Question | Answer |
Autocrine hormones act on the SAME/OTHER cells that produce them. | same |
Paracine hormones act on the SAME/OTHER cells that produce them. | other |
Neurotransmitters are released from | presynaptic axon |
3 characteristics of neurotransmitters | 1.act rapidly 2.over short distances3.short duration |
endocrine hormones are released by __________ into the ___________ and influence cells at a different location. | specialized glands or cells circulation |
3 characteristics of endocrine hormones | 1. act slowly 2. act over long distances3. long duration |
A hormone is a chemical that is secreted by | . a cell or group of cells . into the blood for transport . has a distant target where it exerts its effect . in low concentrations |
hormones are usually secreted by | endocrine glands |
other molecules that can act as hormones are secreted by | 1. isolated endocrine cells within tissues 2. neurons 3. immune system cells |
low amounts of hormones are OK because | hormones have a high affinity (low Km) for their receptors |
hormones bind to __________ and initiate a __________ | receptors response |
3 general classes of hormones | Proteins and Polypeptides Steroids Tyrosine derivatives |
Most abundant type of hormone in body | Proteins and Polypeptides |
Steroid hormones secreted by | adrenal cortex, ovaries & testes, placenta |
Steroid hormones | cortisol, aldosterone, androgens & estrogens, vit D |
Tyrosine derived hormones are secreted by | thyroid, adrenal medulla |
Tyrosine derived hormones | Epi, NE thyroxine |
peptide hormone size | 100 aa |
Peptide hormones synthesized on ___________ as ___________then cleaved to ___________ by peptidase in the ___ | polysomes, prehormones, prohormones, ER |
After being synthesized peptide hormones are transferred to the __________ for packaging into secretory vesicles | Golgi |
___________ in vesicles cleave prohormones into _____________hormones | enzymes, active |
vesicles release their contents into extracellular space or bloodstream via | Ca2+ dependent exocytosis |
Protein hormone secretion is RAPID/SLOW | rapid (sec-min) |
peptides are ________ soluble | H2O |
peptides have a LONG/SHORT half life | short |
peptides are lipo PHILIC/PHOBIC and CAN/CANNOT pass through the cell membrane (receptor cell) | phobic, cannot |
peptide hormones act on cells through | membrane surface receptors |
peptides hormones act on cells by initiating a | second messenger system |
2nd messenger systems have a RAPID response because they | modify existing proteins |
2nd messenger systems | G protein coupled receptorsenzyme linked receptors |
Steroid hormones are synthesized from ___________ and STORED/NOT STORED | cholesterol, not stored |
Steroid hormones are secreted SLOWER/FASTER than protein hormones | Slower - they have to be synth from cholesterol |
steriod synthesis occurs on the | smooth ER |
most cholesterol comes from | plasma lipoproteins |
T/F cholesterol can be made de novo | TRUE |
steroid hormones are lipo PHILIC/PHOBIC and CAN/CANNOT be stored | philic, cannot |
steroid hormones are released from the cell by | diffusion - lipoPHILIC |
steroid hormones are SOLUBLE/NOT SOLUBLE in body fluids | not soluble |
steroid hormones must be carried by ___________through the blood | protein carrier molecules |
steroid hormones bound to carriers are | protected from proteases not active |
in order for a steroid hormone to be active it must be BOUND/FREE from the carrier protein | free |
how does a steroid hormone cause an effect in the target cell | diffuses thru membrane and binds a receptor in the cytoplasm, receptor-hormone goes to nucleus and activates transcription of certain genes |
Tyrosine derived hormones act like peptide hormones | bind membrane receptors - epi, NE, Dopa |
Tyrosine derived hormones act like steroid hormones | bind intracellular receptors - thyroid h |
thyroid hormones increase _____________ in the _______________of a cell | transcription, nucleus |
factors that increase or decrease the amt of hormone in the blood | rate of secretion rate of clearnace |
hormones are cleared from the blood by | metabolic destruction by tissues binding target tissues excretion by liver in bile excretion by kidney in urine |
2 organs that aid in hormone excretion | liver, kidney |
down regulation of hormone receptors | decreases responsiveness |
upregulation of hormone receptors | increases responsiveness |
factors causing downregulation of hormone receptors | inactivation of receptors inactivation of 2nd msgr proteins temp sequestration of receptors in cell destruction of receptors by lysosomes decreased production of receptors |
hormone secretion stimuli | external circadian rhythms spontaneous sleep |
negative feedback | turns DOWN or OFF!more important in maintaining homeoprevents oversecretion prevents overactivity of target tissue |
positive feedback | turns ON or UP! |
part of brain involved in hormone production | hypothalamus |
hypothalamus is connected to _____________ by the ____________ | pituitary, infundibulum |
pituitary is under control of the | hypothalamus |
anterior pituitary hormones are controlled by _______________ & ______________ from the hypothalamus | hypothalmic releasing and inhibiting hormones |
hormone secretion from the posterior pituitary is controlled by __________________ that originate in the ______________ and end in the post pituitary | nerve signals, hypothalamus |
post pituitary hormones (from hypothtalmus) | ADH Oxytocin |
ant pituitary hormones transported from hypothtalamus to ant pit thru | hypothalamic-hypophysial portal vessels |
