Ovary Structure

Outer layer

Ovary Structure

Outer connective tissue

Tunica albuginea

must break down for egg release and growth

Ovary Structure

the cortex

Ovary structure

Medulla

what senses that the female is pregnant

Ovary structure

Hilus

primordial, primary, to secondary, tertiary (growth and size of atrium makes them visible)

if ovulation occurs

corpus hemorragicum

corpus luteum

corpus albicans

at any stage the follicle cn degenerate

exocrine (produce eggs)

endocrine (produce hormones)

Tubal

Outer layer->serosa

two mucus layers -> inner circular, outer longitudinal (constricts and shorten to move contents)

Connective tissue-> submucosa (support vessels, nerves)

Mucosa-> single secretory layer, produces hormones, nutrients, fluid

(fallopian tube in humans)

convoluted tube

infundibulum-dilated, funnel shaped has fimbria to catch ova (fingers)

Ampulla-site of fertilization

Isthmus-reservoir

Uterotubular junction-restrits entry

Mesosapinx-as bursa, may surround ovary (supportive connective tissue)

layers:

Mucosa-changes in secretory ciliated epithelium

muscles-change to move gametes

Function:

fertilization

conveys sperm and eggs

early embryo development

Bicornuate-well developed uterine horns (swine, cattle, sheep, horses. cats, dogs)

simplex-no horns (humans, primates)

duplex-dual uterus and cervix (rabbits, rodents)

Didelphic-uterus, cervix and vagina are paired (Marsupials)

Endometrium

(mucosa layer)

continuous into glandular lining

structure shows carnucles, smooth, folds

(sub-mucosa) glandular lining producing hormones, fluids

changes in thickness and hormones change blood flow

Myometrium

response to hormones to alter contractions

• sperm survival transport and capacitation
• embryo development
• luteal regression
• fetal growth
• birth process

structure:

latin (Neck) thick walled

opening protrudes into anterior vagina in horse, cattle and sheep

canal with single, multiple folds or rings protruding into canal or can be smooth

dialted, soft at ESTUS, more rigid and closed during pregnancy, except at delivery

Fuction:

site semen deposit (direct pig, indirect horse)

sperm reservoir and filter, barrier

source of mucus, microbe barrier

birth canal

anterior: vestibule to cervix

vestibule: both urine and reproduction (urethral opening to Labia)

Muslce layer: poorly defined

Mucosa: epithelial layer thickest at estrus to protect during copulation and prevent microb entry, fluids contain immunglobulins IG A and G, lw in ph and has oders at estrus

Site for semen depositon/resuvior

passive birth canal

vulva-external

(Labia major/minor-hormone sensitive)

Clitoris-

erectile tissue, sensory nerves

Vestibular gland-

mucus secretion

broad ligament (holds in place)

ligaments continous with peritoneum

(connective tissue house blood vessels and nerves)

Mesometrium-uterus

Mesovarium-ovary

Mesosalpinx-oviduct

chages blood supply during cycle due to hormone

size as well from fluid retention

...

counter-current exchange

(artereis coild around veins to allow hormone transfer)

embryo germ cells migrate near embryo kidney

a third of the way through gestation kidney develops from metanephros+ureter) to mesonephricducts and paramesonephric

...

undifferentiated but male Y genes produce TDF (testies determining factor) and MIF that stimulates T and the metanephrons (Wolffian ducts) and testeis to form and para regress

...

female (XX) paramesonephric ducts develop by default

Nervous (simple reflex)

back pressure test

...

and

...

endocrine (slower but longer lasting)

oxytocin-milk

• hypothalamus
• pituitary
• ovaries
• uterus
• placenta

group specialized neurons located in clusters at base of brain produce GnRH

...

