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66 Cards in this Set
- Front
- Back
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exocrine glands
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secrete products into ducts, ducts carry secretions to target site
ex: sweat, oil, mucous, digestive glands |
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endocrine glands
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secrete products (hormones) into interstitial fluid of secretory cells, then diffuses into capillaries (carried away by blood)
ex: pituitary, thyroid, adrenal, pineal glands |
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hormones
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released in 1 pt of the body, but regulate the activity of cells in other parts of the body
specific target cells (w/ specific receptors) highly regulated carry info powerful effects even in very low concentrations |
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hormones help regulate
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-extracellular fluid
-metabolism -biological clock -contraction of cardiac & smooth muscle -glandular secretio -some immune functions -growth and developmen -reproduction |
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circulating hormones
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endocrine hormones that travel in the blood, act on distant target cells
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paracrine hormones
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local hormones that travel in extracellular space (not in blood), act on neighboring cells
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autocrine hormones
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local hormones that travel in extracellular space, act on same cell that secreted it
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general mechanisms of hormone action
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1. hormone binds to receptor on cell surface OR receptor inside target cell
2. cell may then -synthesize new molecules -change permeability of membrane -alter rates of reactions 3. each target cell responds to hormone differently |
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lipid-soluble hormones
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bind to TRANSPORT PROTEINS to be carried in the blood
ex: steroids, thyroid hormones, and NO use DIRECT GENE ACTIVATION bind to and activate receptors WITHIN cells |
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direct gene activation
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mechanism of lipid-soluble hormones
1. lipid soluble hormone diffuses into cell 2. activated receptor-hormone complex alters gene expression 3. Newly formed mRNA directs synthesis of specific proteins on ribosomes 4. new proteins alter cell's activity |
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water-soluble hormones
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circulate freely in plasma (no transporter required)
ex: amines; peptides; proteins; glycoproteins; eicosanoids 2nd messenger activation |
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second messenger activation
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mechanism of water-soluble hormones
hormone can't diffuse through plasma membrane 1.binding of hormone (1st messenger) to its receptor activates G protein, which activates adenylate cyclase 2. activated adenylate cyclase converts ATP to cAMP 3. cAMP serves as a 2nd messenger to activate protein kinases 4. activate protein kinases phosphorylate cellular proteins 5. millions of phosphorylated proteins cause reactions that produce physiological responses |
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Amplification of Hormone Effects
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- single molecule of hormone binds to receptor
- activates ~100 G proteins - each G-protein activates an AC, which then produces ~1000 cAMP -each cAMP activates a protein kinase which may act on ~1000+ substrate molecules |
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stimuli that provoke the endocrine gland to start the production-secretion process
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humoral- (blood or fluid)- inc glucose in the blood causes the release of insulin by the pancreas
neural- a preganglionic sympathetic nerve fiber stimulates the adrenal medulla to secrete catecholamines hormonal- pituitary gland secretes TSH that in-turn causes the thyroid gland to release T3 and T4 |
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regulation of hormone levels in the blood
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-amt of ea. hormone in the blood varies from min. to min.
