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58 Cards in this Set
- Front
- Back
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explain the process of Adenylate cyclase-cAMP 2nd messenger
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G-protein binds to and activates adenylate cyclase which converts ATP into cAMP; cAMP attaches to inhibitory subunit of protein kinase which activates protein kinase; this phosphorylates enzymes that produce the hormones effects; cAMP inactivated by phosphodieserase
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what do theophylline and caffeine do
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they inhibit phosphodiesterase and prevent cAMP breakdown: this enhances cAMP effects
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describe phospholipase C-Ca2+ 2nd messenger
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-hormone binds to surface receptor, activates G-protein, which activates phospholipase C. Ca++ release promotes hormone effects in target cell
-phospholipase C splits a membrane phospholipid into 2nd messengers IP3 and DAG -IP3 diffuses through cytoplasm to ER, causing Ca2+ channels to open -Ca2+ diffuses into cytoplasm and binds to and activates calmodulin Ca2+ -calmodulin activates protein kinases which phosphorylate enzymes that produce hormones effects |
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describe tyrosine kinase 2nd messenger system
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-binding to receptor proteins
-cytoplasm, dimerization -phosphorylation of receptor -tyrosine kinase now active -phosphorylation of signal molecules -cascade of effects -glucose uptake and anabolic reactions |
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which system is used by insulin (and growth factors) to cause cellular effects
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tyrosine kinase 2nd messenger system
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in tyrosine kinase 2nd messenger system what does activated tyrosine kinase phosphorylates signaling in molecules induce?
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hormones/growth factor effects
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what hormones use 2nd messengers
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1. adenylate cyclase- cAMP
2. phospholipase C-Ca2+ 3. tyrosine kinase |
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what are anterior pituitary hormones called
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trophic hormones
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what so growth hormones target and what does it stimulate
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it targets most tissues of body and it stimulates liver to secrete insulin- like growth factor 1 (IGF-1)
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what is the growth hormone regulates by and what is it inhibited by?
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stimulated by- GHRH (releasing hormone)
inhibited by- somatostatin (both from hypothalamus) |
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what is the function of growth hormone
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promotes protein synthesis, lypolysis and increase blood glucose
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what is a disorder caused by growth hormone
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increased GH while bones are still growing in lengths leads to giantism; increased levels after bones have stopped growing leads to acromegaly. diminished/ lack of GH leads to pituitary dwarfism
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thyroid- stimulating: target tissue, function, and what is it stimulated and inhibited by
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target tissue: thyroid gland
function: promotes growth gland and secretion of thyroxine (T4) and T3 stimulated: TRH inhibited by: thyroid hormones |
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prolactin: targets , function, and inhibited by
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targets: female- ovary, mammary gland
male- possible testis function: female- milk production male- testis more sensitive to LH and FSH? inhibited by: PIH |
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ACTH Corticotropin: target, function, stimulated, inhibited
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target: adrenal cortex
function: stimulates secretion of glucocorticoid hormones stimulate: CRH inhibited: gludodorticoids |
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luteninizing hormone (LH): target, function
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target: female- ovary; male-testis
function: female- stimulates ovulation; progesterone production; converts follicle into corpus leteum male- testosterone production |
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follicle- stimulating hormone (FSH): target and function
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target:
female- ovary; male- testis function: female- formation of follicle in preparation of ovulation, estrogen secretion male- sperm cell production |
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what are LH and FSH know as together
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gonadotropins
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name the hormones in the anterior pituitary glands?
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growth hormones, thyroid-stimulating hormone, Prolactin, adrnocorticotropic hormone (ACTH Corticotrpin),
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name the hormones released from the posterior pituitary glands
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antidiuretic (ADH) hormone, oxytocin,
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ADH- antidiurectic hormone: traget tissure and function
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target tissue: kidneys
function: stimulates H2O reabsorption by kindeys (less H2Olost in urine), which increases blood volume and blood pressure |
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oxytocin: target tissue and function
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target tissue: uterine smooth muscle, mammary glands
function: stimulates contraction of uterine smooth muscle during childbirth. stimulates contractions of the mammary alveoli and ducts to cause milk ejection |
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where are ADH and oxytocin produced? where are they released?
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produced: hypothalamus
released:axon terminals in median emnbinence |
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do axons from hypothalamus enter anterior pituitary?
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no
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what is the hypothalamo- hypophuseal portal system composed of?
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capillary bed, portal venules, venules
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what does the negative feedback inhibition control the secretion of?
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ACTH, TSH, GH, FSH, and LH
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what controls the release of hypothalamic or anterior pituitary hormones
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hormones secreted from target tissue
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what does the removal of target tissues result in?
