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335 Cards in this Set
- Front
- Back
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what does endocrine mean? |
internal secretion
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hormones are secreted in the __
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blood
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in general, hormones __ and __ all physiological processes that essentially constitute the total body function
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integrate and coordinate
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what 5 hormones are responsible for regulating digestion, utilization, and storage of glycogen, protein, fatty acids, and glucose?
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cortisol, GH/IGF1, glucagon, insulin, thryoid hormone
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what (5) hormones are responsible for regulating the internal milieu (body fluids, electorlytes, acid base, and glucose)
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insulin, PTH, ADH, cortisol, aldosteorne
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what 4 hormones are responsible for regulating reproduction? both sexually and behaviorally? |
FSH/LH, estrogen, andorgen, prolactin
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what 6 hormones regulate growth and deveopment of cell proliferation/differentiation, skeletal, and neuronal development?
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estrogen, androgen, GH/IGF-1, vitamin D, cortisol, insulin/glucagon
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what are the three basic types of hormone?
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amino acid derived (epinephrine, thryoxine)steroids (progerstone, estrogen, androgen)protiens (both long peptide chain and short peptide chain) (growth hormone (long) and vasopressin (small))
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how are protein and peptide hormones synthesized?
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complex process of protein synthesisproteins created through translation, processing, and packaging prohormone is converted to a hormone they are stored in secretory vescicles released via exocytosis |
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how are steroid hormones synthesized?
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from acetate or cholersterol by a cascade of enzymes
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steroids can go through the __
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plasma membrane
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steroid hormone synthesis requires __
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enzymatic activity
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amino acid derived hormones are synthesized from __
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tyrosine or phenylalanine via cascade of enzymes
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explain the storage, secretion, and binding of protein hormones
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storage: secretory granulessecretion: exocytosisbinding: specific binding proteins for some hormones
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explain the storage, secretion, and binding of amino acid protiens
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storage: secretory granules (except for thryoid hormones)secretion: exocytosisbinding: no binding protein except for thyroid hormone |
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amino acid hormones undergo __ quickly
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degredation
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explain the storage, secretion, and binding of steroid hormones
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storage: nonesecretion: spontaneousbinding in plasma:albumin and specific globulins
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what happens to free hormones?
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rapidly degraded in target tissues, liver, and kidneys and excreted in the urine, bile, and feces
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which of teh following set of hormones regulates the overall growth and development of the body?A: cortisol, glucagon, thryoid hormoneB: estrogen, vitamen D, cortisolC: insulin, aldoserone, cortisolD: FSH, prolactin, and IGF-1
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B
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what is the main difference between steroid hormonea amino acid hormone production?
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amino acid hormone production is occurring in the secretory vessicles
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how does albumin help regulate hormone?
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by absorbing excess hormones in the blood and storing them
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what two things must a hormone do to induce a cellular action?
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bind to a specific cell surface or intracellular recptor (proteins) evoke hormone specific biologicl action (the receptors biological action)
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why are hormone binding proteins not receptors? |
because they do not evoke a hormone specific intracellular signal. they regulate free hormone levels in the blood
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where are receptors for protein hormones and amines found?
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the cell membrane (exception: the thyroid hormone receptor which is located int eh nucleus)
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where are teh receptors for steroid hormones?
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the cytoplasm or nucleus
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explain down regulation
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the hormone binds to a receptor, evokes a biological action, the receptor and hormone leave the membrane, the hormone is degraded, the receptor returns to the cell membrane
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what 6 things does cellular responsiveness depend on?
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hormone concentrationreceptor numberduration of exposureintervals between consecutive exposures (controlled by down regulation)intracellular conditions (cofactors, enzymes)concurrent presence of antagonistic or synergistic hormones
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explain the protein kinase A system |
hormone binds to the G protein coupled receptorprotein complex attached to GPCR releases (GalphaS, betta, and gamma)GalphaS activates ACAC convets ATP to cAMPcAMP activates protein kinase
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explain the PKC system
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hormone binds to Breleases GalphaQalphaA binds to PLCPLC stimulates PKCDAG stimulates Ca release
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explain steroid hormone action
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steroid hormone binds to a binding proteinsteroid hormone gets into the cellbinds to a receptorgets in the nucleusbinds to DNAstimulates genomic effects
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define negative feedback
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the reaction of a cell to certain stimulus to supresses the action of the cell
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define positive feedback
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the reaction of a cell to a certain stimulus to increase cell action
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is the competition between radiolabed and unlabed ligands for teh anibody. It has teh highest sensitivity. the unknowns are calculated from a standard curve, very involved proccess |
radioimunoassay (RIA)
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a non-competative but non-radioactive and colorimetric matrix used to identify hormones
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enzyme linked immunosorbent assay (ELISA)
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what are the two main methods of detecting hormones?
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radioimmunoassay (RIA) and Enzyme linked immunosorbent assay (ELISA) |
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what are teh two reasons for disorders of teh endocrine system?
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hyperfunction: exessive hormone/above normal activities Hypofunction: hormone deficiency/below normal acitivities
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what is the hypothalamus?
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hormone producing nuclei that affect the pitutitary gland |
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what are the two kinds of hypothalamic horomones?
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releasing hromones that stimulate synthesis and release of anterior pituitary hormones inhibitory hormones that inhibit the syntehsis and release of the anterior pituitary hormones
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what are neurohormones?
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hormones synthesized in teh hypothalamic neurons and stored in the nerve terminal buttons in the posterior pituitary
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hypothalamic hormones are __ peptides that are released from the __ to affect the __
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small, median eminence, anterior pitutitary
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what hormones come from the parventricular nucleus and what do they stimulate? |
TRH (TSH and Prolactin), CRH (ACTH)
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what hormones come from the anterior parventricular nucleus and what do they stimulate?
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somatostatin (inhibitory ie GH)
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what hormones come from the arcuate nucleus and what do they stimulate?
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GHRH (GH), dopamine (inhibitory ie prolactin), GnRH (FSH and LH)
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what hormones come from the posterior pituitary and what do they stimulate?
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ADH, oxytocin
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what are the 6 charactersitics of hypothalamic releasing hormones?
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pulsitile release act via specific plasma membrane receptors use cAMP, phospholipids, and Ca as intracellular signals stimulate hyperplasia and hypertrophy of target cells stimulate the syntesis and release of pituitary hormones regulate their own receptors on target cells and thus modulate their own effects
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what are the two parts of the pituitary gland?
