?
answer
The hypothalamus directs the anterior pituitary to produce hormones that then stimulate or inhibit the production of these hormones.
***The hypothalamus directs the anterior pituitary to produce hormones that regulate other hormones in a variety of endocrine organs, including the thyroid gland and ovaries.
question
Which of the following statements about endocrine glands and the hormones they produce is true?
answer
Aldosterone produced by the adrenal glands controls the reabsorption of sodium ions by the kidneys.
***The adrenal glands sit atop the kidneys and secrete a variety of hormones, including aldosterone, which controls the reabsorption of sodium ions by the kidneys.
question
Gigantism, a condition characterized by exceptionally rapid growth, is sometimes caused by a tumor that induces the gland in which it develops to overproduce a certain hormone. Where would such a tumor be expected to grow?
answer
Pituitary gland
***Since the anterior pituitary produces growth hormone (GH), which has growth-stimulating effects throughout the body, a tumor of the anterior pituitary could produce gigantism.
question
Which of these glands secretes releasing hormones?
answer
hypothalamus
***The hypothalamus secretes both releasing and inhibiting hormones.
question
Which of these hormones are responsible for the "fight or flight" response to danger?
answer
epinephrine and norepinephrine
***These hormones, secreted by the adrenal medulla, are responsible for the "fight or flight" response.
question
Adrenocorticotropic hormone (ACTH) triggers the release of _____ in response to stress.
answer
glucocorticoids
***In response to stress, ACTH stimulates the adrenal cortex to secrete glucocorticoids.
question
_____ are the main male hormones.
answer
Androgens
***Androgens, such as testosterone, are the main male hormones.
question
What hormone promotes water retention by the kidneys?
answer
antidiuretic hormone (ADH)
***A diuretic promotes water loss; thus it makes sense that ADH (secreted by the anterior pituitary) promotes water conservation.
question
Which hormone opposes the action of parathyroid hormone?
