Week 1: Uterus, cervix, vagina MA

Question 1

Tissue layers of uterus and their function

Answer 1

1. Perimetrium: serosa
2. Myometrium: thickest layer. 3 SM layers. Contraction stimulated by oxytocin and prostaglandins.
3. Endometrium: mucosal layer
   - lumenal surface covered by simple columnar epithelium, w/ secretory and ciliated cells
   - stratum functionalis: temporary layer that thickens in response to steroids and is shed mostly.
   - stratum basalis: permanent layer.
   - glands present. Spiral artery through basalis, towards the top forms venous lakes

Question 2

Endometrial changes during menstrual cycle: proliferative phase

Answer 2

• mid follicular cycle
• estrogen causes stratum functionalis to regenerate
• extensive mitosis of stromal and epithelial cells. Hypertrophy and hyperplasia of glandular epithelial cells.
• increased blood flow, edema
• glycogen accumulates in epithelial cells

Question 3

Endometrial changes during menstrual cycle: Secretory phase (luteal)

Answer 3

• sawtooth appearance of endometrium
• progesterone causes glands to become tortuous and helical arteries to coil
• stromal cells enlarge in number and size.
• secretory products accumulate in glands
• basal vacuolation: glycogen in glandular epithelium forms vacuoles in basal aspect. Later shift to lumenal
• veins dilate, form venous lakes
• endometrium thickens to 5-6 mm

Question 4

Endometrial changes during menstrual cycle: Premenstrual phase

Answer 4

• final days of secretory phase
• coiled arteries constrict periodically at base
• decrease in blood flow cases discharge and collapse of glands
• shrinkage of endometrium
• leukocytes accumulate

Question 5

Endometrial changes during menstrual cycle: menstrual phase

Answer 5

• day 1-5 early follicular phase. Progesterone falls as corpus luteum degenerates
• functionalis is desquamated
• lamina propria has extravasated blood
• intermittent constriction of coiled arteries leads to breaks in arteries
• degenerating blood soaked functionalism is sloughed off

Question 6

Cervix: micro

Answer 6

• composed of mostly connective tissue
• towards the uterus: tall columnar epithelium, highly branched glands. Mucous secretory cells, when plugged form Nabothian cysts
• muscularis: cervical myometrium has some SM, but more CT
• towards the vagina-portio vaginalis: stratified squamous

Question 7

Cervical mucus

Answer 7

• under estrogen: increases in volume and elasticity until ovulation. allows sperm passage.
• luteal phase: mucus is minimal and viscous, sperm can’t pass.
• quality of mucus judged by spinnbarkeit or ferning

Question 8

Vagina: micro

Answer 8

• mucosa: stratified sq. epi. Rich in glycogen. Lack glands. few nerve endings. lactobacillus metabolism of glycogen creates low pH, fends off infection. Fluid during arousal from extravasation from capillaries
• mucscularis: longitudinal SM, some circular near mucosa
• adventitia: DCT rich in elastic fibers.