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anterior pituitary (adenohypophysis)posterior pituitary (neurohypophysis)
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the pituitary sites in the __
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sella turcica of the sphenoid bone
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the anterior pituitary lies outside the __
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blood brain barrier
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explain the three types of positive and negative feedback mechanisms
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long loop: target hormones to the pituitary or hypothalamus short loop: pituitary hormones to the hypothalamus ultra short loop: hypothalamic hormones to the hypothalamic neurons via fenestrated endothelial cells
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TRH is a __ hormone
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protein
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explain the pituitary-thyroid axis
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thermal and caloric signals--stimulate TRH release in the hypothalamus--TSH release stimulates synthesis of T3 and secretion of T4 in thryoid gland--T4 can inhibit TRH via long loop feedback
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explain the pituitary adrenal axis
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CRH is secreted in the periventricular nucleus STIMULATED: feeding, depression, anxiety, stress, sleep/wake, Ach, GABA, serotoninINHIBITED: endorphinADH and CRH stimulate anterior pit to secrete ACTHACTH is synthesized from POMC which also produces MSH and endorphinACTH causes adrenal cortex to secrete androgen, aldosterone and cortisolACTH and cortisol inhibit CRH production
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what mechanism does ACTH work by?
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PKA
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explain the pituitary liver axis (GH) |
-STIMULATED BY: arginine, dopamine, alpha receptor agonists, stress, sleep-arcuate nucleus secretes GHRH, along with ghrelin causes ant pit to secrete GH-GH causes biological effect and secretion of IGF1-GH, IGF1, and GHRH stimulate somatostatin release which inhibits GH.-IGF1 also inhibts GH
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explain the 3 actions of GH and the 4 of IGF1 |
GH:-decreases adiposity by decreasing glucose uptake and increasing lipolysis-increases chondrocyte differentiation-increases lean body mass by increasing gluconeogenesis, ICF1 and IGFBP IGF1:-increased plasma glucose and FFA, decreased plasma amino acids and urea-Muscle: decreased glucose uptake, increased AA uptake and protein synthesis-increase in linear growth: increase in chondrocyte cell number and size-increase in organ cell hypertrophy and hyperplasia |
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what are the 5 things that can cause GH deficiency
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-hypothalamic dysfunction-pituitary tumor-abnormal synthesis-receptor disorders-IGF1 malformation
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what three things can happen if there is a GH deficiency before puberty?
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short stature (dwarfism)delayed ossification and pubertal growthmild obesity
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higher level of body fat around the waistanxiety and depression and fatiguehigher than normal levels of LDLS and TGdecreased libidogreater sensitivity to hot/coldless body mass, strength and bone density are all symptoms of __ |
GH deficiency in adults |
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what would occur from an excess of GH before puberty?
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gigantism
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what happens in an excess of GH in adults
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acromegaly
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explain the pituitary mammary axis (prolactin)
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Stimulus: hypoglycemia, exercise, trauma, TRH, surgery, sleep, breast stimulationInhibition: dopaminecauses: proliferation and branching of mammary ducts, alveolar development, postpartum milk protein synthesis
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what are 4 things that would come from hyperprolactinemia?
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impotence, hypothalamic hypogonadism, infertility, galactorrhea
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in FSH and LH, the __ chain is hormone specific
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beta
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LH secretion in teh femal is __, __, and __
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pulsatile, diurnal, cyclic |
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FSH secretion in the femal is __
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cyclic
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explain the pitutitary gonadal axis (FSH and LH)
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FemaleStimulus: NEInhibition: endorphin, serotonin-hypothalamus secretes GnRH -causes ant pit to secrete LH and FSH-LH cause theca cells to secrete progesterone-FSH cause granulosa cells to secrete estradiol-17B inhibins and activin-progesterone and estradiol 17B inhibit hypo-inhibins and activin affect ant pit-E2 can be positive feedback for hypo during ovulation Male:LH affects leydig cells which secrete testosteroneFSH affects sertoli cells to secrete inhibinstestosterone inhibits hypo and pitinhibin inhibts pit
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ADH is a __
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nonapeptide
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ADH is synthesized in the __, transported via the __ and packaged in the __ to be released in the __
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nerve cell body, neurophysin 2, herring bodies, neurohypophysis
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what stimulates and inhibits ADH
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stimulates: Agn II, symp stimulation, hyperosmolarity, hypovolumia, hypotension inhibts: hypoosmolality, increased ECFV, ethanol, ANH
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ADH's vasoactive effects work via teh __ mech while its renal effects work via the __
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PAC, PKA
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oxytocin is synthesized in the __, transported via the __, packaged in teh __, and released in the __
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hypothalamaus, neurophysin 1, herring bodies, neurohypophysis
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oxytocin acts on __ via __ in teh __ |
smooth muscle, Ca, breast and uterus
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what stimulates and inhibits oxytocin production
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stimulation: suckling and myometrial contractioninhibition: stress and depression, catecholamines
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what 5 things do the calcium and phosphate homeostasis depend on? |
intestine, skeleton, and kidneys aided by the skin and liver |
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what regulates calcium and phosphate turnover?
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PTH and calcitonin
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what are the three steps of thryoid hromone syntehsis?
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1.iodide trapping2. iodination of tyrosine on TG to form MIT and DIT3.coupling ofMIT and DIT to form T3 and T4
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explain the process of thryoid hormone synthesis
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-iodide is trapped via the Na/I symporter (powerd by Na/K pump)-TG is synthesized in the epithelium cells and brought to lumen-H2O2 oxidizes I to I2 and iodinates tyrosine on the TG to form MIT and DIT-MIT and DIT are combined by H2O2 to form T3 and T4-TG is stored in the colloid-TSH cause pinocytosis of the TG by pseudopodia-TG is cleaved into T4, T3, MIT and DITT4 and T3 is secreted into bloodstream and MIT and DIT are broken down and recycled
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iodide content in the thryoid glands is __x more than the daily amount needed for hormone syntehsis
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100
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the average daily intake an dexcretion of iodide is __ |
400 micrograms
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increased throid hormone levesl of only __% inhibit TSH secretion, __ is the more potent
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10-30, T3
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explain the autoregulation of TSH (wolff-chikoff effect)
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at low levels of iodide intake, thyroid hormone synthesis is directly proportional to iodide avialability when iodid intake exceeds 2 mg/day, free iodide inhibtis the iodide trap
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what are the effects of tyroid hormone?
