Endocrine System Flashcards
differences between the nervous and endocrine systems (5)
1) hormones delivered to tissues throughout the body by blood vs neurotransmitters released locally in response to nerve impulses
2) mediator action is far from the site of release;binds to receptors on or in target cells vs being close to the site of release, at a synapse;binds to receptors in postsynaptic membrane
3) types of target cells are cells throughout the body vs muscle (smooth, cardiac and skeletal) cells, gland cells, other neurons
4) time to onset action is seconds to hours to days vs within milliseconds
5) duration of action lasts longer (seconds to days) vs generally short term (milliseconds
what does the infundibulum do?
connects the pituitary gland to the hypothalamus
anterior pituitary gland is a ____ endocrine gland
true
what does the posterior pituitary gland contain?
axon terminals of hypothalamic neurons
the hypothalamus controls the secretion of____
hormones secreted by the anterior pituitary
median eminence
where the regulatory hormones are produced in the hypothalamus (releasing and inhibiting hormones
hormones enter the ___ ____ _____ to regulate the activity of endocrine cells in the ____ _____ gland
hypophyseal portal system, anterior pituitary
human growth hormone (hGH) or somatotropin
stimulates the liver, muscle, cartilage, bone, and other tissues to synthesize and secrete insulinlike growth factors (IGFs) they promote growth of body cells, protein synthesis, tissue repair, lipolysis, and elevation of blood glucose concentration
thyroid-stimulating hormone (TSH) or thyrotropin
stimulates the synthesis and secretion of thyroid hormones by the thyroid hormones by the thyroid gland
follicle-stimulating hormone (FSH)
in females: initiates development of oocytes and induces ovarian secretion of estrogens
in males: stimulates testes to produce sperm
luteinizing hormone (LH)
in females: stimulates secretion of estrogens and progesterone, ovulation and formation of corpus leteum
in males: stimulates testes to produce testosterone
prolaction (PRL)
together with other hormones, promotes milk secretion by the mammary glands
adrenocorticotropic (ACTH) or corticotropin
stimulates secretion of glucocorticoids (mainly cortisol) by the adrenal cortex
melanocyte-stimulating hormone (MSH)
exact role in human is unknown but may influence brain activity; when present in excess, can cause darkening of skin
anterior pituitary secretes
hGH, TSH, FSH, LH, PRL, ACTH, MSH
hypothalamus secretes
releasing and inhibiting hormones into portal circulation, these regulate the secretion of anterior pituitary hormones
what do the supraoptic nuclei produce?
anti-diuretic hormone/ vasopressin
what do the paraventricular nuclei produce?
oxytocin
posterior pituitary hormones
Oxytocin (OT), Antidiuretic hormone (ADH) or vasopressin
oxytocin
stimulates the contraction of smooth muscle fibers of the uterus during childbirth; stimulates contraction of the cells in mammary glands to cause milk ejection
ADH/vasopressin
conserves body water by decreasing urine volume; decreases water loss through perspiration; raises blood pressure by constricting arterioles
where is the pineal gland located?
the brain, near the roof of the 3rd ventricle
pineal gland job
secretes melatonin, which is involved in setting the body’s biological clock, levels rise during sleep
thymus produces____
thymyosin, thymic humoral factor, thymic factor, thymopoietin that promote proliferation and maturation of T cells
thyroid produces____
thyroglobulin, T3 (triiodothyronine) and T4 (thyroxine)
thyroid follicles job
make, store and secrete thyroid hormone
C cells produce ____
calcitonin
calcitonin does what?
decreases plasma calcium levels
______ _____ surround colloid in a ______
follicular cells, cavity
where are the thyroid hormones located?
in the colloid
where is the parathyroid gland located?
posterior surface of the thyroid gland
parathyroid gland produces
parathyroid hormone (PTH)
what does PTH do?
raises plasma calcium
how does PTH raise plasma calcium?