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an increase in secretion of anterior pituitary hormone.
ex. castration results in elevated secretion of LH and FSH |
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name the 6 releasing/ inhibiting hormones from the hypothalamus
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1. growth hormone-releasing hormone (GHRH)- stimulated GH release
2. somatostatin- inhibits GH release 3. thyrotropin releasing hormone (TRH)- stimulates release of thyroid-stimulating hormone. 4. corticotropin releasing hormone (CRH)- stimulates release of andernocorticotropic hormone (ACTH) 5. gonadotropin releasing hormone (GnRH)- stimulates release of gonadotropins, LH and FSH 6. prolactin inhibiting hormone (PIH, dopamine)- inhibits release of prolactin |
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name the three zones of the adrenal cortex from deep to superficial
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zona reticularis, zona fasciclata, and zona glomerulosa
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true of false:
hormonal effects of epinephrine last 10x longer than norepinephrine |
true
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what is the adrenal medulla innervated by
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preganglionic sympathetic fibers
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what is the adrenal medulla activated by?
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fight or flight response
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what do the hormones released from the adrenal medulla cause?
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increased respiratory rate, increased heart rate, increased HR and cardiac output, general vasoconstriction which increases venous return, and glycogenolysis and lipolysis
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what does stress induce?
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general adaption syndrome (GAS), ACTH and cortisol release, affects physiology negatively
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name the adrenal cortexs hormones and describe what they do
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1. glucocorticoid hormones- regulation of blood glucose levels; anti-inflammatory-depresses antibody and white blood cell production
2. mineralocroticoid hormones- regulation of blood levels of Na+ and K+ 3. sex hormones- weak androgens |
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in thyroid hormones-
attach of one I2= ______________ attch 2 x I2= ______________ |
monoiodotyrosine (MIT)
diiodotyrosine (DIT) |
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what does the coupling of MIT and DIT =______
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T3 (10%)
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coupling of two DITs=________
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T4 thyroxine
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iodide actively transported into follicular cells and converted into _________
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iodine
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what attaches to tyrosines of protein thyroglobulin
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iodine
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what is made when I 2 is attached to thyroglobulin protein
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MIT and DIT and T3 and T4
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T3/T4 switch on genes and:
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1. stimulate protein synthesis;
2. promote maturation of nervous system; 3. increase rate of cell respiration inmost tissues of body (increase basal (resting) metabolic rate |
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what is calcitonin?
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produced by parafollicular cells of thyroid gland. decreases Ca++ blood levels by moving Ca++ from blood to bones. secreted into blood in response to hypercalcemia
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name the major functions and their deficiencies of thyroid hormones T3/T4
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1. stimulate protein synthesis; required for normal body growth: cause secretion of GH. deficiency: slow growth in children
2. required for normal maturation of nervous system in fetus and infant (when brain growing). deficiency: mental retardation 3. required for normal alertness and reflexes at all age. deficiency: mentally and physically slow, lethargic. Excess: restless, irritable, anxious, wakeful 4. control eat production in the basal metabolic state (BMR). Deficiency: Low BMR- sensitive to cold, decreased appetite, myxedema. Excess: high BMR, sensitive to heat, increased appetite, increased catabolism of nutrients, exophthalamos 5. stimulate beta adrenergic receptors for epinephrine and norepinephrine. Excess: mass activation of sympathetic nervous system |
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what causes a Goiter?
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iodine deficiency
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where is the parathyroid hormone(PTH) produced and secreted from
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parathyroid glands (4 small glands located on the posterior surface of the thyroid gland)
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PTH secreted into blood in response to:
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hypocalcemia.
PTH increases blood Ca++ by moving Ca++ from bones, intestines, and kidneys to blood |
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true of false:
PTH is the most important hormones in regulation of blood Ca++ levels |
true
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explain the homeostasis of blood glucose
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a rise in blood glucose stimulates insulin secretion
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describe the relationship between insulin and glucose
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insulin promotes fall in blood glucose by stimulating cellular uptake of glucose and conservation of glucose to glycogen and fat
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when does glucagon secreted
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in response to blood glucose concentration (e.g., fasting)
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what is glycogenolysis?
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stimulation of liver to convert glycogen to glucose and this causes blood glucose levels to rise
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glycogenolysis stimulates hydrolysis (breakdown) of stored fat which releases fatty acids into blood, what is this called?
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lipolysis
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a high blood glucose concentration ____________ insulin and ___________ glucagon secretion and visa verse
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stimulates; inhibits
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what happens after eating cardohydrates
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the rise in blood glucose is corrected by insulin
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what happens during fasting
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the fall in blood glucose is corrected by glucagon
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what does insulin do
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promotes entry of glucose into liver, skeletal muscles and adipose tissue and converts glucose into energy storage molecules (glycogen and fat)
also, increases number of GLUT glucose carriers in cell membranes (facilitated diffusion) |
