Reproductive Anatomy of mare - TAMU - ANSC 201- Schobert

mare reproductive tract can be divided into two groups of organs

true

two groups of organs for reproductive tract

reproductive tract, pituitary and hypothalamus

reproductive tract

ovaries, oviducts,uterus,cervix,vagina

pituitary and hypothalamus

hormonal regulation

how is reproductive tract shaped?

Y or T

each arm of reproductive tract consists of what?

ovary, oviduct, uterine horn

the trunk of reproductive tract consist of what?

uterine body, cervix, vagina, vulva

suspensory ligaments

supports structure of reproductive tract, road for blood vessels and nerves

how is reproductive tract attached to the abdominal wall

with two large ligament sheets called broad ligaments

each broad ligament forms a continuous sheet

true

there are 3 areas to broad ligament

true

mesometrium, part of broad ligament

attaching to uterine horns and uterus

mesovarium, part of broad ligament

attaching to the ovaries

mesosalpinx, part of broad ligament

attaching to oviducts

ovaries

kidney shaped, size of golf ball, master organ of tract, site of ovulation, releases hormones necessary for reproduction and pregnancy

site of ovulation

follicle ruptures to release an ovum

ovaries

unlike any other domestic livestock, cortex is the outer later and medulla is inner layer, constantly changing

where does ovulation occur?

anywhere along the cortex

medulla

outside of ovary

coretex

inside ovary, makes contact with outer layer of ovary

location where cortex makes contact with outer layer of ovary

ovulation fossa

there are other ovulation sites besides the ovulation fossa

false

corpus luteum

what the follicle becomes after ovulation, CL is destroyed, new follicles develop, ovulation occurs again

length of a follicle

2-50 mm

degenerating CL

corpora albicantia

mature follicle

graanfian follicle

at any one time the ovary can contain what?

mature follicle, regressing follicle, developing follicle

primary follicle

start as primary follicles, females born with lifetime supply, either degenerate or develop into secondary follicles

secondary follicles

no antrum (cavity), zona pellucida

zona pellucida

covering of the oocyte

antral follicle

fluid filled cavity, called a tertiary follicle

what is an antral follicle called when it becomes a dominant preovulatory follicle?

graafian follicle

cervix

protects uterus from pathogens are infection, used in AI

how is cervix located?

vaginal palpation, called little volcano

characteristics of horse cervix

different from cows, contains cervical folds, makes AI easier

horses have cervical rings

false

vagina

15-20cm long, extends from cervix to urethral orifice, transverse fold is more distinct in young mare

what does transverse fold form?

hymen

characteristics of vagina

highly elastic, fibrous tissue (strong and durable), normally collapsed except during breeding and foaling

vulva

external opening to reproduction tact, vertical opening directed under anus, provides first barrier against foreign material, very elastic

how long is vulva

12 cm long

poor reproductive conformation of a vulva

sunken vulva, poolers and urine poolers, allows urine and feces into vagina,

caslicks

the surgical procedure to close the upper portion of the vulva in the mare

hypothalamus

located at base of brain, middleman between nervous system and endocrine system, site where sensory info is incorporated and used to regulate endocrine output

pituitary gland

attatched ventrally to the hypothalamus, protected in a bony recess at base of brain

two main parts of pituitary gland

anterior and posterior

Neurons from the hypothalamus that terminate in the posterior pituitary

hormones enter the blood vessels and carried throughout the body to function as hormones

Neurons from the hypothalamus that terminate in the anterior pituitary

hormones are carried to endocrine cells of anterior pituitary to stimulate or inhibit the release of other hormones

oxytocin

A hormone released by the posterior pituitary that stimulates uterine contractions of smooth muscle fibers during childbirth and milk ejection during breastfeeding

reproductive hormones of anterior pituitary

prolactin, FSH, LH

prolactin

initiates and maintains pregnancy

gonadotropic hormoes

FSH and LH

luteinizing hormone (LH)

testosterone production in stallion, ovulation in mare

Follicle-stimulating hormone (FSH)

spermatogenesis in stallion, follicular growth in the mare

hypothalamus releases GnRH

causing the release of LH or FSH

simple neural reflex

stimulus - thermal, tactile, visual