P1. Morphology of Female Reproductive Tract
The female reproductive tract is a series of tubes
- each tube is organised into concentric layers
- serosa (outer)
- covers the surface of the reproductive tract
- muscularis
- outer longitudinal layer, inner circular layer
- provides the tubular components with the ability to contract
- important for transport of secretory products, gametes, and early embryos
- submucosa
- contains blood vessels, nerves, and lymphatics
- mucosa (inner)
- secretory layer
The broad ligament supports and suspends the ovaries, oviduct, uterus, cervix, and anterior vagina
Components of the broad ligament are:
- mesovarium
- cranial portion
- supports the ovary in addition to the utero-ovarian ligament (UOL present in most species)
- mesosalpinx
- supports the oviduct (salpinx)
- forms a bursa-like pouch surrounding the ovary
- mesometrium
- largest part
- supports uterine horns and the body of the uterus
- dorsal portion is continuous with the dorsal peritoneum
Structures of the ovaries undergo constant change
Primary ovarian structures are:
- primary follicles
- primordial follicles develop into primary follicles
- have an oocyte surrounded by a single layer of cuboidal epithelium or follicular cells
- microscopic
- secondary follicles
- have an oocyte surrounded by two or more layers of follicular cells, WITHOUT an antrum or cavity
- microscopic
- antral follicles
- has a fluid-filled cavity called the antrum
- corpora lutea
- produces oxytocin, relaxin, inhibin, activin
- corpora albicantia
- degrading corpus luteum
NB - medulla of the ovary of the mare is on the outside, containing blood vessels, and the cortex is on the inside (looks like testes)
The oviduct consists of:
- infundibulum
- terminal (cranial or ovarian) end of the oviduct
- surface is covered with finger-like projections called fimbriae
- increase the surface area of the infundibulum and cause it to glide over the entire surface of the ovary at the time of ovulation to increase the chance of “capturing” the oocyte through the ostium
- ampulla
- oocyte travels through the ostium into the ampulla
- occupies > 1/2 oviduct length & large in diameter
- has many fern-like mucosal folds with ciliated epithelium
- site of ovulation
- isthmus
- smaller in diameter in comparison to the ampulla
- has thicker muscular wall and fewer mucosal folds
- transport newly ovulated oocytes and spermatozoa to the site of ovulation (ampulla)
- uterotubular junction is the junction between the isthmus and the uterine horn
Types of uteri found in mammals
- duplex
- two cervixes
- e.g. marsupials, rabbits
- bicornate
- single cervix
- two horns
- poorly to moderately developed uterine horns e.g. mare, cow
- highly developed uterine horns e.g. bitch, queen, sow
- simplex
- single cervix
- no uterine horns
- e.g. primates
The cervix provides lubrication, a flushing system and a barrier during pregnancy
- relatively thick-walled, non-compliant organ
- serves as a barrier to sperm in the ewe, cow, bitch, queen, not sow or mare
- isolates the uterus the from external environment during pregnancy by forming a barrier consisting of highly viscous mucous
The vagina is the copulatory organ
- for copulation and expulsion of urine during micturition
- passive birth canal during parturition