Female reproductive system Flashcards
Main functions of the ovary
Production of female gametes
Secretion of female sex hormones
“Layers” of the ovary
Capsule (tunical albuginea) –> dense irregular CT and covered by cuboidal Surface
Stroma: loose CT
Parenchyma: Peithelial tissue
Structures in ovarian cortex
Follicles: primordial, Primary, secondary, tertiary Corpora lutea (remains of the follicle after Ovulation) Corpora albicantia (degenerated form of corpus luteum) Atretic follicles (Degeneration of follicles)
look at picture
Ovarian medulla
loose CT
Blood vessels
lmyphatic vessels
nerves
Stages of ovogenesis
I. Proliferation (mitotic divisions of oogonia)
II. Maturation (Meiosis of oocytes)
- Oogonia
- Primary oocyte
(first meiotic division pauses in Prophase by MIF and Ends before Ovulation) - Secondary oocyte and first polar Body
(second meiotid division stops during Metaphase and Ends during fertilization) - Matured oocyte and second polar body
Development of the ovaries
5-7th week: primordial germ cells into genital ridges
from 8th week: genital ridges form ovaries (no SRY)
Germ cells from oogonia
Folliculogenesis
- development of ovarian follicle from primordial to dominant
- all except preovulatory contain Primary oocytes
- Duration: several months
Primordial follicles
- next to capsule
- smallest
- oocyte is surrounded by layer of follicular cells
- every month: under influence of FSH: develop into secondary follicles
Primary follicles
- follicular cells become taller and mutliply into several layers –> GRANULAR LAYER
- ZONA PELLUCIDA between oocyte and follicular cells
- THECA FOLLICULI surrounding b.m. outside of granular layer
Theca folliculi
two layers
- theca interna (rounded endocrine cells)
- Theca externa (Spindle shaped, merge with stroma)
“two cells-two Hormones”
Theca interna cells produce androgens under LH
Androgens diffuse ino granulosa cells
Granulosa cells convert androgens to Estrogens under FSH
Secondary follicle
- small spaces between follicular cells filles with follicular fluids (Antrum- multiple)
Tertiary follicle
- bulges under ovarian Surface
- one follicular Antrum
- oocyte situated eccentrally in cumulus oophorus –> forms corona radiata
- just before Ovulation: Primary oocyte finished first meiotic division
Ovulation
- determined by sudden LH and FSH Peak on 14th day of cycle
- Mature follicle ruptures
- secondary oocyte surrounded by zona pellucida and corona radiata
Dominant follicle
during female cycle only one follicle matures and ovulates
the others degenerate and turn into atretic follicles
Atretic follicle
- process of follicular atresia may occur at any stage
- Primary oocyte degenerates
- remains of the follicle are phygocytoses and replaces by CT
Corpus luteum
- following Ovulation
- follicle collapses and fills with blood clot
- is a temporary endocrine gland
Luteinization
- cell of granulosa and theca interna differentiate into LUTEIN CELLS
- increase in size, fill with Lipid droplets
Types of Lutein cells
- Granulosa Lutein cells
- centrally located
- Lipid droplets, sER, mitochondria - Theca Lutein cells
- peripherally licated
- less droplets
Hormones coming from corpus luteum
under influence of LH: cells synthesize progesterone and Estrogens
Progesterone:
supresses FSH and LH
stimulates secretion of endometrial glands
Types of corpus luteum
- Of Menstruation
- when oocyte is not fertilized
- functions for 14 days
- degenerates and becomes corpus albicans - of pregnancy
- when oocyte is fertilized
- trophoblast secretes human chorionic gonadotropin
- functions for 3 months
- becomes corpus albicans
Luteolysis
- Degradation of curpus luteum
- due to decreased concentration of FHS and LH
- cells decrease in size and undergo apoptosis
- cells are phagocytosed
- becomes corpus albicans
Corpus albicans
dense irregular CT
forms temporary or permanent scar
Development of female genital tract
indifferent stage: wolffian and Müllerian ducts
from 8th week:
Müllerian duct: all female genital ducts
Uterine tube wall
mucosa:
- simple columnar
>ciliated cells (influenced by Estrogen)
>secretory cells (influenced by progesterone)
- lamina propria
Muscular layer:
- inner circular
- outer longitudinal
Serosa
Uterine wall
Mucosa/ endometrium - simple columnar >ciliated cells >secretory cells - lamina propria HAS TUBULAR GLANDS
Muscular layer/ myometrium
- inner longitudinal
- middle circular
- outer longitudinal
Serosa / Perimetrium (posterior) Anterior: adventitia
Layers of endometrium
Basal layer
Functional layer
a) spongy layer
b) compact layer
functional layer changes during menstrual cycle
Phases of the female menstrual cycle
Menstrual Phase(1-5 days) Proliferative Phase (6-14 days) -_> Estrogen Secretory Phase (15-28 days) --> progesterone
Proliferative Phase in uterus
Estrogen–> stroma and epitheloium Regenerates
- cells of Epithelium produce and store glycogen
- thickness of mucosa increases
Secreotry phase in uterus
progesterone –> epithelial cells actively secrete mucus
Glands become spiral
Thickness of mucosa increases
Menstrual Phase in uterus
- when corpus luteum degenerates (conc. of Estrogen and progesterone decreases)
- spasmodic contraction of spiral arteries of functional layer
- ischemia–> leakage of blood
- Endometrium is shed as menses
Uterine cervix
- mucosa contains branched tubular Glands
- simple columnar Epithelium
- Glands secrete mucus
- Mucosa lacks spiral arteries
- Portion that Projects into vagina: stratified suqmaous –> TRANSFORMATION ZONE
- METAPLASIA: Transformation of columnar cells into the stratified suqamous Epithelium
Vaginal wall
Mucosa:
- stratified squamous non-keratinized
- lamina propria
Muscular layer
- inner circular
- outer longitudinal
Adventitia
Changes in vaginal flora during the cycle
Midcycle: Epithelium is thick, Environment is acidic
During menstruations: Environment is alkaline because glycogen Levels decrease