have axons terminating on capillaries and release GnRH into arteries which supply pituitary

small peptide (short aa)

being small alows easy changes and alter effect

Agonists-> activate receptor

Antagonist-> blocks receptor

induces large follicles

converts cholesterol to androgen

ovulation

glycoprotein along with FSH

follicular growth/health

coverts androgens to estrogen

glycoprotein along with LH

• both secreted from anterior pituitary
• glycoproteins
• each has subunits same alpha different beta chains
• 100 aa with carbohydrate side chain to increase half life
• cannot be given orally
• difficult to synthesize

neural tissue with nuclei organized in hypothalmus and axons synapsed on capillaries

produces oxytocin

• nano peptide
• causes smooth muscle contractions via receptors (not usable for partiution)
• half life of minutes

Primary steroid hormone (progesterone, androgen, and estrogen)

Primary protein hormones

inhibin (stops FSH from pituitary)

goes only one way (no backward)

cholesterol->progestagens->androgens ->estrogens

effects reproductive tissues with receptors

induces behavior, changes blood flow to reproductive tract by dialating artereis to increase flow and reduce drainage resulting in swelling/pressure

secondary sex characteristics -> mammary gland/breast development, hair

steroids tetra-cyclic ring (4)

glands synthesize prostaglandin

acts on smooth muscle to cause contractions and constiction of vessels

causes luteolysis

it is fetal+maternal membranes

produce progesterone,estrogens

glycoproteins (ecG human chorionic gonadotropin, and hcG equine chloronic gondotropin)

travel in blood via carriers (albumin or globulin) 

...

half-life

control duration of action

rapid cleared from kidney or liver based on size (carriers increase size)

production/clearence explains concentration in blood

...

bind external receptor and dissociates from cell to endter nuclear receptor

Rapid follicle growth

3-10 days

...

may begin with

CL regression

from non cycling

follicle dominaiton

...

progesterone and FSH declines, inhibin increases

large follicles present and estrogen

sexual receptivity/behavior change

post-ovulation

...

CH present and luteal cells begin to form (bloody muucus observed in heifers)

...

2 days

CL will replace CH

full CL formation takes place

5 days (approx)

max progesterone

(12-14 days)

multiple cylces all year round

cow, queen, pig, rodents

multiple cycles in one part of the year

...

short day (autumn)

ewe,doe, elk, nanny

long day (spring)

mare

one cycle per year

dog, wolf, fox, bear

21 days polyestrus

estrus-18hours

ovulates 30hours->(from onset of estrus to 10-14 hours after end)

3day proestrus

1day estrus

4day metestrus

15day diestrus

21 days seasonally polyestrus

Estrus 5-7days

ovulates in last 2days (1-2days before end of estrus)

proestrus 2day

estrus 5day

metestrus 2day

diestrus 12day

21 day polyestrus

estrus 2 days

ovulates 2/3rds through heat-mult follicles

proestrus 5days

estrus 2days

metestrus 2days

diestrus 12days

ewe-17, goat-21 days seasonally polyestrus (short day)

estrus subtle 1day(30hrs)

ovulates after end of 30hrs

5 day cycle if not mated

estrus 12 hrs (vaginal plug if mated within last 12hrs)

ovulates 12 hrs after onset spontaneous (night)

CL ONLY FORMS AFTER 5 DAYS OF PREGNANCY (P4 HIGH AT ESTRUS)

women-28day

chimp-25day

no estrus

count from day 1

slothing of endometrium (loss P4)

thickness increases with E2, then with P4

ovulation day 14

most will not cylce or express estrus during early lactation

sow-30days

cow-60days

weaning alows resupmtion of GnRH, LH and cycles

mares 1-2weeks after parturition!

senescence-aging

depletion of ova/follicles

hormone levels for FSH increase

most animals will not live long enough to deplete ova

women menopause is follicle depletion

monotocous species ovulation related to embryo production

litter bearing species ovulation related to litter size (18 fertilized and 14 embryos survive)

• small antral follicles have FSH receptors
• medium have FSH and LH
• Large have mostly LH

day 14

it is induced by LH

follicle development

estrogen feedback

estrus

GnRH increases in pulses

LH surge

cats, rabbits

may have breeding seasons based on favorable climates

vaginal/cervical tactile stimulations

induces neuroendocrine response to release GnRH and LH

the egg/ovum:haploid

the ootid:

single cell with 2 nuclei

(male and female pronuclei)

the Zygote:

pronuclei fuse

2 cell-18h

4 cell-32h

8 cell-54h

(may enter uterus 48-72 hours)

morula-4d

blastocyst-7d

hatching-8d

unequal

1st-embryo stage (no limbs)