1) increases bone matrix breakdown
2) increases reabsorption in the nephron
3) increases intestinal absorption (via increased vitamin D activity)
how does CT decreases plasma calcium levels?
inhibits bone reabsorption by osteoclasts and by accelerating uptake of calcium and phosphates into bone ECM
what do the thyroid hormones do?
increases basal metabolic rate, stimulate synthesis of proteins, increases use of glucose and fatty acids for ATP production, increase lipolysis, enhance cholesterol excretion, accelerates body growth, and contributes to development of the nervous system
name the layers of the adrenal glands superficial to deep
capsule, adrenal cortex, adrenal medulla
adrenal cortex produces…
hormones essential for life, loss of adrenocortical hormones leads to death in a few days
adrenal medulla produces and secretes…
2 neurohormones,
1) norepinephrine
2) epinephrine
adrenal cortex secretes…
1) aldosterone
2) cortisol
3) androgens
name the layers of the adrenal cortex from superficial to deep
zona glomerulosa, zona fasciculata, zona reticularis
aldosterone is secreted from the _____ _____ layer of the _____ _____
zona glomerulosa, adrenal cortex
cortisol is secreted from the _____ _____ layer of the _____ _____
zona fasciculata (thickest), adrenal cortex
androgens are secreted from the _____ _____ layer of the _____ _____
zona reticularis, adrenal cortex
what does aldosterone do?
increases blood levels of sodium levels and decreases blood levels of potassium levels acts on the kidney
what does cortisol do?
increases protein breakdown, decreases inflammation and help combat stress response, depress immune response,
what do androgens do?
assist in axillary and pubic hair, estrogen in menopause, etc.
what do the adrenal medulla hormones do?
produce effects that mimic those of the sympathetic division of the autonomic nervous system (ANS) during stress
cell bodies of the hypothalamus make…in how many nuclei
oxytocin and ADH , 2
where is oxytocin made?
in the paraventricular nucleus
where is ADH made?
in the supraoptic nuclei
axons of the cell bodies in the hypothalamus go through the ______ _____ that ends near the ______ of the _____ _____
hypothalamophyseal tract, capillaries, posterior pituitary
where does the posterior pituitary secrete these hormones into?
the capillaries near the posterior pituitary
different types of cells in pancreas
1) alpha cells
2) beta cells
3) delta cells
4) F cells
what do alpha cells secrete?
glucagon
what do beta cells secrete?
insulin
what do delta cells secrete?
somatostatin
what do F cells secrete?
pancreatic peptide
glucagon
raises blood glucose levels by accelerating the breakdown of glycogen into glucose in the liver, converting other nutrients into glucose in live, and releasing glucose into the blood
insulin
lowers blood glucose levels by accelerating the transport of glucose into cells, converting glucose into glycogen and decreasing glycogenolysis and glucogenesis , also increases lipogenesis and stimulates protein synthesis
somatostatin
inhibits secretion of insulin and glucagon and slows absorption of nutrients from the gastrointestinal tract
pancreatic polypeptide
inhibits somatostatin secretion, gallbladder contraction, and secretion of pancreatic digestive enzymes
ovarian hormones
progesterone and estrogen
what do progesterone and estrogen do?
together with gonadotropic hormones of the anterior pituitary, regulate the female reproductive cycle, maintain pregnancy, prepare the mammary glands for lactation, and promote development and maintenance of female secondary sex characteristics
testicular hormones
testosterone
what does testosterone do?
stimulates the descent of the testes before birth, regulates production of sperm, and promotes development and maintenance of male secondary sex characteristics
GI tract hormones
gastrin, glucose-dependent insulinotropic peptide (GIP), secretin, cholecystokinin (CCK)
secretin
stimulates the secretion of pancreatic juice and bile
CCK
stimulates secretion of pancreatic juice, regulates the release of bile from the gallbladder and brings about a feeling of fullness after eating
gastrin
promotes the secretion of gastric juice and increases movements of the stomach
GIP
stimulates release of insulin by pancreatic beta cells
kidney hormones
renin, erythropoietin, calcitrol
renin
part of a sequence of reactions that raises blood pressure by bringing about vasoconstriction and secretion of aldosterone
erythropoietin(EPO)
increases rate of red blood cell formation
calcitrol
=an active form of vitamin D, aids in the absorption of dietary calcium and phosphorus
heart hormones
atrial natriuretic peptide (ANP)
ANP
decreases blood pressure
adipose tissue hormones
leptin
leptin
suppresses appetite and may increases the activity of FSH and LH
