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72 terms

SGU Physiology - Endocrine

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McCune-Albright Syndrome
clinical: GNAS mut on 20q -> mut Gsalpha + oths -> var hyperfx endocrine glands, cafe-au-lait spots, polyostotic fibrous dysplasia
humoral
hormone release: []ecf
neural
hormone release: nn innerv gland
hormonal
hormone release: release of oth hormones
GH (growth hormone)
hormone: stim by GHRH, inhib by SS (both from somatotrophs of HypThal), JAK2 -> STAT -> Tyr Kinase, involves inc IGFs (somatomedins) -> inc mm AA uptake, lipolysis, [Glc]bl
IGFs (insulin-like growth factors)
hormone: works w/ GH to inc cartilage, bone growth, prot synth + cell growth, can be used to indirectly meas GH levels
Prolactin
hormone: INHIB by dopa from HypThal (poss stim by E2 -> TRH + PRF) -> made by lacto(mammo)trophs -> JAK2 -> STAT -> TyrKinase -> dev breasts + make milk
Oxytocin
hormone: nursing or cervical P -> hypthal -> pos. pit -> inc Ca2+ -> Gq -> smooth mm contract
parafollicular cells
thyroid cells: secrete calcitonin
follicular cells
thryoid cells: secrete T3 (tri-iodothyronine) and T4 (thyroxine)
TRH (thyroid releasing hormone)
hormone: PVN of Hypthal synth -> Ant. Pit. Gq on Thyrotrophes -> inc TSH, pulsatile circadian rel, neg feedback, t1/2 = 5min
TPO (ThyroPerOxidase)
enzyme: conv Iodine -> Iodide to combo w/ TG (ThyroGlobulin)
NIS
pumps iodine in to cell against [] grad. by coupling w/ Na+
T3 (triiodothyronine)
hormone: the more active thyroid hormone, but makes up 10% of ecf [], can be made from oth thyroid hormone via deiodinase
Graves Disease
clinical: TSH-R ABs -> high T3, T4 but low TSH (vs. thyrotrophoma = high T3, T4 and high TSH)
Aldosterone
hormone: stim by AII or K+ (min ACTH from corticotrophs) -> Z. glomerulosa -> inc Na+ reabs + K+ secr in DCT + CD Principal cells, 50% bound to prots, 15 min t1/2
CRH
hormone: synth in Ant PVN, stored imn median eminence -> corticotrophs -> Gs -> synth POMC, pulsatile diurnal rel
ACTH
hormone: synth from POMC -> Melaocortin-2 Gs Rs on adrenal gland -> + P prots and activate StAR (but only in Z. fasiculata + reticularis)
StAR (Sterioid Acute Regulatory protein)
mitoch memb Chol chan so Chol can be converted to Pregnenolone in mitoch, activated by ACTH in Z. fasiculata + reticularis, and by AII or K+ in Z. glomerulosa
CYP11A
enzyme: converts Chol -> Pregnenolone, aka Chol Side-Chain Cleavage Enzyme)
CYP17A (17-alpha-hydroxylase)
enzyme: converts Pregnenolone to DHEA and Progesterone to Androstenedione
3-B-HSD II (3-beta-Hydroxysteroid deHydrogenase)
enzyme: converts Pregnenolone to Progesterone and 17-alpha-pregnenolone to 17-alpha-progeterone
CYP21A2 (21-hydroxylase)
enzyme: converts Progesterone to to 11-Deoxycorticosterone and 17a-OH Progesterone to 11-Deoxycortisol, defic = dec Ald + cortisol -> Virilizing Congenital Hyperplasia
CYP11B1 (11-beta-hydroxylase)
enzyme: converts 11-Deoxycorticosterone to Corticosterone and 11-Deoxycortisol to Cortisol
CYP11B2 (Aldosterone synthase)
enzyme: converts Corticosterone to Aldossterone
HSD11B
enzyme: converts Cortisol to Cortisone (inactive metabolite) in kidneys, inhib by licorice => can result in mineralocorticoid excess
Conn Syndrome
clinical: Z. glomerulosa tumor (low renin)or inc renin secrete (HIGH renin)-> inc Ald -> hypertension, hypervolemia, hypokalemia, slight hypernatremia
Addison's disease
clinical|: autoimmune adrenal or granuloma-> dec adrenal hormones -> polyuria, dehydration, hypotension, hyperkalemia, hyponatremia, weak, stressed, anorexia, dark skin
mitochondria
location of CYP11A (Chol-Side-chain Cleavage Enzyme) + 11-beta-HSD
smooth ER (SER)
location of steroidogensis enzymes that are NOT CYP11A (Chol-Side-chain Cleavage Enzyme) + 11-beta-HSD
glucocorticoids
hormone: class of hormones from Z. fasiculata that includes Cortisol, norm bound to plasma prots like CBG (Cortisol Binding Globulin = Transcortin), 8% bound to albumin, 5% free -> conj by liver -> excr by kidney
androgens
hormone: sex hormones from Z. reticularis, norm bound to albumin -> degraded or metabolized in to more active products, NO neg feedback on ACTH or CRH => reg by glucocorticoids
cortisol
hormone: primary glucocorticoid, inc Glc production by liver (hypOglycemia) or inc Glc storage (hypERglycemia), inc proteolysis, lipolysis, [Glc]bl (by opposing Insulin on most tissues), stim surfactant, lactation, inc contractility, inhib immune + inflamm response (inhib PLA-2), inc appeptite, neg Ca2+ bal
Cushing's Syndrome
clincal: var probs assoc w/ inc Cortisol (ACTH-indy), could be due to overuse of corticosteroids or small oat cell carcinoma
Cushing's Disease
clinical: Ant Pit Tumor -> hyper ACTH -> hyper cortisol (ACTH-dep)