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growth:-endochondrial ossification and maturation of epiphyseal bone center-induciton of tooth developement-enhancement of growth cycle of epidermis and hair follicles-inhibits glycoaminoglycans and fibronectin-maitians gonadal functionsCNS:-proliferation of axons-branching of dendrites-myelination of nerve fibers-enhancement of cognitive behaviorCarido:-increase CO-increase HR and contractility-induce syntheis of adrenergic receptorsmetabolism: -increase GI glucose absorption-potentiate the effect of GH and catecholamine on gluconeogenesis, lipolysis, and porteolysisBMR:-increase O2 consumptoin (increase body temp, synthesis of Na/K pump except in brain, gonads and spleen)-increase BMR
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what is the holding protein for T4 and T3
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throxine binding globulin (TBG)
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T4 can be converted to __ by __
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reverse T3, deiodinase enzymes
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T3 can be inactivated to DIT and MIT in target tissues by __
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deiodinase enzymes
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what are two effects of hyperthyoidism?
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graves disease: antibodies mimic TSH at receptorbenign neoplasms: TSH escapes the hypo-pit regulation
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symptoms os hyperthyoidism
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increased weight lossincreased food intakeincreased HRexopthalmos
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what is idiopathic atrophy? (hypothyroidism)
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lymphocytes attack thyroid gland
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low BMR, weakness, bradycarida, myxedema, damage to nerves, loss of hair, anemia, menstrual dysfunction, cretisim in infants are all results of __
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hypothyroidism
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resting Ca is __ |
10^-7 M
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what is the normal plasma calcium concentration is __
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8.6-10.6 mg/dl
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__ increases and __ decreases plasma ionized Ca levels |
acidosis, alkalosis
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what is the normal daily intake of Ca?
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1000
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explain Ca intake and excretion |
1000 mg/day intake, 900 is excreted in feces350 is absorbed, 250 is secreted9980 is filtered and 9880 is reabsorbed
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what is the normal plasma phosphate concentration?
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2.4-4.5 mg/dl
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__ are the majro controlling mechanism for maintining plasma phosphate levels
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renal excretion and reabsoption
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what are the three kinds of bone cells? |
osteoblasts (bone formatoin), osteocytes, osteoclasts (bone reabosroption)
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bone formation is stimulated by __, __, __, __, and __ and inhibited by __ and __
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GH, estorgen, androgen, Vitamin D, calcitonin,PTH< cortisol
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bone reabosrption is stimulated by __, __, and __ and inhibted by __, __, and __
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PTH, cortisol, THestrogen, androgen, calcitonin
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how do osteocytes maintain contact witht he surface osteoblasts and other osteocytes?
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syncytial processes that run through canaliculi
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__ stimulates intestinal Ca and phosphate absorption and bone remodeling
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active vitamin D
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explain the synthesis and regualation fo vitamin D
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UV cause 7-dehydocholesterol (in skin) to produce inactive vitamin D (also intake via food)transported to the liverconverted to 25-OH-vit D (inhibited by incrased Ca and PO4)transported to kindeyconverted to active and paritally active vit D by 1-hydroxylase (inhibited by active vit D and stimulated by decreased Ca and PO4)
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what are the three functions of Vitamen D?
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-stimulates syntehsis of Ca binding protien (calbindin) in intestinal and kidney cells-induces Ca channel at brush bordered apical surface of intestine-induces ATP dependent Ca pump, Na/Ca exchanges in basolateral membrane of intestinal cells |
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what are three smaller affects of vitamin D?
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-stimulates intestinal phosphate and Mg abosrption-causes osteoid formation and increase in bone density-Ca uptake by SR
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the major hormone regualting plasma Ca concentration |
Parathyroid hormone
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where is PTH synthesized?
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cheif cells
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PTH synthesis and release is regulated by __
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plasma ionized Ca
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about __% of Ca is reabsorbed passively at the proximal tubule via a sodium water gradient
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60-70
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__% of ca is reabsorbed at the thick ascending limb
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10%
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where is teh primary PTH regulated site of renal Ca reabsorption? |
the distal convoluted tubule (10%)
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what is the primary PTH regulated site of phosphorus reabsorption in the kindey?
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proximal tubule
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explain the action of PTH |
release of Ca and PO4 from boneincreased secretion of PO4 in kidneyincreased Ca reabosorption from kidneyproduction of active vit D in kidneyVit D causes increased absorptin of intestinal CaOverall: increased plasma Ca, Decreased PO4
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what does calcitonin do?
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decreases plasma CA levels by antagonizing PTH
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what regulates CT synthesis?
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plasma calcium via cAMP, gastrin, and other GI hormones
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normla plasma levels of CT are __
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10-20 pg/ml
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CT acts via its surface receptors by the __ system |
cAMP
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what are the 4 affects of CT? |
inhibits osteoclastic acitivty decreases plasma CA by enhancing Ca depostion in bone decreases plasma phosphate increases urinary phosphate excretion |
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alpha cells in the islets of langerhans produce __ |
glucagon |
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beta cells in the islets of langerhan produce __ |
