Lecture 5: Histology of the Female Reproductive System Flashcards
What are the female reproductive system functions?
- Female gamete production
- Male gamete reception
- Provide environment for fertilization
- Provide environment for implantation
- Nourishes fetus
- Expels mature fetus at the end of pregnancy
Where are the follicles located in ovary?
The cortex of the ovary
What is located in the medulla of the ovary?
The vasculature
What are the two major functions of the ovaries?
- Produce female gametes
2. produce steroid hormones to prepare endometrium for conception
What is the difference between primordial follicles and primary follicles?
Primordial follicles = arrest at prophase of M1
-oocyte surrounded by one layer of granulosa cells
Primary follicles = developed during puberty
-oocyte surrounded by 2+ cuboidal epithelial cells
What is the zona pellucida?
A thick layer of glycoprotein
Secreted by granulosa/oocyte
Occupies space between oocyte and granulosa cells
What are the different stages of the female follicles?
- Primary follicle
- Secondary follicle
- Mature follicle
(ovulation) - corpus luteum
What stage is female gamete arrested in?
Oocyte in prophase of meiosis I
What is a follicle?
- Germ cell
2. Surrounding follicular cells
What is the antrum?
Fluid space in follicle
Characteristic of secondary follicle
What is a graafian follicle?
The mature graffian
First meiotic division is completed
Means this is when first polar body is made
How many follicles does woman have?
450,000
450 eggs are ovulated in a woman’s lifetime
Is a follicle vascularized?
No, because it is protected by a basement membrane
In the secondary follicle, what is going on?
- Theca folliculi differentiates into the following
a. Theca interna
-secretes androstenedione that transfers to follicular cells for testosterone production
-testosterone is converted to estradiol
b. Theca externa
-connective tissue capsule-like layer
-continuous with ovarian stroma
At this point, one follicle becomes dominant
What are the characteristics of Graafian follicles?
Completes the first meiotic division right before ovulation
Commences second meiotic division where it arrests in METAPHASE until fertilization
Fluid filled antrum (FA) is greatly enlarged and the oocyte (O2) is surrounded by the corona radiate (CR)
What is the corona radiatia?
Innermost layer of the cumulus oophorus
Directly adjacent to zona pellucida
Surrounds zona pellucida!!
Supplies vital proteins to the cell
What are the characteristics of atretic follicles?
Follicular atresia occurs at any point in the cycle
-both the oocyte and the granulosa cells are degenerating
in this case of early atresia
Follicular cells/oocytes die and are phagocytized
Occurs constantly but is maximal after birth, during puberty and during pregnancy
Where does fertilization take place?
Ampulla
What are the histologic characteristic of an atretic follicle?
-characterized by gross thickening of basement membrane between granulosa cells and the theca interna
Called a glassy membrane (GM)
What is the purpose of the corpus luteum?
Becomes a endocrine gland
Secretes progesterone
Granulosa and theca layers turn into granulosa lutein and theca lutein cells
Granulosa lutein secretes Prog and Estro
Theca lutein cells secrete Androstenedione and Prog
What is the purpose of progesterone?
PREVENTS further follicles from maturing
What is the corpus albicans?
Inactive fibrous tissue mass that forms following the involution of the corpus luteum
What are the three different parts of the oviduct (fallopian tube)?
- Infundibulum (closest to ovary)
- Ampulla
- Isthmus
- Interstitial part (closest to uterus)
What is the function of the epithelium of the ampulla?
Activates spermatozoa (capacitation)
Secretes nutrients for egg
Protects egg
Propells egg towards the uterus by ciliated cells
Are females with immotility syndrome (Kartagener’s syndrome) fertile? Significance?
Yes
Means females use smooth muscle rather than cilia for fertility
What are the three layers of the oviduct?
- mucosa (inner layer, contains cilia)
- muscularis (smooth mucle middle layer
- Serosa
What is tubal ectopic pregnancy?
When the fertilized ovum implants in the all of the oviduct
Tube bursts, bleeding in peritoneal cavity
What are the three layers of the uterus?
- Outer serosa/adventitia
- Myometrium
- smooth muscle bundles separated by connective tissue
- Endometrium (mucosa)
- consists of the epithelium and the LAMINA PROPRIA containing simple tubular glands
- functionalis and basalis
What is the internal os of the uterus?
The narrowing of the uterine cavity…right above cervix
What are the two layers of the endometrium?
- functionalis
2. basalis
What is the functionalis of endometrium?
Part of endometrium layer
-sloughed off during menstruation and replaced during each cycle
What is the basalis of endometrium?
Retained part of endometrium after menstruation and subsequently proliferates and provides a new epithelium and lamina propria
What are the 3 changes to the myometrium of the uterus during pregnancy?
- Hyperplasia
- Hypertrophy
- Increase in collagen
What is proliferative endometrium?
Stroma proliferates and glands extend to surface
Correlated with ESTROGEN release from developing follicles
What is secretive endometrium?
Marked by ovulation and production of glycogen-rich secretion
Correlated with PROGESTERONE release
What are changes in endometrium?
Proliferative and secretive
What are the layers of the vagina?
- Mucosa
- stratified squamous epithelium
- glycogen lamina propria
- loose connective tissue
- Muscular layer
- longitudinal bundles of smooth muscle
- Adventitia
- dense connective tissue rich in elastic fibers
Where does the mucus in vagina come from?
Comes from glands of uterine cervix
Vagina itself has NO GLANDS
What does the mammary gland look like at birth?
Short branching ducts with no alveoli
What does the mammary gland look like when nonpregnant?
Inactive duct system
What does mammary gland look like when during pregnancy
Alveoli proliferate at the ends of the ducts
Alveoli = spherical collections of epithelial cells that become active milk-secreting structures
What does mammary gland look like when lactating?
Milk secretion and accumulation in alveolar lumen
Plasma cell population increases around alveoli and is responsible for secretion of IgA
What produces the milk?
Produced by epithelial cells of the alveoli during lactation
What is milk made of?
- lipid droplets 4% of milk
2. membrane-limited vacuoles
What is tamoxifen?
An antagonist of the estrogen receptor in breast tissue
What is androstenedione?
Precursor to BOTH estrone (which estradiol and estrone)
AND
Testosterone
Converted by 17B-HSD
