Female Reproductive Anatomy

- membrane consisting of a single layer of simple squamous epithelial cells (mesothelium) and a small amount of underlying connective tissue

Muscularis externa

 – layers of smooth muscle, usually layered with outer longitudinal and inner circular muscle

Function – provide tone and contract for transport (gametes, embryo, parturition, secretory products

Types of Epithelium

Types of Epithelium - Organization of cells

1. simple – one cell layer

2. stratified – consisting of two or more cell layers

3. pseudostratified – appears stratified, some cells do not reach ther free surface but rest on the basement membrane

Types of Epithelial cells

1. columnar – height of cell exceeds the width and depth

2. cuboidal – width, depth and height are approximately the same

3. squamous – width and depth of the cell is greater than the height Epithelial cells can be ciliated or nonciliated.

is further specialized depending upon what organs it is associated with:

1. Portion attached to the ovary – mesovarium attaches to the hillus of the ovary

2. Portion attached to the oviduct – mesosalpinx

3. Portion attached to the uterus – mesometrium

1. Exocrine gland – secretes into a duct, eggs

2. Endocrine gland - produces hormones that go directly into the blood stream, estrogen, progesterone, relaxin, activin, ocytocin, inhibin

Portion of the broad ligament that supports the ovary – mesovarium, the ovary is suspended in the body cavity Ovary shape – cow - almond, sow -bunch of grapes, mare - bean shaped

 – outer, functional tissue portion or parenchyma

follicles are found in the cortex and develop in this area along with the ova, copora lutea (CL) are found in the cortex region

– outer to inner

Germinal epithelium – simple (single) layer of cuboidal epithelial cells

Tunica albuginea – connective tissue layer, tough, white in appearance

Hillus – base of the ovary, attaches to the mesovarium, entry and exit point of blood vessels, nerves and lymphatics

A. Follicles and their derivatives

B.Population of undifferentiated cells from stroma origin that can give rise to

1. theca cells of follicles upon differentiation become associated with follicles

2. interstitial cells – endocrine cells present in cortex in scattered aggregates both cell types are a form of endocrine cells, some species variation

– several types of follicles, a follicle undergoes steps of maturation before ovulation

Definition – a cellular envelope about the ovum/oocyte Nearly all follicles are formed in fetal life Females have the greatest number of ova as a fetus, once this peak is attained, the number declines with time/age due to follicular degeneration and atresia Example – cow at birth 60,000-100,000 ova in both ovaries; at ovarian senescence – a few hundred

Atresia – follicular degeneration

oocyte has attained full size follicle cells –two or more layers and these cells are actively dividing for proliferation

zona pellucida – acellular glycoprotein layer secreted by oocyte and follicular cells that surrounds the oocyte, important in sperm recognition of the oocyte

theca folliculi – endocrine cells that associate with follicle become theca cell layer

theca externa – cells and connective tissue layer

theca interna – endocrine cells, receptors for LH, produce androgens, vascular region

membrana granulosa – granulosal (granulosa) cell layer of original layer of follicle cells, have continued to proliferate, multilayer and are now known as granulosa cells, have receptors for FSH, produce estrogen, activin, inhibin produce fluid to form an antrum

Antrum – fluid filled cavity Basal lamina (basement membrane) has formed separates the thecal from granulosa cell layer

 – largest follicle, visible on surface of the ovary, fluid antrum has enlarged, filled with more fluid so appears as a blister protruding or bulging from ovarian surface some cells have become specialized – recall theca interna, specialized granulosa cell immediately surround the oocyte – called cumulus oophorus oocyte sits on the hillock, granulosa cells that support the oocyte The orientation of the oocyte is opposite the surface of the ovary

CL- Corpus luteium: produces progesterone; yellow body

Corpus Hemorrhagium- immediatly after ovulation, bloody body. 

Corpus albicans- regressed CL; no known endocrine function

Made up of several structures – fimbria, ostium, infundibulum, ampulla, isthmus, ampullary-isthmic junction (AIJ), uterotubal junction (UIJ)

Delicate, tube-like structure extending from the uterus to the ovary connected with the uterus but not the ovary

mesosalpinx supports the oviduct

(opening) of infundibulum which is a funnel shaped opening of the oviduct

Ampulla

 – first half of the oviduct, large lumen mucosal surface area is very large due to folds epithelium of mucosa is

a. simple columnar ciliated, 

b. simple columnar nonciliated cells - secretory

c.intercalary (Peg) cells - Peg cells are depleted, collapsed secretory cells after secretion is voided and the nucleus gives them a Peg appearance

ampullary-isthmus junction (AIJ) 

-junction of Ampulla and Isthmus is the AIJ

– approximate site of fertilization sperm and oocyte transported through oviduct

-Early embryo development occurs in the oviduct (2-5 days)

Prominent organ of the female reproductive tract, organ of pregnancy Support– mesometrium is the Broad Ligament supporting the uterus. 