insulin |
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delta cells in the islet of langerhan produce __ |
somatostain |
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F cells in the islet of langerhan produce __ |
pancreatic polypeptide |
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what is the threshold of isulin? |
50 mg/dL |
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insulin is a __ hormone |
protein |
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what are the steps of the insulin hormone production? |
preproinsulin->proinsulin->insulin |
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explain the mechansism by which insulin can be secreted and synthesized and controlled by GLUCOSE |
-glucose brought into cell via Glut 2 transporter (controlled by insulin) -broken down into glucose-6-phosphate by glucokinase -glucose 6 phosphate converted to pyruvate -NADPH+ from ETC closes K channel and opens Ca channel -Ca causes insulin secretion |
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explain the mechanism by which insulin can be secreted by metabolites |
-amino acids, ketoacids, and fatty acids enter the beta cell -converted to pyruvate -stimulate ETC to create NADPH+ -K channels close, Ca channels open -insulin in secreted in order to lower ketoacid proudction |
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explain how CCK and Ach stimulates insulin secretion |
-CCK and Ach stimulates PLC -produces inositol phosphate (increases Ca) -produces diacylglycerol (increase PKC) -causes insulin secretion |
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explain how somatostatin and epinphrine inhibit insulin secrtion while glucagon and NE stimulte it |
-somatostatin and epinephrine decrease cAMP which decreases PKA and insulin secretion -glucagon and NE stimulate cAMP
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explain the regulation and secretion cycle of insulin |
glucose, AA (after conversion to glucose by gluconeogenesis), FFA, K cause increased insulin, causes uptake, metabolism, and storage of those materials |
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glucose induced regulation of insulin is __ |
biphasic |
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__% of the secreted insulin is extracted by the liver |
50% |
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explain what happens when you eat glucose? |
-insulin and glucose spike -glucose plateaus -insulin decrease -insulin steadily increases until it reaches homeostatic levels |
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D-glucose, prolactin, ketoacids, FFA, K, Ca, glucagon, GI hormones, Vegal activity, beta adrenergic and sulfonylurea drugs all __ insulin secretion |
increase |
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fasting, exercise, somatostatin, alpha adrenergic, and prostaglandin E2 all __ insulin secretion |
decrease |
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why would prolactin increase insulin secretion? |
b/c the mammary glands need energy for metabolism |
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what are 10 actions of insulin? |
Stops:gluconeogensis, glycogenolysis, lipolysis, ketogenesis, proteolysis
Stimulates: glucose uptake in muscle and adipose, glycolysis, glycogen synthesis, protein synthesis, uptake of ions (K and PO4) |
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what are the net effects of insulin on the plasma |
decrease in: glucose, FFA, ketoacids, AA |
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how does glucose reduce blood glucose via glycogen? |
by blocking conversion of glycogen to glucose 6 p |
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what are four minor affects of insulin? |
-stimulates uptake of K, PO4 and Mg -stimulates renal resabsorption of K, PO4 and Na -transport of AA to cytoplasm and inductin of protein synthesis -anabolic effect |
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results from the destruction of beta cells of the Islets. primary cuases are plygenic abnormalieis, autoimmune destructino of beta cells, biral, chemical or radiation damage |
Type 1 diabetes (insulin dependent) |
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what are four results of type 1 diabetes? |
-hyperglycemia (inability of glucose utilization & increased glycogenolysis and gluconeogensis) -hyperlipidemia (due to decreased storage of FFA and TG, increased lipolysis and FFA transport to mitochondria) -ketonemia and ketoacidosis (increased FFA oxidation, production of acetone) -hypokalemia and hypoatremia (increased urine volume and decreased renal reabsorption) |
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a metabolic disorder associated with insulin resistance but with normal to slightly high levels of insulin. primarily caused by genetic and lifestyle factos, storng inheritance, involvement of genes |
type 2 diabetes |
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increased thirst and urination increased hunger loss of appetite fatigue blurred visoin slow healing sores are all sympoms of __ |
type 2 diabetes |
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weight BMI index of >25, increased abdominal fat, sedentary lifestyle, family history, race, aging, prediabets and gestational diabetes are all risk factors for __ |
type 2 diabetse |
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what 3 things does insulin deficiency produce in diabetics? |
decreased cellular glucose uptake, increased protein catabolism, increased liplysis |
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what are three tests for diabetes? |
glycated hemoglobin test fasting blood surgar test oral glucose tolerance test |
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diabetes drug that increases tissue sensitivity to insulin and reduces hepatic glucose production |
metformin-oral |
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diabetes drug that stimulates pancreatic insulin secretion |
glipizide |
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dibetes drug that breaks down intestinal carbohydrates, thus lowering the levels of glucose entering the circulation |
acarbose |
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glucagon is synthesized as __ |
preglucagon |
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__ and __ stimulate glucagon secretion |
hyoplycemia, AA |
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what are the 5 functions of glucagon |
-glucagon acts via its cell surface receptors and cyclic AMP -glucagon is hyperglycemic (antagonizes insulin and induces glycogen breakdown -glucagon stimulates gluconeogensis and inhibits glycolysis -glucagon increases fatty acid oxidation in the liver and increases plasma ketoacids -stimulates lipolysis in adipose tissue |
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what are the net plasma effects of glucagon? |
increased glucose, FFA, ketoacids decreased amino acids |
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how does insulin normally act on cells with glucose? |
-brings glucose in via glut 2 -converts it to glucose 6 P -glucose 1 P (byproduct of glucose breakdwon) synthesized to glycogen -converts glucose 6 P to fructose 6 P -PFK1 converts F6P fructose 1 6 bisP -F16BP converted to PEP -PEP converted to pyruate by pyruvate kinase -enters krebs cycle |
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what are three ways that glucagon increases plasma glucose |
1. glycogen synthesis is reversed -glycogen converted to glucose 1 P by glycogen phosphorylase, converted to glucose 6 P then glucose (glucose 6Ptase)
2. glucagon stimulates PKA -stimulates FBPase2 to reverse glycolysis (inhibits PFK1) -also stimulates PEPCK
3.amino acids in the cell are converted to pyruvate -pyruvate converted to oxaloacetate by pyruvate carboxylase -oxaloacetate converted to PEP by PEPCK -PEP converted to fructose 16 bsiP -Fructose 16BP converted to fructose 6P by FBPase 1 -fructose 6P converted to glucose 6P -glucose 6P converted to glucose by glucose 6Ptase |