2nd-fetal stage (recongnizable species form)

3rd-growth stage

No, in early development (cleavage stage embryo - Morula) the zona pellucida (covering) prevents growth

...

cells (blastomeres) increase in number and reduce in cell size

...

blastomeres from 2-8 stage are totipotent and can be transferred to any empty zona (Cloning)

Blastomeres form inner cell mass (ICM) which forms inner organs, glands, muscle and skeleton

Blastomeres (ICM): form gap junctions, will create organs, glands, muscle, and skeleton

...

Trophoblast: tight junction, placenal membrane, neural, sense organs, skin

...

Blastocoele cavity

...

Hatching, trophoblast weakens zona on day 6-12 allowing growth-elongation to cover uterus-which stops prostaglandin

both allow for increased movement of nutrients and gases...and thus placenta develpoment

attachment-livestock species

implantation-rodents and humans

-embryo/fetus and membrane (that provide protection, hydration, and growth space)

amnion-innermost, fluid filled

allantois-fused with chorion forming allantochorion-fluid filled

chorion-outermost-attached to uterus

YES! just to make things more confusing

classified by location of villi

diffused (pig, horse)

cotledonary (cow, ewe, ruminants)

zonary (dog, cat)

discoid (primates, rodents)

classified by number of layers between blood supply

epitheliochorial (livestock)-chorion and endometrium cells in direct contact each has basment membrane separating capillary supply

endotheliachorial (dog/cat)-chorion cells in direct contact with endometrial capillary

hemochorial (rodents/primates)-pool of endometrial blood exposes chorion cells

transport of small molecules-in/out

hormone production

equine chorionic gonadotropin

placenta produces-d35-60 forms accessory CL increasing progesterone

FSH-like activity in other species

human chorionic gonadotropin

human/primates: tropoblast cells produce d7-70 stimulating existing CL to produce progestrone

...

LH like in other species

used to induce ovulation

1. preparatory, removal of myometrial block (hormone sequence, cervical (relaxin produced by CL or placenta-softens connective tissue in cervix ligament/pelvic) dilation, uterine contrations(placental estrogen ,increase oxytocin recoptors-1 contraction every 2 min))

...

2. expulsion of fetus-water breaks, membranes (allantois/amnion) enter cervix, umbilical cord breaks from placenta (Dystocia can occur at this point)

...

3. expulsion of membrane-contractions end, vasoconstriction of arteries (pressure loweres and villi detach/membranes dislodge, prevents hemoraging. In minutes to hours membrane shed

uterine repair (shrink so can once again transport sperm)

restore muscle tone

new lining forms for uterus

ovarian activities resume

hypothalmus/pituitary function

prepubertal

transitional

post-pubertal

mature

puberty is the start of process and fertility improves with age

puberty:2/3rds mature body weight, neuroendocrine system shifts from hormones driven growth to reproduction

 sensitivity to GnRH/FSH/LH, steroid production and feedback

most domestic animals were once seasonal and many wild animals still are

proximity to the equator reduces photoperiod changes

Optimal time to concieve/birth

related to 24 hour cycle

(diurnal/nocturnal)

hormone change in night even for humans

melatonin spikes at night from pineal gland and helps you sleep

long nights-increase pineal melatonin, GnRH and FSH/LH, also low firing of retinal nerves

ovulation test

uses blood, salviva, urine to test for LH

predicting ovulation based on temp changes

hCG or LH act on follicle directly

GnRH works at Pituitary

large follicle must be present for either to work

non-infectious (heat stress, toxins etc)

infectious (viral, bacterial, fungal)

inflammation or infection of the uterus

most common postpartum

(pyrexia and anorexia)

fluid accumulation and fertility failure, dishcharge (bacterial infection)

poor tract structure, hygiene