Acute Adrenal Insufficiency
clinical: sudden withdrawal corticosteroids -> hypovolemic shock, postural hypO tension
VMAT (vesicular monoamine transporter)
transports dopa and Epi in to secretory vesicles in chromaffin cells
uptake-1
catech breakdown: in synaptic clefts/nerve terms -> MAO -> VMAT
uptake-2
catech breakdown: in target cells -> MAO + COMT
pheochromocytoma
clinical: chromaffin tumor -> inc NE rel (+ Epi, Dopa) -> hypertension, headache, chest pains, anxiety, perspiration, high Bp, hyperglycemia, glucosuria
C-peptide
component of endogenous insulin that is fully excr => good marker for insulin
GLUT2
insulin-independent Glc transporter
sulfonureas
drug: DM2 pt -> block K-ATP chan -> inc intracell K+ -> depol -> Ca2+ influx -> make insulin
GLUT4
insulin-sensitive (dep) Glc transporter
amino acids
major stimulus for alpha -> glucagon release
muscle
organ/system that glucagon has NO effect on but insulin does
osteoblasts
increase bone production (remove free ionized Ca2+ from bl)
osteoclasts
inc Ca2+ resorption in bone
osteocytes
involved in Ca2+ turnover in bone (bring Ca2+ back to bl)
chief cells
cells that synth PTH
PTH (parathyroid hormone)
hormone: secreted by chief cells, stored in secr granules in response to dec ionized Ca2 via weird reverse Gq mech (since it's not INC but DEC Ca2+ that stim rel) -> Gaq + Gas R on osteoblast -> inc M-CSF, RANK, IL-6 (stim osteoclasts) -> inc Ca2+ resorption, also helps resorb the 10% of Ca2+ that reaches the DCT, inc 1-a-hydroxylase (calcitriol synth)
phosphate
ion: PTH -> released from bone and dec resorb from kidneys => excr VS VitD -> inc GI + kidney absorption -> inc
Calcitriol (Vitamin D)
vitamin: 7-dehydroCho in skin -> Cholecalciferol from diet --25-hydroxylase (liver)--> 25-OH-Cholecalciferol --1-hydroxylase--> 1,25-dihydrocholecalciferol, stim by PTH (low ionized Ca2+) in PCT of kidney -> inc Ca2+ + PO4- absorb in gut, req for norm bone form, inc Ca2+ resorb in DCT
LH
hormone: stim by high freq GnRH rel, Gs on Leydigs or Theca cells-> conv Pregnenolone -> E2
GNRH (GRH)
hormone: 10aa peptide synth in arcuate nu -> stored in vesicles -> portal -> ant pit gonadotrophs -> Gq, pulsatile release, 2-4min t1/2
FSH
hormone: stim by low freq GnRH -> Gs on Sertolis or Granulosa cells-> inc Inhibin, Aromatase, ABP, GFs, activin, follistatin
ABP (androgen binding protein)
stim by FSH -> maint high androgen levels in tubles, carries testoterone to epididymis
epidymus
where 10% of the ejaculate (just sperm) is stored
ductus deferens
where 60% of the ejaculate is formed: Frc, PGs (inc contract smooth mm), CFs
prostate gland
where 30% of ejaculate is formed, + alkaline (neut acidic vagina), semen clotters (keep semen in vagina), unclotters (ex: fibrinolysin to swim to ova)
bulbourethral gland
secretes mucus to aid in lubrication during sex
theca cells
have LH Rs (Gas)-> Chol --CYP11A--> Progesterone --CYP17--> androstenedione which can be taken up by Granulosa cells to be converted to E2
Granulosa cells
have FSH Rs (Gas) -> converte androstenedione from theca cells to E2 (aromatase), also have LH Rs during Luteal phase => can directly make their own Progesterone, secrete Inhibin,
Progesterone
hormone: made from Chol via CYP11A, PRE-ovul = LH surge, inhib E2, OVUL = collagenase + PGs -> rupture, uterine excitability, alveoli cells, endometrium secr, PREG = uterus endometrial, maint preg, cervical mucus plug, breast dev
E2 (estradiol, estrogen)
hormone: product of T -> aromatase -> PUBERTY = inc reprod organs, breast dev, epiphyseal fusion, change uterine cells, protect vaginal epith, POST-puberty = inc cil cells in oviduct, in protsynth, subcut. fat deposit, ovarian fx, PREG = prep for parturition, dev breast, inhib make milk
hCG (human Chorionic Gonadotropin)
hormone: synth by embryo before implantation and syncytiotrophoblasts after implantation, sim to LH but perserves Corpus Luteum (=> inc E2, P)
hCS (human Chorionic Somatomammotropin, hPL)
hormone: aka human Placental Lactogen, HCS1,2 Rs, sim to GH, inc breast, dec insulin sensitivity, inc Glc for fetus
DHEA-S
hormone: used by placenta to produce estrogens, synth mostly in fetal cortex
pre-eclampsia
clinical: hypertensive pregnancy after 20th week -> headache, confusion, ab pain, fetal growth retardation
oxytocin
hormone: 9AA stored in pos pit -> imp for parturition and lactation, Gq -> maint contract, or post-birth -> suckling mechRs in nipple -> hypthal -> PosPit. -> rel -> milk let-down reflex
dystocia
clinical: abnorm or diff labor, norm due to cephalopelvic disprorportion or labor anesth
Prolactin
hormone: stim by suckling mechanoRs on nipple -> hyThal -> inc PRF/dec dopa -> Ant Pit -> secrete, dec GnRH (=> ammenorrhea, dec E2 + Prog which inhib lactogenesis), lactogenesis