SFP: female reproductive histology Flashcards
What is the epithelium of the ovary?
A germinal epithelium that is simple cuboidal
Beneath the germinal epithelium, there is a layer called ___
Tunica albuginea
Describe the cortex of the ovary.
Contains a vascular connective tissue stroma and follicles at various developmental stages
Describe the medulla of the ovaries.
Loose connective tissue with lots of blood vessels, nerves, lymphatics
Describe the hilum of the ovary.
The entry/exit point of ovarian artery, vein, nerves, and lymphatics
What is an ovarian follicle prior to puberty?
A primary oocyte surrounded by follicular epithelium; maintained in the primordial stage prior to puberty
What kind of epithelium is follicular epithelium?
Simple squamous
Describe a primordial follicle.
A primary oocyte arrested in prophase I of meiosis found in the outer region of the cortex of the ovary
Describe the first stage of follicular development.
A growing primary oocyte still in prophase I surrounded by 1-2 layers of follicular cells (granulosa cells) in a cuboidal shape
What is the zona pellucida?
A glycoprotein coat that develops as the primary oocyte enlarges
Describe the secondary stage of follicular development.
A follicle with more than two layers of granulosa cells connected by gap junctions. The primary oocyte continues to grow, it still arrested in prophase I, and the zona pellucida gets bigger. Granulosa cells secrete follicular fluid enriched in steroid hormones, growth factors, proteoglycans, etc
Describe the stroma in the secondary stage of follicular development.
It differentiates into the theca interna and theca externa
What is the function of theca interna?
Functions as an endocrine gland and secretes androstenedione that is converted to estradiol
What is the function of theca externa?
Fibromuscular outer coat
What are antra?
Fluid-filled cavities in the granulosum in secondary follicles
Describe the tertiary phase of follicular development.
The antra combine to form one big antrum, granulosum cells push to the periphery, with the primary oocyte remaining attached to/enveloped in the granulosum. The theca interna and externa are super prominent.
What is the corona radiata?
The layer of granulosa cells in contact with the zona pellucida in a tertiary follicle; they are connected to the oocyte via gap junctions
What happens to the corona radiata in a secondary oocyte?
It remains attached
What is the cumulus oophorus?
A stalk of cells connecting the primary oocyte to the granulosum in a tertiary follicle
What are ZP cells?
Cells of the zona pellucida produced by both the oocyte and granulosa cells that serve as sperm receptors
What happens to follicles that do not reach full maturity to undergo maturation?
They undergo atresia; oocyte degrades, and granulosa cells die
When does the first mitotic division of the primary oocyte occur?
Just before ovulation, along with 1st polar body; secondary oocyte is what is ovulated and 1st polar body gets degraded
Describe the process of ovulation.
- Granulosa cells ramp up prostaglandin, hyaluronan synthesis
- Mature follicle bulges and forms a finger-like projection on the surface and a stigma on the tip of the projection
- Plasmin weakens germinal epithelium and tunica albuginea
- Smooth muscle contraction in the tunica externa is triggered by prostaglandins
- Follicle ruptures and secondary oocyte is expelled
What is the corpus luteum?
A temporary endocrine gland formed from the granulosa cell and theca interna after ovulation
What does the corpus luteum do?
Secrete estrogens and progesterone
What are the parts of the corpus luteum?
Granulosa lutein and thecal lutein cells
Describe granulosa lutein cells.
Differentiated granulosa cells that make up most of the corpus luteum and secrete progesterone and promote conversion to estradiol
Describe the theca lutein cells.
Differentiated theca interna cells found in the folds of the corpus luteum that make androstenedione
What is the corpus albicans?
Degenerated corpus luteum from the remaining unfertilized ovum that forms scar tissue
What is the fate of the corpus albicans?
Gradually gets absorbed by macrophages
Describe the infundibulum of the fallopian tube.
Funnel-shaped portion near the free end of the ovary with projections called fimbriae
Describe the ampulla of the fallopian tube.
Longest part of the tube with a highly folded mucosa
What is the normal site of fertilization in the fallopian tube?
The ampulla
Describe the isthmus of the fallopian tube.
Short, narrow portion entering the uterine wall
Describe the intramural portion of the fallopian tube.
Traverses the uterine wall and opens into the lumen of the uterus
What are the layers of the oviducts?
Mucosa, muscularis, serosa
Describe the mucosa of oviducts.
Simple columnar epithelium with cilia; the mucosa of infundibulum and ampulla has longitudinal folds
Describe the histology of the isthmus.
No longitudinal folds, more peg cells, complete inner and outer muscularis layers giving it a thicker wall and smaller lumen
Describe the muscularis of oviducts.
Inner circular and outer longitudinal layers that facilitate transport of the oocyte
What are peg cells?
Secretory cells in the epithelium of oviducts
What are capacitation factors?
Stuff secreted by peg cells that helps sperm cells to be able to bind to eggs
Compare longitudinal folds in the infundibulum and oviduct.
They are smaller in the ampulla, but more numerous
What is the internal os?
Opening between the lumen of the uterus and cervical canal
What is the external os?
Opening of the cervical canal into the vagina
Describe the endometrium.
Mucosal layer of the uterus containing tubular glands, simple columnar ciliated epithelium, and stroma
Describe the myometrium.
Thickest layer of the uterus aka the muscle layer with an inner longitudinal, middle circular, and outer longitudinal layer
Describe the perimetrium.
Serosa with connective tissue
What are the layers of the endometrium?
Basalis and functionalis
Which layer of the endometrium remains following menstruation?
The basalis
Describe the endometrium in the proliferative phase.
The stroma and functionalis are restored, uterine glands are straight and narrow, endometrium in 2-3 mm thick
Describe the endometrium in the secretory phase.
Uterine glands become dilated and coiled, endometrium reaches maximum thickness, blood-filled lacunae form in the functionalis
The secretory phase is synchronized with…
Ovulation and production of progesterone by the corpus luteum
Describe the menstrual phase.
Drops in progesterone and estrogen cause spiral arteries supplying the functionalis contract and release prostaglandins, causing vasoconstriction and hypoxic injury. Blood vessels rupture, endometrium becomes partially detached.
What are arcuate arteries of the endometrium?
Those that branch from the uterine artery and are found on the edges in the middle layer of myometrium
Arcuate arteries give rise to ___ and ___
Straight arteries and spiral arteries
What are straight arteries?
Supply the basalis
What are spiral arteries?
Supply the functionalis
What is the transformation zone?
An area in the cervix where simple columnar epithelium changes to stratified squamous epithelium; usually just outside the external os
What causes a lower pH in the vagina?
Lactobacilli metabolize glycogen that accumulates in response to estrogens to lactic acids, lowering the pH
What mucosal glands are in the vagina?
None! Mucus secretions are derived from cervical glands
Describe the muscularis of the vagina.
Composed mostly of longitudinal bundles of smooth muscle fibers, with some circular bundle present
Does the vagina have adventitia or serosa?
Adventitia