hypothalamus hormones acting on ant pituitary | TRH-thyrotropin releasing hormone CRH-corticotropin releasing hormone GHRH- growth hormone releasing hormone GHIH- growth hormone Inhibiting hormone GnRH- gonadotropin releasing hormone PIH- prolactin inhib hormone |
ant pituitary hormones | GH - growth TSH - thyroid stim ACTH - AdrenoCorticoTropin LH - leutinizing FSH - follicle stim PRL - prolactin |
principle endo areas | pineal, parathyroidthyroid, thymus, pancreas, adrenal stomach, sm. intestine, ovary / testes |
hormones prod by thyroid | thyroxine-T4, triiodothyronine-T3, calcitonin |
hormones prod by adrenal cortex | cortisol, aldosterone, androgens & estrogens |
hormones prod by adrenal medulla | Epi NE |
hormones prod by GI | gastrin, secretin, CCK, GIP, motilin |
hormones prod by brain | melatonin, MSH-melanocyte stim |
hormones prod by gonads | testosterone, DHT, estrogen, progesterone |
hormones prod bypancreas | insulin, glucagon, somatostatin |
hormones prod by parathyroid | PTH - parathyroid |
hormones prod by kidney | renin, erythropoetin |
hormones prod by liver | angiotensin |
hormones prod by heart | ANP - atrial natriuretic |
hormones prod by SKIN, LIVER, KIDNEY | Vit D (calcitriol) |
synergism | combined effect is greater than either of them individually - more than additive |
permissiveness | hormone A needs hormone B present to work properly |
antagonistic | hormones work against each other |
hypersecretion | adenomas or cancerous tumors of glands |
hyposecretion | anywhere in feedback pathway |
2nd msgr problems | tissues not responding to circulatins hormone levels |
primary hypersecretion is due to | problem at primary organ or gland |
secondary hypersecretion is due to | problem at pituitary or hypothalamus |
vasopressin | ADH |
ADH and Oxytocin are produced in the hypothalamus as | prohormones packaged with convertases in vesicles, cleaved by convertases while traveling down axon to be released |
ADH and Oxytocin are stored in ________ and exit the post pit. thru ________ | vesicles, exocytosis |
ADH is important in ______ regulation in the ___________ via the V2 receptor | H2O, renal tubules |
ADH plays a role in _________ regulation via the V1 receptor | blood pressure |
ECF osmolarity has what effect on ADH | INCREASES ADH - increases H2O reabsorption - decreases ECF Os. |
Oxytocin is very important during __________ and uses a POS/NEG feedback loop | partruition, pos |
positive feedback on oxytocin is caused by _____________ stimulis of the cervix | stretch |
__________ of cervix stops positive feedback of oxytocin | relaxation (baby is now out) |
oxytocin stimulates ______________ due to a nervous stimuli from breast | milk let down |
T/F each ant pit hormone has a specific target tissue | true |
hierarchical control | multiple points of hormonal control |
simple feedback control | one point of control |
prolactin action | stim prod of milk proteins, stim add mammary growth, promotes vit prod (liver), inhibits LH and FSH secretion (GnRH suppression) |
prolactin secretion stim by | suckling |
"normal growth" depends on | GH and other hormonesadequate diet, absence of chronic stress, genetics |
GH is produced by the | anterior pituitary |
GH exerts effectsA. on specific target tissues B. on all or almost all tissues in the body | B. all or almost all tissues in the body |
GH causes growth by | increased cell size, increased mitosis, increased # of cells, specific differentiation |
GH is ANABOLIC/CATABOLIC | anabolic |
GH is released from cells called | somatotrophs (GH=somatotrophin) |
GH metabolic effects | increased rate of protein synthesis, increased mobilization of FA's (use for E), decreased rate of glucose utilization BOTTOM LINE: enhance protein prod, reduce fat stores, conserves carbs. |
GH via IGF-1 effects | increases skeletal growth, strongly stim osteoblasts |
GH needs ________ & __________ to work | insulin and carbs |
Somatomedins function | indirectly mediate GH actions |
Stimulation of GH secretion | decreased blood glucose, decreased free blood FA's, starvation - fasting, protein deficient, trauma, stress, excitement, exercise, testosterone, estrogen, DEEP sleep, GHRH - stim |
Inhibition of GH secretion | increased blood glucose, increased free blood FA's, , aging, obesity, GHRH - inhib, growth hormone (exogenous), somatomedins |
GH and IGF-1 feedback on the _____________ or _____________ | anterior pituitary, hypothalamus |
GH is primarily released _______________ | in the sleep cycle |
GH is also released during | exercise |
GH has a direct effect on which organs and tissues | adipose, liver, muscle |
GH has an indirect effect, thru IGF's which are produced in the _________ and have effect on which tissues | liver;kidney, pancreas, intestine, islet cells, parathyroids, skin, connective tissue, bone heart, lung, chondrocytes, muscles(slide 67) |
GH deficiency can cause | . dwarfism(pre puberty), panhypopituitarism - inadeq secretion from ant pit, rate of dev decreased, decreased capacity to make cartilage and long bone, Laron dwarfism: GH hi, IGF-1 low receptor insensitivity |
GH deficiency is treated with | Human growth hormone (exogenous) |
GH excessive caused by | Pituitary adenoma |
excessive GH causes | Gigantism: adol onset, inc bone length & thickness, Acromegaly:adult onset, inc bone thickness, (nose, head, hands, feet), oragnomegaly. Pituitary diabetes:excessive insulin stim causes insulin insensitivity in tissues |
Pituitary diabetes is caused by excess _____ and entails | GH.TYPE II: overstim of insulin causes "insulin insensitive" tissues and dec glucose uptake, TYPE I: "burnout" of pancreatic B-islet cells |