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explain glucagons effects on FFA's in a normal and low blood glucose situation |
normal: -glucose in liver converted to acetyl-CoA -Acetyl-CoA converted to malonyl CoA by Acetyl-CoA carboxylase -malonyl CoA inhibits FFA uptake into mitochondria to be oxidized
Low glucose: -glucagon stimulates AC to produce cAMP -PKA is activated -PKA inhibts Acetyl-CoA carboxylase -decrease in malonyll CoA -increase in FFA oxidized in mitocondria and secreted as ketone bodies |
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what is the effect of insulin and glucagon on FFA upake and the release of fat? |
insulin: stimulates synthesis of TG from FFA, inhitbits release of FFA from TG
glucagon: stimulates release of FFA to TG |
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what is the effect of insulin and glucagon on liver glycogen? |
insulin: increases synthesis of glycogen (increases glucose uptake and storage)
glucagon: stimulates glycogenolysis and glucose release |
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what are the effects of insulin and glucagon on liver gluconeogenesis |
insulin: inhibits it (stimulates AA storage as proteins)
glucagon: stimualtes (glucose is synthesized and released) |
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what is the effect of insulin and glucagon on glucose uptake in skeletal muscle? |
insulin: stimulates uptake, storage as glycogen, and use in energy metabolism
glucagon: no receptors, no effect |
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what is the effect of insulin and glucagon on glycogen in skeletal muscle? |
insulin: stimulates and is necessary for protein synthesis
glucagon: no receptors, no effect |
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what are the effects of insulin and glucagon on the hypothalamus? |
insulin: reduces hunger through hypothalamic regualtion
glucagon: no effect |
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pancreatic somatostatin is a __ hormone |
peptide |
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__, __, __, and __ stimulate pancreatic somatostatin release |
glucose, AA, FFA, GI hormones |
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pancreatic somatostatin __ the rate of digestion and absorption of nutrients from the GI tract |
decreases |
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pancreatic somatostain inhibits __ and strongly inhibits __ |
intestinal glucose and TG absorption
insulin and glucagon secretion |
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|
explain the feedback control of pancreatic somatostatin |
stimulated by glucose, AA, FFA, GI hormones and glucagon secretion
inhibited by alpha adrenergic stimulus and insulin
it inhibits release of insulin and glucagon causes decreased glucose and AA influx |
|
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what are the two zones of the adrenal glands? |
outer cortex and inner medulla |
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what are the hormones made in the adrenal cortex? |
glomeruosa: mineralcorticoids: aldosterone, deoxycorticosterone, corticosteron
Fasiculata: glucocorticoids: cortisol |
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|
what hormones are made in the medulla of the adrenal gland? |
reticularis: Androgens |
|
|
explain the synthesis of aldosterone in the glomerulosa |
-LDL cholesterol (blood) is endocytosed into the cell -Steroidogenesis Acute Regulator (StAR) takes cholesterol into the mitochondria -side chain cleavage enzymes convert cholesterol to pregnenolone -3B hydroxy steroid dehydrogenase converted pregnenolone to progesterone -21 hydroxylase converts progesterone to DOC -aldosterone synthase converts DOC to corticosterone -aldosterone synthase converts corticosterone to 18-OH-corticosterone -aldosterone synthase converts 18-OH-corticosterone to aldosterone |
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what 5 compounds in the adrenal medulla are present in the glomerulosa and angiotension II regulated? |
StAR, side chain cleavage enzyme, 3 B hydroxysteroid dehydrogenase, 21 hydroxylase, aldosterone synthase |
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explain the synthesis of cortisol in the fasiculata |
-LDL cholesterol in blood endocytosed to cell -StAR takes cholesterol into mitochondria -side chain cleavage convertes cholesterol to pregenolone -17 a hydroxylase convertes pregnenlone to 17-OH pregnenolone -3 B hydroxy steroid dehydrogenase converts 17-OH pregnenolone to 17-OH progesterone -21 hydroxylase converts 17-OH progesterone to 11-deoxycortisol -11 B hydroxylase converts 11-deoxycortisol to cortisol |
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|
explain the synthesis of androstenedione (presursur of androgen) in the reticularis |
-LDL cholesterol (from blood) endocytosed into cell -StAR takes cholesterol into mitochondria -side chain cleavage enzyme converts cholesterol to pregnenolone
-pregnenolone converted to 17-OH-pregeneolone by 17 A hydroxylase -17-OH pregnenolone is converted to DHEA by CYP17 -becomes androstenedoine
-prenenolone converted to progesterone by 3 B hydroxy steroid dehydrogenase -progesterone converted to 17-OH progesterone by 17 A hydroxylase -17-OH-progesterone converted to androstenedione by CYP17 |
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what enzymes are located in teh fasiculata and regularis and are controlled by ACTH |
17 a hydroxylase, CYP17, 11-B hydroxylase |
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what will happen if 21 hydroxylase is compromised? |
the androgen pathway will be the only one affected and its levels will increase |
|
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production of aldosterone is unique to the __ |
glomerulosa |
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the majority of corticosteroids are bound to __ |
corticosteroid binding globulin |
|
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where is cortisol metabolized? |
liver and kidney |
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what must happen to cortisol for it to be excreted? |
conjugated with glucunonic acid to make it water soluble |
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explain the 4 metabolic effects of cortisol on metabolism |
-causes peripheral insulin resistance except for in the liver -mobilizes AA from muscle for gluconeogenesis -induces gluconeogenetic enzymes to increase blood glucose -utilizes epinephrine and glucagon increase blood glucose |
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what are the 5 protein metabolism effects of cortisol? |
-stimulates catabolism and supresses sythesis except in the liver -increases protein synthesis in liver and elevate plasma binding proteins -decreases AA transport to all tissues except the liver -decreases synthesis of collagen and glycosaminoglycans -stimulates appetite |
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cortisol causes the inhibition of glycosaminoglycans and collagen cuasing thinning of the skin and vascular walls. why don't the vessels burst or why is there not swelling? |
it seals the juntions of the endothelial cells |
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what are the 3 effects of cortisol on fat metabolism? |
-increases lipolysis, decreases conversion of glucose to fatty acids -increases of oxidation of fatty acids -stimulates adipocyte differentiation and fat depostition in face, abdomen, and trunk |
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cortisol maintains contractlity and work output of the__ and __ |
heart, skeletal muscles |
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cortisol __ bone formation by blocking synthesis and functins of vitamin D, and __ intestinal calcium absorption and osteoblast formation |
decreases, inhibits |
|
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cortisol maintains blood volume by decreasing __ |
