Female Anatomy/Histology

Question 1

Basic Components of Ovaries

Answer 1

• Cortex (outer) - dense connective tissue w/ follicles embedded
• Medulla (inner) - contains vessels, lymphatics, connective tissue
• Lined by germinal epithelium (simple cuboidal epithelium)

Question 2

Primordial Follicles

Answer 2

• primary oocyte in late prophase I in meiosis (chiasmata crossover pts)
• ring of pre-granulosa cells around it (simple squamous w/ gap junctions)

Question 3

Pre-Antral Follicles

Answer 3

• still primary oocyte but cytoplasm enlarges
• zona pellucida outside oocyte that acts as sperm receptor and prevents implantation at this stage
• next outside layer is granulosa cells (cuboidal; in single or multiple layers)
  
  • Primary pre-antral - sngl layer granulosa cells
  • Secondary pre-antral - multiple layers of granulosa cells
• surrounded by basement membrane
• theca cells outside BM

Question 4

Antral Follicles

Answer 4

• still primary oocyte w/ zona pellucida
• development of antrum (requires FSH)
• granulosa cells around oocyte (corona radiata) bind FSH
• now 2 layers of theca cells
  
  • 1- Theca Interna - binds LH to synthesize androgens; these diffuse into granulosa cells which convert to estradiol
  • 2- Theca Externa - smooth muscle like to squeeze follicle out in ovulation

Question 5

Graafian Follicles

Answer 5

• requires LH surge - stimulates production of collagenase (thins roof and breaks thru germinal epithelium/ stroma and cuts cumulus oopherus stalk to free the oocyte)
  
  • Oocyte now floating in antrum fluid
• now secondary oocyte (metaphase of meiosis II)
• huge inc in antrum size
• peak estrogen production by granulosa cells

Question 6

Corpus Luteum

Answer 6

• Under high LH stimulation –> morph change –> corpus luteum (lasts ~14 days)
• Granulosa lutein cells (plump) - cont to secrete estrogens and now secrete progesterone
• Theca lutein cells (dense)- still under LH control and still make androgens; invade corpus luteum

Question 7

Fallopian Tubes

Answer 7

• Role: fertilization & transport of conceptus to uterus
• Structures
  
  • 1- Infundibulum - open end w/ fimbriae to pick up oocyte
  • 2- Ampulla - most folding
  • 3- Isthmus - narrow
  • 4- Intramural - thru uterine wall; fuses w/ myometrium
• Layers of Wall
  
  • Serosa
  • Muscularis - peristalsis to drive to uterus; inner circular and outer longitudinal layers
  • Mucosa - highly folded; simple columnar w/ cilia (for movement) and peg cells for nutritional support of sperm (both columnar and peg cells inc w/ inc estrogen)

Question 8

Main Components of the Uterus

Answer 8

• Myometrium - muscle; hypertrophy and hyperplasia of wall for labor; smooth muscle that runs in multiple directions
• Endometrium - from epithelium
  • 1- Basalis - stays behind at menses for progenitor cells of next round
  • 2- Functionalis - responds to estrogen / progesterone; shed

Question 9

Main Components of the Cervix

Answer 9

• Endocervix - branched glands; simple columnar; enlarges w/ estrogen
• Ectocervix - no glands; just transitions to stratified squamous to withstand acidic vagina
• Myometrium - made of 85% collagen 1 (strong); keeps fluid and embryo inside in pregnancy; collagenases released prior to labor to break some down

Question 10

Cervical Secretions

Answer 10

• When high estrogen - alkaline mucous to support transport of sperm up
• When high progesterone / less estrogen - viscous, acidic plug to block other viruses, bacteria, sperm from entering

Question 11

Vagina Histology

Answer 11

• Muscular tube of stratified squamous epithelium w/o glands (lubrication comes from cervix)
• Stores glycogen (clear on H&E) for lactobacilli nutrition; maintain ow pH via lactic acid to maintain vaginal flora
• Both circular and longitudinal muscle layers