CONCEPT REVIEW (ENDOCRINE) Flashcards
The endocrine system releases hormones to control body activities and help maintain ____________?
homeostasis.
What is a HORMONE?
A molecule that is released in one part of the body but regulates the activity of cells in other parts of the body.
Exocrine gland secretions enter ducts that carry the secretions to body surfaces or into cavities. ________ glands secrete hormones into interstitial fluid to diffuse into the blood where they circulate to target tissues.
Endocrine
The secretion of hormones is regulated by ?
the nervous system,
chemical changes in the blood,
and other hormones.
Hormones affect only_____________ that have specific receptors to bind to a given hormone. The number of hormone receptors may decrease (downregulation) or increase (upregulation).
target cells
There are two classes of hormones:
lipid-soluble and water-soluble.
____________ hormones circulate in blood plasma unattached to plasma proteins; most ___________ hormones circulate attached to transport proteins
Water-soluble, lipid-soluble
What can Hormones do? Functions?
Hormones can stimulate synthesis of molecules, alterations in membrane permeability, stimulation of membrane transport, alterations in metabolic rate, and contraction of smooth and cardiac muscle.
Three factors influence the responsiveness of a target cell to a hormone?
the hormone’s concentration,
abundance of target cell receptors,
and influences exerted by other hormones.
How are Hormones regulated?
Hormone secretion is regulated by nervous system signals, chemical changes in the blood, and other hormones.
How many hormones are regulated by the Hypothalamus?
The hypothalamus regulates anterior pituitary secretion of seven important hormones.
Secretion of anterior pituitary hormones is stimulated by ____________ hormones and suppressed by___________hormones from the hypothalamus. These hypothalamic hormones reach the anterior pituitary through the _________________ that links the hypothalamus and the anterior pituitary.
releasing, inhibiting, hypophyseal portal system
What are tropic hormones?
Several anterior pituitary hormones are tropic hormones, hormones that influence the secretion of other endocrine glands.
The 7 main Hormones of the Anterior Pituitary
- Adrenocorticotropic hormone (ACTH)
- Corticotropinreleasing hormone (CRH)
- Human growth hormone (hGH)
- Thyroidstimulating hormone
- Folliclestimulating hormone (FSH)
- Luteinizing hormone (LH)
- Prolactin
Oxytocin and antidiuretic hormone originate in the _____________ and are stored in the posterior pituitary.
hypothalamus
The thyroid gland is located ?
inferior to the larynx and anterior to the trachea.
What are the 3 major THYROID hormones.
Internally, the gland consists of thyroid follicles with follicular cells that produce two thyroid hormones: triiodothyronine (T3) and thyroxine (T4),
and parafollicular cells that produce calcitonin.
The parathyroid glands secrete parathyroid hormone, which regulates what ions ?
calcium, magnesium, and phosphate ion levels.
The paired adrenal glands lie superior to each kidney. Each adrenal gland has an outer adrenal _______ and inner adrenal __________.
cortex, medulla.
The adrenal cortex secretes mineralocorticoids, glucocorticoids, ________________?.
and weak androgens
The major mineralocorticoid, aldosterone, does what functions?
increases kidney reabsorption of Na+ and water from
urine to the blood,
increases excretion of K+ into the urine,
and helps adjust blood pressure and blood volume.
Secretion of aldosterone is controlled by the reninangiotensinaldosterone pathway.
The glucocorticoids (mainly cortisol) regulate what?
metabolism and resistance to stress
Secretion of glucocorticoids is initiated by corticotropinreleasing hormone from the hypothalamus, which stimulates release of ACTH from the anterior pituitary. Glucocorticoids increase protein breakdown, enhance glucose formation, break down triglycerides, inhibit inflammation, and ___________________________.
depress immune system responses
Androgens function to?
stimulate growth of axillary and pubic hair, aid prepubertal growth spurts, and contribute to libido in females.
Secretes epinephrine and norepinephrine?
The adrenal medulla
These hormones augment the sympathetic nervous system fightorflight response.
The ovaries produce what hormones ?
Estrogens, Progesterone, and Inhibin
The testes produce what hormones ?
Testosterone and Inhibin.
The pineal gland is attached to the roof of the third ventricle in the brain. It secretes the what hormone?
melatonin
Body tissues other than those normally classified as endocrine glands contain endocrine tissue and secrete hormones, what organs are they?
gastrointestinal tract, placenta, kidneys, skin, and heart.