vascular permeability (seals off epithelial cells to prevent leaking) |
|
|
cortisol __ adrenergic vasoconstriction and __ blood pressure |
increases, maintains |
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|
cortisol __ GFR and water excretion |
increases |
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cortisol stimulates __ to prepare the fetal lungs for postnatal breathing |
surfactant synthesis |
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cortisol acts as a __, suppressing mast cell proliferation, histamine release, antibody production, tissue swelling, and PGF2A production |
immunosuppressant |
|
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an excess of cortisol and a decrease in ACTH would lead to __ |
cushings syndrome (adrenal hyperplasia) |
|
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excess ACTH and cortisol causes by an ectopic tumor that doesn't respond to negative feedback is called __ |
cushings disease (pituitory adenoma) |
|
|
increased ACTH and low cortisol cause __ |
addisons disease (autoimmune destruction of adrenals) |
|
|
what two hormones would you see with addisons disease? |
MSH and endorphins b/c more POMC |
|
|
what is caused by an increase in ACTH and a decrease in cortisol |
21 B-hydroxylase deficiency (inability to produce cortisol and aldosterone)
|
|
|
what are the two main functinos of aldosterone? |
renal Na reabsortion to maintain ECFV
renal K excretion to prevent overload |
|
|
what is the main site of action of aldosterone? |
distal tubules and collecting ducts |
|
|
what does aldosterone bind to? |
type 1 receptors |
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cortisol binds to type 2 receptors on the distal tubules and collecting ducts and if activated will produce an aldosterone effect. what prevents this? |
11 B hydroxylase. it inactivates cortisol around aldosterones receptors so that it wont cause an aldosterone effect |
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aldosterone stimulates __ reabsorption which couples with __ affect to reabsorb water and increase ECFV |
Na, ADH |
|
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aldosterone stimulates secretion of __ and __ |
K, H |
|
|
what are the three tubular affects of aldosterone? |
-increases ion channels at luminal suface -increases Na-K pump -stimulate ATP production |
|
|
what three things stimulate aldosterone and what two things inhibit it? |
stimulate: ACTH, POMC, low plasma Na inhibit: ANH, dopamine |
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what hormone contols the escape phenomenon that prevents an overload of Na and edema in hyperaldosteronism? |
ANH (secreted by atrial myocytes) inhibits Na channels and renin secretion |
|
|
a specialized sympathetic ganglion that synthesizes and release primarly E and a small amount of NE |
adrenal medulla |
|
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what are the cells in teh adrenal medulla called? |
chromaffin cells |
|
|
explaine the synthesis of epinephrine |
-tyrosine converted to DOPA by tyrosine B hydoxylase -DOPA converted to dopamine -dopamine converted to NE -NE converted to E by phenyletholamine N-methyltransferase |
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|
where is epinephrine stored? |
chromaffin cells |
|
|
epinephrine is a __ derived hormone |
amino acid |
|
|
explain the secretion of epinephrine |
-stimulated vai splanchnic nerves -Ach causes Ca influx into cell -granules transported to membrane -exocytosis releases entire content (E, NE, AtP, Bhydroxylase) |
|
|
what is the basal plasma level of epinephrine? |
20-50 pg/ml |
|
|
what is the half life of epinephrine |
2 min |
|
|
how is epinephrine degraded in the kidney and liver? |
degraded into: metanephrine by COMT |
|
|
what two things stimulate epiephrine secretion |
emotional activities and stress mild hypoglycemia (without affecting sympathetic activity) |
|
|
what 5 affects does epinephrine have on teh body? |
-hyperglycemic: increases liver and muscle glycogenolysis to increase glucose output -lactate production in muscle to convert to glucose -inhibits insulin release and glucose uptake by muscle -stimulate glucagon release and gluconeogensis -increases hormone sensative lipase to increse fatty acid production for gluconeogenesis |
|
|
epinephrine acts via __ and __ receptors |
alpha, beta adrenergic |
|
|
what symptoms occur from hypersecretion of epinephrine |
-tachycardia, sweating, anxiety, vasoconstirction, chest pain, increased BP |
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|
the vas deferens function is __, the seminal vesicle function is __, te prostate gland function is __, __, and __, th epididymis function is __ and __, and the testis function is __ and __ |
sperm carrier, seminal secretion, acid, phosphatase, proteases, prostate-specific antigen, sperm maturation and storage, sperm and steroid hormone production |
|
|
semen is composed of __ |
sperm, secretions of the seminal vesicles and prostate |
|
|
what is the male genontype? |
46 XY |
|
|
explain male puberty (6) |
begins at 10-11
ends 15-17
Activation of GnRH, FSH levels rise first followed by LH
increase in testicular volume b/c of growth of seminiferous tubules
Leydig cells appear and secrete testosterone
testosterone rises rapidly over 2 year period and induces pubic hair, penile growth, sperm production, linear growth |
|
|
why does linear growth cease during male puberty |
ossification of epiphyseal cartilage |
|
|
what stimulates GnRH secetion during puberty? |
outside information input |
|
|
__% of the testis are comprised of the seminiferous tubule
the wall contains __ and __ and is surroudned by a basement membrane and a layer of __ |
80, germ cells, sertoili cells, smooth muscle cells |
|
|
sperm production occurs in the __ |
seminiferous tubules |
|
|
what is contained in the intertubular space __ |
leydig cells |
|
|
leydig cells are __ and produce __ |
LH sensitive, androgen |
|
|
what is the peak production average of sperm per day? |
100-200 million |
|
|
spermatogenesis occurs through __ stages in a __ fashion, and the cycle length is __ days |
6, cyclic, 65-70 |
|
|
what are the 6 stages of spermatogenesis |
primary speratogonium, secondary spermatogonium, primary spermatocyte, secondary spermatocyte, spermatid, spermatozoon |
|
|
spermatogenesis occurs in between two adjacent __ |
sertoli cells |
|
|
explain the blood testis barrier |
tight junctions formed by two sertoili cells which divide the tubular wall into a basal and adlumina compartments |
|
|
explain how spermatogenesis happens (4) |
spermatogenesis causes germ cells to move from the basal to the luminal side
spermatids attach to sertoli cells, penetrate into the cytoplasm and undergo metamorphosis called spermiogenesis to form spermatozoa
during spermiogenesis cytoplasm shirnks chromosome condnese, arcosome sac appears on the apical side and flagellum develops
spermatozoa are transported into the epididymis by the process called spermiation |
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|
explain the divisional steps sperm cells go through during sperm development (6) |
primordial germ cells--mitosis
spermatogonial stem cell--mitosis
spermatogonium (A divides, B goes back to replenish)--mitosis
primary spermatocyte--meiosis I
secondary speratocyte--meiosis II
Spermatids |
|
|
in the regulation of spermatogenesis, __ maintains sertoli cell functions and is essential for spermatogensis while __ is vital for the completion of meiosis of the primary spermatocytes |
FSH, testosterone |
|
|
the main testicular steroid is __; which is synthesized in teh __ cells from __ and regulated by __ |
testosterone, leydig cells, cholesterol, LH |
|
|
other than testosterone, leydig cells also synthesize __ and __ |
E2 and growth factors |
|
|
testoterone is reduced in target tissue to __, a potent androgen |
5a-DHT |
|
|
most of the testosterone and DHT in the plasma are bound to __ |
sex teroid binding globluln and aldbumin |
|
|
