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97 Cards in this Set
- Front
- Back
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anterior pituitary develops from an
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upward outpouching of ectodermal cells from the roof of the oral cavity called rathke's pouch
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posterior pituitary develops from
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downward growth of ectoderm from the brain
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pituitary is separated from the oral cavity by
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sphenoid bone, sella turcica
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anterior pituitary cell types
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corticotropes
somatotropes lactotropes thyrotropes gonadotropes |
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anterior pituitary blood supply
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does not receive a direct supply of arterial blood
primary capillary plexus and secondary capillary plexus |
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posterior pituitary blood supply
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inferior hypophyseal artery
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posterior pituitary hormones secreted
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ADH
oxytocin |
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peptides of ADH and oxytocin are synthesized in _____ and ____ of the _______
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supraoptic and paraventricular nuclei
hypothalamus |
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the ratio of neurophysin and hormone is
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1:1
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Acidophils contain ____ hormones
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PRL and GH
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Basophils contain ____ hormones
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FSH, LH, TSH, ATCH
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TRH
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stimulates TSH and prolactin release from anterior
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GRH
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stimulates LH and FSH release from anterior pit.
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CRH
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stimulates ACTH release
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somatostatin
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inhibits TSH and GH release
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regulators of ADH
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osmotic and volume stimuli
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osmolality changes detected by
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putative hypothalamic osmoreceptor system
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osmoreceptor system located in
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supraoptic and paraventricular nuclei
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receptors for volume control are located in
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atria, baroreceptors of the carotid sinus, possibly elsewhere
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somatostatin
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inhibits TSH and GH release
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regulators of ADH
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osmotic and volume stimuli
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osmolality changes detected by
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putative hypothalamic osmoreceptor system
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osmoreceptor system located in
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supraoptic and paraventricular nuclei
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receptors for volume control are located in
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atria, baroreceptors of the carotid sinus, possibly elsewhere
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most potent stimulator of oxytocin is
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suckling
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____ also stimulates oxytocin
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cervical stretch
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secondary actions of ADH
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stimulation of ATCH secretion from anterior pituitary and vasoconstriction
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oxytocin's actions
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stimulation of the concentration of myoepithelial cells surrounding alveoli of mammary glands
stimulation of uterine myometrial contractility |
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oxytocin is potentiated by
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estrogens
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__, ___, and ___ hormones all have
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the same alpha subunit but different beta subunits
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PROP1 mutation
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lose 4 hormones
keep ACTH panhypopituitarism |
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PIT1 mutation
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lose somato/lactotrophs/ thyrotropes
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HESX1 mutation
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lose all 5 cell types
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Infarct of Ant. pituitary causes
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cell death and loss of function
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GH in the liver generates production of
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somatomedins (IGF)
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Pathway that GH generates IGF
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JAK/STAT which enters nucleus and stimulates production of IGF-1
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IGF receptor has ____ activity
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TK
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half life of IGF vs. GH
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IGF = 20 hrs.
