puberty, estrous cycle, follicular phase

puberty

(F) body supports pregnancy req, high metabolic cost (M) minimum sperm #

limiting factor

hypo tonic/surge centers (AP) inject GnRH > FSH/LH (GONADS) inject > estrogens/testosterone

hypothalamus sex differences/development

(F) surge/tonic, fetal ovaries > estrogen > aFP bind > prevent brain entry > GnRH surge center > cyclic hormone release (M) tonic, fetal testosterone cross blood-brain barrier > E2 by aromatase > defeminizes brain > no GnRH surge

GnRH pulse generator

neuron group, in/external signal detection/integration > pulsatile GnRH release, KNDy neurons

post pubertal endocrine profiles

(F) tonic LH release, low amp/high freq, LH surge, prevovulatory E2 surges (M) no LH surge, low amp/high freq pulses, LH/T

human puberty/menarche

1st menstruation onset, genetics/ethnicity/nutrition/environment

precocious puberty, treatment

secondary sex characteristic onset/GnRH pulses increase gonadotropins/gonadal hormones, high GnRH agonist concentration > pituitary receptor prolonged activation > receptor internalization/desensitization > reduce FSH/LH/gonadal steroids/puberty

puberty nutrition/metabolism

(young) body maintenance primary, energy directed to vital functions (juvenile) metabolic rate decreases/storage (fat) increase, non-vital function energy available, excess energy supports puberty onset (METABOLISM) metabolic inhibitors treat blood glucose/FFA, estrous cycle disrupted, pulsatile LH secretion decreases, kisspeptin/leptin

leptin

white adipose tissue product, deficiency > pubery entrance failure

seasonal breeder puberty onset

birth season, photoperiod, body size/weight (SHEEP) naturally short day/fall (stimulate 1st estrus onset) breed anytime

(seasonally) polyestrus, monoestrus

(P) regular cycles, posssible pregnancy year round, fall/short day, spring/long day, cattle/swine/rodents (M) 1 cycle/year, dogs/wolves/foxes/bears

folliular/luteal phase

(F) CL regression > ovulation, short, follicles dominate ovary, E2 main hormone (L) ovulation > CL regression, 80% entire cycle, CL dominate ovary, P4 main hormone

proestrus, estrus

(P) ovulatory follicles > E2, P4 decreases (luteolysis), E2 increases at estrus onset, FSH/LH transition (E) proceptive/receptive behaviors, mating, ovulation during/after estrus

metestrus, diestrus

(M) P4 secretion, after ovulation, ruptured follicle differentiates > CL (D) sustained luteal P4 secretion, longest stage, CL fully functional, P4 high, luteolysis end

feline/canine reproduction

(F) induced ovulators, polyestrus, not seasonal, no copulation > postestrus, no ovultion/Cl form/mestrus/diestrus/luteal phase (C) vaginal swelling/blood inged discharge > LH/FSH peak > CL persist, gestation > low repro activity/P4

anestrus

no regular estrous cycles, ovaries inactive, no ovulatory follicles/CL, low GnRH > insufficient gonadotropin secretion, pregnancy/lactation/season/poor nutrition/stress/pathology

gestational/seasonal anestrus

(G) high P4 inhibits CL/placenta GnRH > low GnRH, no FSH/LH increase > follicle growth/ovulation suppressed during pregnancy (S) moderate temp favors/insures embryo/neonate survival

postpartum/lactational anestrus

(P) uterine repair/recovery time before next pregnancy, introduced
infection copulation protection (L) prevents new pregnancy before young weaned, ovulation/cyclicity inhibited, suckling degree influences length

silent estrus

ovulation w/o behavioral estrus, all farm animals

menstrual cycle

0-28 d, menses onset, midcycle ovulate, FSH/LH/E2/P4, granulosa follicular phase cells > inhibin B, granulosa luteal phase cells > inhibin A

anti-pathogen hypothesis-profet

removes sperm borne pathogens > prevents infection, protection > Fe/nutrient loss, (problems) blood grows infectious organisms, inefficient control means, pregnant/lactating/post menopausal unprotected

conversion of energy-strassman

Cyclical endometrial renewal uses less energy than maintaining constant implantation-ready state by lower endometrial O2 consumption

menstruation unnatural-coutinho

ancient women continually pregnant/lactating, increased cycles/estrogen/ovulation rate > high cancer incidence

menstruation suppression, benefits/risks

seasonale extended birth control pill (synthetic steroids decrease ovulation/endometrial growth) (B) pain relief, lower blood loss, anemia risk, ovarian cancer (R) short term blood clots/stroke/heart attack, long term future fertility/organ effects

follicular phase gonadtropin release

(PITUITARY) tonic basal GnRh secretion, FSH/LH > follicular growth,
surge preovulatory GnRh release, LH surge > ovulation (OVARY) E2 increase > GnRH release/follicular growth, ovulation > increase P4/decrease E2 > suppresses GnRH release

negative feedback control

hormone/estrogens decreases at own secretion rate, maintain homeostasis, tonic center sensitive to low E2 effects > GnRH/FSH/LH reduced > decreases E2 production

positive estrogen feedback

structural event stops loop/continued hormone production, tonic center negative FB estrogen sensitivity decreases > E2 increases > positive FB switch > surge center > GnRH/FSH/LH

follicular dynamics

(RECRUITMENT) small antral follicle growth > E2, FSH > LH, no inhibin (SECLECTION) medium antral follicle growth > more E2, FSH = LH, low inhibin (DOMINANCE) dominant follicles > high E2, FSH < LH, high inhibin (ATRESIA) follicular degeneration

follicular dynamics species

(MONOTOCOUS) single bearing, cattle/mare/women, single follicle > dominance (POLYTOCOUS) litter bearing, pigs/dogs/cats, multiple follicles > dominance

sexual receptivity, inhibin

elevated estradiol coupled w low progesterone, genital swelling, leukocytosis, increased genital secretion, uterine gland growth, elevated myometrial tone (I) decrease FSH at AP level

follicular waves

recruitment, selection, dominance, atresia waves continuous during estrous cycle, P4 declines at luteolysis > DF survive to ovulate

2 cell, 2 gonadotropin

estradiol synthesis, (THECA) LHR, produce T (GRANULOSA) FSHR, produce E2

menopause signs, why, result

(S) menstrual periods irregular/stop, hot flashes, bone loss, repro tract atrophy (W) fewer ovarian follicles, gonadotropin insensitivity, no follicle growth/ovulation
(R) circulating hormones/negative FB regulation changes, menstrual cycling cessation

menopause path

follicular gonadotropin insensitivity> low E2, inhibin, P4 production > negative FB
lack > elevated GnRH, LH, FSH