Topic 17 -Female Reproductive system Flashcards
gonads=ovaries
located?
located in pelvic cavity on lateral sides of uterus
histology of ovaries
4 layers
a) ovarian mesothelium - surface epithelium
b) tunica albuginea - CT
c) ovarian cortex - contains ovarian follicles + CT follicles = layers of cells surrounding immature egg (support + protect)
d) ovarian medulla - blood + lymph vessels, nerves, CT
how are the ovaries held in place
a) ovarian ligament - to uterus
b) suspensory ligament - to pelvic wall
c) mesovarium - superior membrane
NOTE: suspensory ligament + mesovarium = parts of broad ligament = parietal peritoneum
3 sections of the Uterine (Fallopian) Tubes
a) infundibulum -suspended over ovary
- has finger-like projections= fimbriae
b) ampulla = middle - fertilization occurs here
c) isthmus - connects to uterus
histology of Fallopian tubes
a) mucosa - simple columnar epithelium with cilia or microvilli
- moves oocyte or cell mass along tube
- secretes nutrient fluid
b) muscularis externa - smooth muscle - helps movement
c) serosa - visceral peritoneum
Uterus 3 parts
a) fundus - above level of uterine tubes
b) body - main portion
- space within = uterine cavity
c) cervix - inferior, narrow portion - opens into vagina
supportive membranes (attach uterus to abdominal wall)
a) broad ligaments - peritoneum
b) round ligaments - fibrous CT - attach uterus to anterior body wall
c) uterosacral ligaments
- peritoneum - attach to sacrum
histology of uterus
a) perimetrium - outer layer
- visceral peritoneum
b) myometrium - 3 layers of smooth muscle (muscularis externa)
c) endometrium - mucous membrane
- contains endometrial glands – secrete a nutritive fluid
2 layers of the endometrium
i) stratum functionalis - faces uterine cavity
- shed monthly (menstruation)
ii) stratum basalis
- permanent
- undergoes mitosis to replace functionalis
Vagina
birth canal, passageway for sperm + menstrual flow
Vagina histology
a) mucosa - stratified squamous epithelium - rugae
b) muscularis externa
- 2 layers of smooth muscle
c) adventitia - fibroelastic CT - no serosa
Female Oogenesis
Oogonia (2n) (mitosis) -> many oogonia (differentiate) -> 1⁰ oocyte (2n) (meiosis 1) -> 1st polar body (n) AND 2⁰ oocyte (n) (ovulated) -> if fertilized, meiosis 2 gives 1 ovum (n) and 2nd polar body (n)
1 1⁰ oocyte forms
1 ovum and 2 or 4 polar bodies
polar bodies=
discarded nuclear material
how many oogonia in a 6 month fetus
5 million
how many 1⁰ oocytes (2n) at birth
when do they enter meiosis 1? arrest?
1 million (no oogonia)
enter before birth, arrest in prophase 1
at puberty how many oocytes remain?
what stimulates completion of meiosis 1?
400, 000
LH (luteinizing hormone) stimulates completion of meiosis I
what does the 2⁰ oocyte (n) do?
begins meiosis II and arrests in metaphase II
- this is ovulated (usually 1/month)
- ~ 500 ovulated from puberty to menopause
what are the follicle stages
Primordial follicle Primary follicle Secondary follicle Vesicular follicle Corpus luteum Corpus albicans
Primordial follicle
- in ovary at birth
- 1⁰ oocyte surrounded by a single layer of flat cells
Primary follicle
-single layer become cuboidal – cells now called granulosa cells
- granulosa cells proliferate (become stratified) - secrete zona pellucida around oocyte
- theca cells (endocrine) form from surrounding tissue
can reach this stage any time from before birth to menopause
Secondary follicle
- at puberty, ovarian cycles begin
- under influence of rising FSH: - granulosa cells proliferate more and start to secrete fluid (accumulates between cells)
Vesicular follicle
- on surface of ovary
- fluid filled spaces unite into single large antrum
- granulosa cells that still surround oocyte = corona radiate
continues secreting estrogen - estrogen triggers release of luteinizing hormone (LH) causing:
a) completion of meiosis I - enters meiosis II and arrests in metaphase II
b) ovulation – release of 2⁰ oocyte from follicle into peritoneal cavity
corpus luteum
- follicle that remains after ovulation
- produces high levels of estrogen and progesterone to support fetal development
- if no pregnancy, degenerates into corpus albicans