GH = 20 mins |
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second messenger of GHRH
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Gs
cAMP PKA |
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GH primary function
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> free glucose in body
synthesize protein |
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GH functions
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decrease glucose uptake into cells
increases lypolysis increases protein synthesis in muscle increases production of IGF |
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IGF acts to increase 4 things__
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protein synthesis in chondrocytes
linear growth protein synthesis in muscle protein synthsis in prgans |
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which action predominates GHRH or somatostatin
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somatostatin
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IGF-1 inhibits
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GH secretion of IGF-1
GHRH secretion |
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IGF-1 activates
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SRIF
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GH inhibits
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its own secretion
GHRH |
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GH activates
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SRIF
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prolactin's 2 main functions
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lactogenesis- stimulation of milk production
breast development (along with estrogen) |
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prolactin is structurally homologous to
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GH
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predominate regulation of prolactin
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dopamine- inhibitory
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TRH increases____ production
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prolactin
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prolactin stimualtes hypothalamus to
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release dopamine
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prolactin inhibits_____ by decreasing________
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ovulation/sprematogenesis
decreasing synthesis/release of GnRH |
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deficiency in prolactin is characterized by
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failure to lactate
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main site of prolactin self-regulation
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median eminence
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how does estrogen regulate prl
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activates prl synthesis and blocks dopamine
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three main stmiulus for prolactin secretion
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suckling
sleep stress |
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ADH acts on what cells via ___ receptor
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principal cells of distal tubule and collecting duct
V2 receptor - AC-cAMP mechanism |
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ADH secondarily acts on what cells via___ receptor
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alpha-1 adrenergic receptors
V1- Ip3/Ca constricts vascular smooth muscle |
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ADH also stimulates
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ACTH secretion
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Oxytocin functions to
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eject milk from breast when stimulated by contracting myoepithelial cells in breast
also contract uterus to induce labor and reduce postpartum bleeding |
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stimulation of oxytocin release
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suckling
dilation of cervix/orgasm |
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action of oxytocin is potentiated by
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estrogen
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thyroid hormones depend on
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Iodine
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the I- pump is found in
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thyroid follicular cells
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I- pump pumps I into
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thyroid follicular cells
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if there is too much I- in cells, the
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Pump will be inhibited
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I2 is added to tyrosin which is located on ______ using ___ enzyme to make either ___ or ___ in what junction
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thyroglobulin
located on ribo of follicular cells using peroxidase enzyme MIT or DIT lumen/follicular cell |
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MIT + DIT =
DIT + DIT = |
T3
T4 |
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most abundant secreted thyroxine =
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T4
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T4 can be converted to __- by ___
T4 can be converted to ___ by ___ |
T3- 5'deiodinase
rT3- 5-deiodinase |
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T3/T4 mostly bound to___ made in the ___
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TBG which are made in the liver
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TBG levels increase in
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pregnancy
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T3 can bind ____ which _____
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TRH-R
decreases synthesis/secretion of tSH |
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TH function in bone
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increases formation (along with GH) and maturation
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TH function in CNS
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critical for CNS development
axon development myelination |
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TH function in ANS
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up-regulation of B1- adrenergic receptors in heart
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TH function in BMR
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increases synthesis of Na,K-ATPase
increases oxygen consumption related to Na, K-ATPase |
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cardio/respiratory effects of TH
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need more O2 delivery to tissues
increases HR/SV increases ventilation rate |
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TH effects on metabolism
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increased to meet demant from increased oxygen consumption
increased glucose utilization, glycogenolysis, gluconeogenesis, glucose oxidation, lipolysis, chol. synthesis, chol. conversion to bile, protein synthesis and degredation |
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TH effects on GI
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increases GI motility
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zona glomerulosa secretes
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aldosterone
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zona fasiculata secretes
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glucocorticoids (cortisol)
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zona reticularis secretes
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androgens
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21 carbon steroid
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aldosterone
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18 c steroid
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estrogen
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StAR protein
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transports cholesterol into mito
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PBR =
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steroid channel activated by StAR
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glucocorticoid secretion stimulated by
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CRH, ATCH,
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CRH binds___ and synthesizes__ which leads to ___ secretion
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corticotrophs
synthesizes POMC ACTH |
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ACTH action
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increases # of LDL receptors
simtulates cholesterol desmolase increases steroid hormone synthesis upregulates its own receptor hypertrophy of adrenal cortex |
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cortisol inhibits
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CRH and ACTH
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glucocorticoid overall action on metabolism
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increases gluconeogenesis
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glucocorticoids maintain____ by____
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metabolic machinery
PEPCK glucose-6-phosphatase lipolytic agents |
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glucocorticoids suppress inflammation and immune system by
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inhibiting prostaglandin/leuko synthesis
inhibits production of IL-2 and proliferation of T-lymphocytes inhibits histamine response |
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circulation effects of glucorticoids
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upregulate A1 receptors
increase NE effect of vasoconstriction increase bloodpressure |
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mineralcorticoid effect of glucocorticoids
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cortisol at excessive amounts can bind mineralcortioid action
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