ANSC 224 Exam 2

Soluble vs insoluble hormones

soluble - proteins; insoluble - steroids/fatty acids

what receptors do proteins bind?

external receptor

what receptors do steroids/fatty acids bind?

nuclear or cytoplasmic receptor

albumin

non-specific protein carrier

SBP or globulins

specific protein carrier

where are the endocrine cells that control reproduction?

pituitary, ovary, and placenta

what do protein carriers and CHO chains do?

increase size and extend T1/2

where are small molecules cleared?

kidney

where are large molecules cleared?

tagged in liver to pass in urine

ng/mL hormones

insulin, FSH, LH, progesterone

pg/mL hormones

estradiol

mg/mL stuff

albumin/glucose, amino acids, peptides, lipids

LH positive feedback hormone

estrogen

LH negative feedback hormone

progesterone

GnRH released from…

hypothalamus

melatonin is released from…

pineal gland

gonadotropins and prolactin are released from…

anterior pituitary

oxytocin is released from…

posterior pituitary

steroids and protein hormones are released from…

ovaries and placenta

prostaglandin is released from…

uterus

GnRH

quick pulses and feedback control; cleared quickly (hard to measure)

oxytocin

slow pulses, no feedback control; causes contraction; minutes half life

LH

pulses; feedback control; produced by anterior pituitary gonadotrophs

FSH

no pulses, feedback control; produced by anterior pituitary gonadotrophs

peptide hormones (v small)

GnRH, oxytocin

protein hormones

inhibin, relaxin

glycoproteins hormones

FSH and LH

C pathway

cholesterol (C27) → progesterone (C21) → androsteredione (C19) → testosterone (C19) → estradiol (C18)

relaxin

small polypeptide dimer; produced by CL/placenta; dilates birth canal near delivery

are sex steroids stored?

no

mitochondria C production

C21

smooth ER C production

C21 or C19 or C18

progesterone

stimulated by LH in follicle or CL; closes cervix and uterine gland development

androgens

follicle produces androsteredoine and testosterone; intermediates in pathway to estrogen in females

most potent estrogen

estradiol (E2)

estrogen

dilates arteries/constricts veins

prostaglandin

induces contractions; constricts blood vessels to destroy CL

eCG is like…

FSH

hCG is like…

LH

senescence

end of cycle in animals

seasonal polyestrus (long day)

mare

seasonal polyestrus (short day)

sheep, cat

monoestrus

dog

polyestrus

cow, pig, rodents

when is metestrus?

at ovulation; CH present

diestrus

luteal phase; progesterone increases

which species don’t have luteal phase?

rodents and dogs/cats

monotocous

ovulate one dominant follicle

polytocous

ovulate multiple large follicles

follicle phase dominant follicles

early proestrus - NONE have dominant follicles; late proestrus - ALL have dominant follicles

follicle development type in cattle

wave type

what cells does LH induce?

theca and granulosa cell

is luteal cell progesterone production LH dependent?

yes

myometrium

thick, middle layer of uterus wall

myometrium stimulatory control hormones

estradiol, oxytocin, prostaglandin

myometrium inhibitory hormones

progesterone - reduces oxytocin and estradiol

what species is the uterus not the source of prostaglandin?

humans, dogs, cats

oocyte

developing egg

zona pelludica

thick glycoprotein coat to prevent polyspermy in mammalian eggs

when does final egg maturation occur?

after LH surge - first polar body expelled, secondary oocyte formed

what cells do sperm penetrate?

cumulus/corona cells

what do sperm cells bind?

bind vitelline membrane → 2nd polar body expulsion

acrosome reaction

block other sperm

zygote

sperm + egg fuse

natural site of breeding

vagina and uterus

AI site of breeding

uterus; cervix in pigs

what do sperm bind to establish reservoir?

bind isthmus/ampulla in oviduct

where are ovulated eggs transported?

ampulla

cleavage stage embryo

doubles cells every 18h

blastocyst embryo stage happens after…

7 days

inner cell mass

blastocyst forms with gap junctions → internal organs, skeleton, muscle

trophoblast

blastocyst forms from outer cells w tight junctions → placental membranes, neural, skin, sense organs

cloning

totipotent from 2-8 cell stage

blastocyst hatching

enzymes in trophoblast weaken zona

embryo membranes inner to outer

amnion, allantois, chorion

blastocyst hatching days for specieis

day 7 - pigs and human

day 8 - sheep and horse

day 9 - cow

embryo expansion shape species

spherical → elongated - pigs, sheep, cattle

spherical → larger - horse, human, dog, cat, rodent

what do horse embryos do after getting larger?

float to cover uterus

species pregnancy signals

dog, cat, rodent → CL forms

what binds the endometrium to attach the embryo?

trophoblast

what species have embryo implantation?

rodents and primates

follicle cell that produces androgen

theca

euthria

placental

metatheria

no placenta; opposum + kangaroo (marsupials)

prototheria

egg-laying mammals

mesometrium

supports uterus

mesosalpinx

supports oviduct

mesovarium

supports ovary

edema

swell from fluid retention

a counter current hormone that passes across vessels

prostaglandin

serosa

outer single layer of flat cells

submucosa

changes thickness and secretions by cycle stage

mucosa

single layer of epithelial cells lining tubes (most inner membrane)

bifurcation

separates uterine horns

endometrium

mucosa + sub-mucosa, caruncles (ruminants)

myometrium

2 distinct cell layers of muscle

uterine smooth muscle layers

outer longitudinal, inner circular

bicornuate

2 horns

simple

no horns - primates

duplex

no body, 2 horns - rabbits and some rodents