Section 39.4.3 (Exam 4) Hormones Flashcards
Hormones Regulate Metabolism and the Internal Environment
What are the two parts of adrenal gland?
adrenal medulla and adrenal cortex
What does the adrenal medulla produce?
two amine hormones called epinephrine (adrenaline) and norepinephrine (noradrenaline)
What does the adrenal medulla develop from and what controls it?
Developed from nervous tissue and is controlled by the nervous system
What does the adrenal cortex produce and what controls it?
Produces steroid hormones
Under the control of anterior pituitary
What are the type of steroid hormone that the adrenal cortex produces?
Corticosteroids
What are the three types of corticosteroids and their functions?
Mineralocorticoids influence salt and water balance
Glucocorticoids influence blood glucose concentration
Sex steroids (produced in negligible amounts in adults)
Name one mineralocorticoid and its function.
Aldosterone stimulates kidneys to conserve Na and excrete K
Name the main glucocorticoid and describe its function.
Cortisol mediates metabolic stress responses
Name three ways cortisol, the main glucocorticoid, mediates metabolic stress respones.
Responses are similar to those of epinephrine in the fight-or-flight response, but are slower and last longer
Inhibits the immune system
Adaptive in responding to acute stress, but cause problems if sustained over time
What organ/hormone controls the release of cortisol from the adrenals?
Anterior pituitary via corticotropin (ACTH, adrenocorticotropic hormone)
How is ACTH release controlled?
Corticotropin-releasing hormone (CRH) released from the hypothalamus
How is acute stress response turned off?
Negative feedback of cortisol to the brain stops the hypothalamus from releasing CRH and stops the anterior pituitary from releasing ACTH
What do epinephrine and norepinephrine released by the adrenal medulla bind to?
adrenergic receptors on target cells
What are the two types of adrenergic receptors?
Alpha-adrenergic receptors respond more to norepinephrine
Beta-adrenergic receptors respond equally to both epinephrine and norepinephrine
Describe the pineal gland.
Located between the cerebral hemispheres, secretes the hormone melatonin in a daily rhythm
Coordinates daily rhythms of physiological functions
In many species, it coordinates seasonal changes such as reproduction timing, migration, preparations for cold weather, etc.