-constant change in amt and type of stimuli (humoral, neural, hormonal) -regulated by feed-back loop mechanisms |
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the master gland
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aka the pituitary gland
affects many other hormones/physiologic functions (maturation, growth, reproduction, circulation, bone metabolism, etc) |
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hypothalamus
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the major integrating link b/w the nervous and endocrine systems
receives input from cortex, thalamus, limbic system & internal organs controls pituitary gland w 9 dif releasing and inhibiting hormones with the pituitary gland- regulates virtually all aspects of growth, development, metabolism & homeostasis |
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hGH
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most plentiful anterior pituitary hormone
essential for normal growth during childhood & adolescence promotes synthesis & secretion of small protein hormones called insulin-like growth factors (IGFs) IGFs stimulate growth and regulate metabolism |
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how hGH and ICF stimulate growth
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- common target cells: liver, skeletal muscle, cartilage, bone
- inc growth & cell division by increasing AA uptake and protein synthesis - stimulate lipolysis, fatty acids used for ATP' - spares use of glucose for ATP production |
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giantism
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hypersecretion of hGH during childhood, normal body proportions
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acromegaly
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excess hGH during adulthood
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hormones released by the thyroid gland
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T4- thyroxine
T3- triiodothyronine Calcitonin |
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thyroxine
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aka T4, more secreted
less biologic activity some converted to T3 |
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triidothyronine
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aka T3, less secreted
more biologic activity higher concentration in blood |
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physiological roles of thyroid hormones (through gene activation)
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1. metabolic (mitochondria) inc O2 consumption, inc ATP production, inc production of heat, inc BMR (Basal Metabolic Rate)
2. Growth and Development [brain, bone, muscle tissue]- stimulate protein synthesis & accelerate tissue growth 3. neuroendocrine -enhance effects of: epinephrine, glucagon, growth hormone ENERGY FOR GROWTH |
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hyperthyroidism
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-burn too much energy
-weight loss -feeling hot -fatigue, irritability, jittery feeling & behavior - treatment: radioactive iodine, ablation |
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hypothyroidism
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less metabolic activity
more common -weight gain -feeling cold -fatigue, slowed thinking, lethargy -treatment: TSH |
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stimuli which cause T4 and T3 releas
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-low blood levels of T4 and T3 (feedback loop)
-low metabolic rate -increase in ATP demand (cold temps, inc'd energy expenditure, hypoglycemia, high altitude, pregnancy) |
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exopthalamos
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example: graves' disease
excess thyroid hormones |
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goiter
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enlargement of thyroid gland
often associated w/ iodine deficiency |
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calcitonin
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3rd thyroid hormone
regulates calcium homeostasis -determines where calcium should be lowers blood levels of calcium; puts calcium into tissues inhibits bone resorption by osteoclasts builds bone, incorporates calcium into bone matrix |
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Parathyroid hormone
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PTH
regulates homeostasis of calcium & phosphate -inc blood calcium level -dec blood phosphate level inc # and activity of osteoclasts Promotes bone resorption and release of Calcium stimulates the kidneys to release calcitrol and cause reabsorption of Ca2 from food |
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calcitrol
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stimulated by the parathyroid hormone (PTH)
kidneys secrete _____ which stimulates increased absorption of Ca2 from foods, which increases blood Ca2 level |
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outer cortex of adrenal glands
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produce 3 types of hormones from 3 zones of the cortex:
1.mineralocorticoids (e.g. aldosterone) 2. glucocorticoids (e.g. cortisol) 3. androgens |
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inner adrenal medulla
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produces catecholamines (~80%epinephrine, ~20% norepinephrine)
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aldosterone
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INC reabsorption of Na+ and H20, puts it back in the blood
INC secretion of K+ and H+ Goal: regulate Na+ and K+ levels in the body and regulate water balance regulated by : renin-angiotensin pathway |
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renin angiotensin pathway
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1. deficiency of Na+ or hemmorhage
somehow leads to.... 5. decreased renin 7. decreased angiotensin I 11. increased aldosterone from adrenal cortex 12. increased Na+ and water reabsorption |
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CORTISOL metabolism & stress response
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muscle fibers--> protein brkdwn (energy)
liver-->gluconeogenesis (energy) adipocytes--> lipolysis (energy) blood arterioles-->vasoconstriction (pressure increases, circulation inc) WBC--> inhibition of WBC and Anti-inflammatory effects (slows healing) ** want for organ transplant to dec immune response |
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cushing's syndrome
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hormonal disorder caused by prolonged exposure of the body tissues to high levels of cortisol
rare disease releasing too much energy that you're not using so u store it store fat in dangerous areas; thin and fragile skin and fragile bones; weakness, fatigue, irritation, high blood glucose, high BP |
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Epinephrine
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~80% of hormones released by adrenal medulla
inc substrate use and mobilization inc glycogen brkdwn inc lipolysis ((more energy-related)) |
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Norepinephrine
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~20% of hormones released by adrenal cortex