leydig cells response to LH declines at the age of __ and plasma testosterone levels gradually declines |
70-80 |
|
|
what are the pubertal affects of testosterone? |
seminal vesicle and beard growth
increased VLDL and LDL, decreased HDL
RBC, muscle mass and upper body fat increase
larynx muscle growth |
|
|
what are the intrauterine differentiation affection of testosterone? |
male imprint type, epidiymal, vas deferens, and seminal vesicle differentiation |
|
|
what are the pubertal developmental affects of DHT? |
sebum formation, development of the prostate gland, penile development
sperm production |
|
|
what are the intrauterine differentiation affects of DHT? |
penis, scrotum, urethra, and prostate differntiation
male type imprint |
|
|
what are the three steps of oogenesis? |
in utero: germ cells-->mitosis-->oogonia-->meiosis up to 1st meiotic stage (now primary oocyte)
ovulation: complete first meiotic divison (now secondary oocyte)
fertilization: undergo 2nd meiotic division |
|
|
what are the germ cell numbers for females before birth, after birth, and by puberty? |
before: 6-7 million
birth: 2 million
puberty: 400,000 |
|
|
what three things does an ovary contain? |
follicle, stroma, corpus luteum |
|
|
cells that maintain a viable oocyte; provide essential hormonal support for reproduction |
follicles |
|
|
intersitial cells and other supporting cells in teh ovary |
stroma |
|
|
formed from the follicle after ovulation, produces progesterone for pregnancy onset and maintenance |
corpus luteum |
|
|
what would be the only cells you should see in a female ovary during early puberty? |
primordial, primary and preantral follicles |
|
|
what are the three main steroid hormones that the ovary produces? |
progesterone (from thecal and luteal cells)
estrogens (E1 and E2) (from granulosa cells)
androgens (from thecal cells) |
|
|
explain the production of progesterone and estrogen |
-LH binds to a receptor on the theca cells which stimulates cAMP to activate side chain cleavage enzymes
-side chain cleavage enzymes convert cholesterol to progesterone
-progesterone is converted to androgen by 17 alpha hydroxylase
-androgen moves into the granulosa cells
-FSH binds to a receptor, generates cAMP activates aromatase
-aromatase converts androgen to E1 and E2 |
|
|
name the functions of estradiol for the ociduct (2), uterus (2), cervix and vagina (3), breast (4), bone (5), larynx (1), liver (3), and fat cells (2) |
oviduct: forms and contracts cilia, muscular contraction
uterus: increase endometrial proliferation, myometrial growth and contractility
cervix and vagina: epithelial proliferation, glycogen deposition, water cervical mucous
breast: proliferation of ductal epithelium, ductal growth, lobulo-alveolus growth, fat deposition
bone: osteoblastic acitvity, Ca deposition, linear growth, maturation of epiphyseal cartilage, increase in pelvic diameter
larynx: long and unchanged vocal cord
liver: thyroid and steroid binding globulins, decreased LDL and VLDL, increased HDL
fat: lipgenesis and fat deposition in thigh and hip |
|
|
what are the functions of progesterone on the oviduct (2), uterus (3), breast (2)and cervix and vagina (3) |
oviduct: increased secretion, decreased muscular contraction
uterus: increased endometrial differentiation, glycogen and glycoprotein synthesis and secretion
decreased myometrial growth and contractility
breast: increased development of lobulo-alveolus, retention of fluid in subcutaneous tissue
cervix and vagina: increased epithelia differntiation, thick cervical mucous, decreased epthelial proliferation |
|
|
why is ther glycogen depostion in the cervical mucous? |
to attract bacteria to secrete lactic acid and create a hostile environment |
|
|
what hormone cuases bloating during ovulation? |
progesterone |
|
|
what does thick cervical mucous do? |
prevents sperm from entering into the mucous |
|
|
the transition from a sexually immature to mature state |
puberty |
|
|
what are the three steps in female puberty? |
adrenarche (maturation of adrenal glands
activation of H-P-O axis (most important)
gonadarche (maturation of ovaries) |
|
|
what is the main cause of the onset of female pubertY? |
the maturation of GnRH neurons which function as a unit |
|
|
female puberty onset depends on what three things? |
nutrition, health, and environment |
|
|
what happens during adrenarche? |
synthesis of adrenal androgens at the onset of puberty, development of pubic and axillary hair |
|
|
explain the activation of the hyopthalamo-pituitary ovarian axis (HPO) |
intitially GnRH neurons fire independently
as puberty begins firing increases and causes FSH release and stimulation of ovaries to develop and produce estrogen
estrogen negatively feeds back on GnRH and FSH which kills the follicles.
GnRH then continues to swell which leads to larger estrogen levels and increased follicular development |
|
|
what is the hallmark of puberty onset in females? |
pulsitile GnRH secretion |
|
|
explain the maturation of the HPO axis and the first ovulation |
-high estrogens during the first few cycles cause synchronization of GnRH neurons
-large amount of GnRH is released
-causes the preovulatory surge
--first ovulation occurs (menarche) |
|
|
what are three body growth changes that occur during female puberty? |
fat deposition (hips, thighs, mons pubic)
increased bone length (Ca and PO4 deposition)
cessation of body growth (ossification of epihyseal cartilage |
|
|
what changes in breast development occur during female puberty? |
estogen induced proliferation of mammary epithelium and fat deposition |
|
|
what induces pubic hair develpoment in females during puberty? |
androgen |
|
|
what are the two phases of the menstrual cycle? |
follicular, luteal |
|
|
how long is the menstrual cycle? |
28 days |
|
|
when does ovulation occur during the mestrual cycle? |
14 days in |
|
|
what occurs in the follicular phase of the menstrual cycle? |
follicular development |
|
|
what occurs during the luteal phase of the menstrual cycle? |
completion of the cycle |
|
|
__ regulates granulosa cell proliferation and activities; __ regulates thecal proliferation and activities |
FSH, LH |
|
|
explain folliculogenesis and the selection of the dominant follicle |
at the end of a cycle and teh beginning of a new one FSH is secreted which causes the follicle to grow and produce estrogen
estrogen negatively feeds back and inhibits FSH release.
the dominant follicle has more receptors hormones so even at the lowered FSH levels it still grows.
it eventually produces a large amount of estrogen which causes a large "ovulatory surge" of LH causing a large amount of progesterone needed for pregnancy |
|
|
expalin the 7 steps of ovulation |
LH, progesterone, activation of proteases, weakened follicle wall, disintegration of stigma, follicle rupture, expulsion of oocyte |
|
|
following ovulation, both granulosa and theca cells undergo significant hypertrophy to form __. a process called __ |
lutein cells; luteinization |
|
|
what are the main hormones the corpus luteum? |
progesterone and inhibin A |
|
|
what does the corpus luteum use progesterone and inhibin for? |
progesterone: uterine preparation for pregnancy
inhibin: inhibition of FSH and LH secretion |
|
|
what three changes occur during the follicular phase of ovulation? |
endometrial cells proliferate and vaginal wall thickens
endocervical glands secrete watery mucus
increased movement of oviducatl cilia |
|
|
what three changes occur during the luteal phase of ovulation? |
endometrial proliferation ceases
endometrial cells synthesize glycogen, glycoprotein, and mucus
by midluteal phase endometrial glands secrete copious amounts of mucus containing nutrients to support the embryo |
|
|
the separation and expulsion of the top layer of the endometrium |
menstruation |
|
|
what is the usual blood loss for menstruation? |
25-60 ml |
|
|
how does menstruation occur? |
absence of pregnancy causes corpus luteum to die within 7-8 weeks, progesterone levels fall sharply
arterioles contrsict and blood vessels leak causing blood accumulation between enometrial layers.