1.serosa – perimetrium

2.muscularis – myometrium

3. mucosa – endometrium

Duplex

-Two seperate uterine horns and cervix. no communitcation between them. 

-Rodent, rabbit, marsupials (didelphic)

-No Unterine Body

-Small to medium uterine body

-One cervix

-large, communication between horns, rumninants share septum (intercorneal ligament)

-Sow, dog, cat, mare ruminants (bipartite)

-Very large uterine body

-no uterine horns

-primates

– outer tissue layer, simple squamous epithelium and connective tissue

 – uterine mucosa, two distinct cell types

a. ciliated simple columnar epithelial cells

b. secretory cells found in tubular glands that penetrate the submucosa

 –  Biochemical secretions that aid in the nutrition of the embryo and sperm viability. 

 - highly vascularized, raised button like structures in ruminant uterine mucosa.

-Fuses with cotyledons to form placentome

1.location of early embryo development

2.location of embryo implantation

3.location of placenta formation – placentation

4.produce factors in secretions that are important for fetal nutrition

5. Undergo size changes to accommodate the fetus and fetal growth

6. Muscle contractions – sperm transport fetal expulsion during parturition uterine involution

7.Luteolytic effect: No embryo present - the uterus produces prostaglandin F2a (PGF2a) which causes the CL to regress. Female returns to estrous cycle and has another chance at getting pregnant.

8. Immunosuppressive effect – suppression of immune system to avoid rejection of the fetus.

-Rigid portion of female tract Dense connective tissue with small amount of smooth muscle

-Lumen of cervix in ruminents: Annular rings – finger like projection that act to seal the cervical lumen

Lumen of cervix in swine – rings are called interdigitating prominenses and boar penis becomes locked

Serosa – outer layer, thickest layer with dense connective tissue, rigid

Muscularis externa - middle layer, thin smooth muscle, irregular arrangement

Mucosa – simple columnar epithelium- Some cells are ciliated, nonsecretory

Goblet secretory cells

 – secretory nonciliated cells, responsive to hormone fluctuations

Secretions - function in keeping foreign material out of uterus and lubrication in vagina

Crypt(s) 

1. transportation vehicle for sperm (mucus)

2. select viable sperm

3. sperm reservoir – sperm can be found localized in the crypts 4. prevents entry of foreign material into the uterus

5. expansion/dilation during parturition – enzymatic degradation of connective tissue

Region between the external vestibule and cervix

Two regions – cranial vagina and caudal vagina (vestibule) Functions:

1.Copulatory organ – sight of semen deposition in many species with exceptions

2. passageway for fetus at parturition

Histology/Tissue organization of Vagina

1.Serosa/adventitia – simple squamous epithelium with connective tissue, blends into the peritoneum

2.Muscularis externa – smooth muscle for contractions, inner circular, outer longitudinal, layers are discrete but disorganized

3. Mucosa/epithelium – varies depending on location cranial – simple columnar epithelium, ciliated & secretory

fornix vagina – columnar, secretory caudal – stratified, squamous epithelium, thickens during estrus, protection during copulation (bacteria)

Keratin is a tough protein found on the epithelia surface Induced (reflex) ovulators

-male has spiny processes on penis that irritates vagina and induces a hormonal responses that lead to ovulation 

– outermost portion of the vagina, the urethral orifice is the dividing line between vagina and vestibule, changes in mucosa are apparent

Part of the urinary system and extends to the vulva

Vestibule has some scattered secretory cells but vaginal fluid is made up of cervical secretions, subaceous and sweat glands

 – secrete lubricating secretions which contain pheromones during estrus

Cow: left and right glands, single excretory duct

Horse and pig: multiple minor glands with large number of small excretory ducts

– fetal vestige of the Wolffian duct, the Wolffian duct becomes the ductus deferens in the males and degenerates in the female

Glands/Structures in vagina

 – blind pouch of unknown function, situated at the ventral aspect of the junction of the vagina and vestibule, located caudally of the urethral orifice

Vestibule (Glands of Bartholin, urethral orifice, suburethral diverticulum and Gartner’s tubules)

Labia (majora and minora collectively known as vulva),

clitoris

Vulva – labia major and minor

Only visible part of reproductive tract

hormonal fluctuations - hyperemic (blood engorged) and reddened in estrus Pale, reduce when progesterone high Function is to separate the reproductive tract from the outside world

– analgous to the male penis, some erectile tissue, stratified squamous epithelium, prepuce surrounds the clitoris and attaches to the dorsal aspect of the glans

Three parts – glans, corpus, root