((cardiovascular effects)) inc HR inc force of contraction inc BP inc blood flow to <3, liver, muscle, adipose tissue dilation of airways obtaining & delivering of oxygenated blood |
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stimuli for the release of catecholamines
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1. increase in Sympathetic NS activity
2. drop in blood sugar 3. decreases in blood glucose levels 4. low energy levels |
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epipen
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shot of epinephrine
strong vasoconstrictor action counters vasodilation rapid onset & short duration of action cause bronchial smooth muscle relaxation |
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stress: general adaptation syndrome
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1. Fight or Flight (Immediate)
2. Resistance (Longer-term) 3. Exhaustion (depletion...death) |
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step 2 resistance -General Adaption Syndrome
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ACTH-->Adrenal glands-->releases cortisol--> lipolysis, gluconeogenesis, protein catabolism, sensitized blood vessels, reduced inflammation
hGH--> liver--> IGFs--> lipolysis, glycogenolysis TSH--> thyroid gland -->T3 and T4--> inc'd use of glucose to produce ATP |
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insulin
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released from pancreatic beta cells
promotes glucose uptake from blood (decreases blood glucose) stimulates glycogenesis another role: AA uptake from blood |
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glucagon
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released from pancreatic alpha cells
promotes RELEASE of glucose into the blood stimulates glycogenolysis |
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insulin-glucose 'cycle'
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blood glucose (and thus these hormones) is affected by the food we eat
CHO in our food increases blood glucose hormone levels in the blood are constatnly going up and down, changing to meet the needs of more or less glucose in the blood |
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uptake of AA from blood-function of insulin
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promotes protein synthesis
lipogenesis and glycogenesis (store energy) slows GNC and glycogenolysis important during youth and puberty |
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Type 1 Diabetes
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Insulin Dependent DM
"juvenile onset" ~10% absolute deficiency of insulin autoimmune disease, body destroys beta cells treatment: insulin injection; pancreatic beta-cell transplant |
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Type 2 Diabetes
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Non-Insulin Dependent DM
"adult onset" insulin produced, tissues insensitive t insulin, down-regulation of insulin receptors (become resistant) --insulin won't work, cant get glucose out of blood and into cell treatment: may need insulin; diet modification; weight loss |
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symptoms of diabetes mellitus
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excessive urine production (polyuria)
excessive thirst (polydipsia) excessive eating (polyphagia) acetone breath, hyperpnea, nausea/vomiting/abdominal pain, cardiac irregularities, central nervous system depression, coma (result of lipolysis and ketogenesis) |
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lipidemia
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too much fat in the blood
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why weight regulation/exercise is important in treating Type II
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- reg exercise increases glucose uptake (it is its own stimulant) [exercise mediated glucose uptake]
- adipose tissue releases hormones that make you more insulin resistant |
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Luteinizing Hormone MEN
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stimulate Leydig cells to secrete testosterone (enzyme converts testosterone into dihydrotestosterone, more potent)
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FSH Follicle Stimulating Hormone MEN
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-stimulates spermatogenesis
-w/ testosterone, stimulates SERTOLI cells to secrete ABP (androgen-binding protein) -testosterone stimulates final steps of spermatogenesis |
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Inhibin
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produced by sertoli cells
if sperm production is sufficient: sertoli cells release inhibin, inhibits FSH secretion by the anterior pituitary, decreases sperm production -->more inhibin, less FSH, less ABP, less sperm production If sperm production is proceeding too slowly: less inhibin is released by the sertoli cells, more FSH will be secreted, sperm production will be increased |
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testosterone
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-controls the growth, development, functioning and maintenance of sex organs
-stimulates bone growth, protein anabolism, and sperm maturation -stimulates development of male secondary sex characteristics |
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FSH female functions
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initiates the formation of follicles/eggs w/in the ovary
stimulates follicle cells to secrete estrogen 'codes' for 1 egg to be released this hormone is highest during the first 0-6days |
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LH functions female
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stimulates ovulation
promotes the formation of the corpus luteum which secretes estrogens, progesterone, relaxin and inhibin |
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estrogens
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-promote development and maintenance of female reproductive structures and secondary sex characteristics
-increases protein anabolism and builds strong bones -lowers blood cholesterol -moderate levels of these inhibit release of GnRH, LH and FSH -cardio protecting |
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1st half of Female Reproductive Cycle
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Follicular phase-->prepares egg
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2nd half of Female Reproductive Cycle
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Cuteal Phase
-progesterone and estrogens -lining keeps growing in case there is a fertilized egg (lining grows due to release of estrogen) |
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progesterone
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needs to remain high to sustain pregnancy
highest from days 20-24ish can take injections if need be |
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look at LH level
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to predict ovulation
it is the highest ~day 13 |
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steps of ovulation
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1. high levels of estrogens from almost mature follicule stimulate release of more GnRH and LH
2. GnRH promotes release of FSH and more LH 3. LH surge brings about ovulation (need spike in LH to have ovulation) |