top layer seperates
uterus contracts resulting in teh expulsion of blood and tissue fragments |
|
|
when menstrual cycles stop with gradual thinning of the uterine endometrium and vaginal epithelium; endocervical secretion stops and breast mass unergoes reduction |
menopause |
|
|
what is the average age of menopause? |
50 years |
|
|
what causes menopause? |
exhaustion of follicle pool and cessation of folliculogenesis
lack of estradiol and progesterone |
|
|
what are three changes in reproductive organs during menopause? |
blood FSH and LH levels increase (no feedback)
endometrial and vaginal cyclicity become irregular and finally stop
uterine and vaginal epithelia involute and endocervical secretion gradually stop (thinner and dryer) |
|
|
what are three physical changes that occur with menopause? |
vasomotor instability (lack of estradiol) causes hot flash
loss of bone density
increased LDL cholesterol and depostion in vasculation (unopposed androgen) |
|
|
the process by which the sperm and egg nuclei fuse to form a zygote |
fertilization |
|
|
only __ speratozoa finally reach the ampullary isthmic junction of teh oviduct |
50-200 |
|
|
the process in which the sperm is made mobile and able to fertilize the egg |
capacitation |
|
|
how do different parts of teh oviduct differ with relation to smooth muscle? |
the more distal segments have very little, as you go proximal smooth muscle increases. needs to be timed with uterus deveopment |
|
|
a process by which the blastocyst attaches itself on the endometrial surface and invades teh uterine decidua to form the fetus |
implantation |
|
|
the process of implantation takes __ days. during this process, uterine endometriuma t the stie of implantation differentiates into __ |
6-7, decidual cells |
|
|
__ days after fertilization, the trophectoderm differentiates into __ and __ |
6-7, syncytiotrophoblast, cytotrophoblast |
|
|
the syncyitiotrophoblast cells secrete __ |
hCG |
|
|
what does hCG do? |
stimulates corpus lutem for progestrone secretion until placenta can take over |
|
|
a unique organ that supplies nutrients and O2 to the fetus whle removing metabolic by products and CO2 from the fetus. also provides endocrine support crucial for maintenance of pregnancy and fetal development |
placenta |
|
|
what are the two parts of teh placenta? |
chorionic villi and unterine endometrium |
|
|
the __ layer of the placenta separates maternal blood from fetal blood |
syncytiotropblast |
|
|
what 6 hormones does the syncytiotrophoblast secrete? |
hCG, hPL, hCS, progesterone, estrogens, prostaglandins |
|
|
hCG is similar to LH but has a __ |
longer half life |
|
|
why do hCG levels increase during the 1st trimester? |
growth of syncytial cell layer of placenta |
|
|
what is the most important diagnostic tool used to monitor the onset and progression of pregnancy? |
urinary hCG B |
|
|
what is the luteal-placental shift? |
by the 7th week the placenat takes over hormonal functions for the corpus luteum |
|
|
what does a steady increase in hCS from the placenta during pregnancy do? |
cuase peripheral insulin resistance in that area to free up nutrients for the baby |
|
|
explain the feto-placental unit and the synthesis of estrogen |
the placenta and corpus luteum secrete progesterone which is transfered to the feta adrenal system
progesterone is converted to DHEA by 17 A hydroxlyase
the fetal liver converts DHEA to 16a-DHEAS
DHEA from the fetal andrenal glands and 16 A DHEAS are converted to E1/E2 (by aromatase) and E3 respectively |
|
|
the placental membrane is __ to glucose, O2, AA, FFA, Na, K, Cl, ketone bodies, vitamins, many viruses, and lipid soluble narcotics.
it is __ to many immunoglobulins and many chemicals that are embryo toxic |
permeable, impereable |
|
|
what are the two goals of maternal adjustments during gestation? |
provide adequate nutrtion to the fetus
maintain maternal physiology with biological increases |
|
|
what 4 cardiac changes occur maternally during gestation? |
30% increase in plasma volume, 20-30% increase in RBC mass
increase in renin, aldosterone, AnGII (increase in ECFV)
secretion of placental prostacyclin (maintains normal blood pressure by vasdilation)
by 10th week CO increases 40% |
|
|
how does respiration change maternally during gestation? |
increase rate of resipration (stimulated by progesterone) |
|
|
what is the average weight gain during pregnancy and how much of it is fetal or placental |
24 LB, 50% |
|
|
what is the average daily extra calorie intake and protein intake? |
250-300, 30g/day |
|
|
how does maternal metabolism change in the first half of gestation and in the second? |
1st: glycogen, fat storage increase (anabolic state)
2nd: maternal insulin resistance allows free flow of nutrients to fetus (accelerated starvation) |
|
|
by weeks 24-28 the __ alveolar cells syntehsize and secrete __ in order to allow for sucessful breathing after birth |
type II, surfactant |
|
|
how does the baby's respiration change during birth? |
birth causes stimulation of respiratory centers
diaphragm descends and creates -40 cm H20 pressure which opens alveoli and 40 cc air flows in (onset of breathing)
presence of air prevents alveolar collapse |
|
|
a process by which the uterus expels the mature fetus and placenta and reverts to pregravid size |
parturition |
|
|
what are the three phases of parturition? |
1: initiation of labor
2: delivery of fetus and placenta
3: unterine contractions revert to pregravid size |
|
|
what three factors are responsible for parturtion? |
1: estradiol causes secretion of PGE2 in placenta and decidua
2: PGE2 causes collagen of cervix to degrade collagen and cause stretch
3: cervix stretch casuses secretion of oxytocin and ststenance of myometrial contractions
|
|
|
what causes labor pain? |
pain sensory mechanisms in smooth muscle |
|
|
what is the average blood loss during deliverty? |
350 ml |
|
|
the process by which milk in synthesized and secreted by the mammary glands |
lactation |
|
|
milk is __, not secreted |
ejected |
|
|
what what three hormones that induce ductal development? |
estradiol, GH, prolactin |
|
|
what hormone induces oxytocin receptors in alveolar and ductal smooth muscle cells |
estradiol |
|
|
what 8 hormones induce lobuloalveolar development? |
progesterone, estradiol, prolactin, GH, insuliln, IGF1, thyroxine, and cortisol |
|
|
what two hormones induce milk synthesis |
prolactin, cortisol |
|
|
why does milk syntehsis not occur during gestation? |
estradiol inhibits prolactin binding to its receptors
progesteone inhibits cortisol induced milk protein syntehsis |
|
|
what three ways does progesterone interfere with prolactins action at teh prolactin receptor levels? |
inhibits up regulation of prolactin receptor, reduces estrogen binding, competes for cortisol binding |
|
|
what happens to estradiol and progesterone levels after delivery |
fall very low, inhibition of prolactin is withdrawn |
|
|
explain teh milk let down reflex |
suckling stimulates oxytocin release to nipples causing contractions which make milk flow through the duct and nipple |
|
|
the first milk is called __ that contains a high amount of protein but low amounts ofcarbohydrate and regualr amount of fat |
colostrum |
