Female Histology 4

Question 1

What are the four parts of the uterine tubes?

Answer 1

• Intramural segment - in uterine wall
• Isthmus - narrow segment close to uterus
• Dilated ampulla - found in distal half of tube
• Infundibulum - terminal, funnel-shaped portion with finger-like fimbriae

Question 2

Describe the histology of the uterine tubes.

Answer 2

• Mucosa - longitudinal folds that are numerous and complicated in ampulla, smaller closer to uterus
  
  • lined by simple columnar epithelium
  • ciliated and non-ciliated secretory cells
  • ciliated cells increase in resposne to estrogen
• Lamina propria - loose C.T.
• Muscularis - interlacing smooth muscle
  
  • thicker (with smaller lumen) closer to uterus

Question 3

Describe the histology of the uterine wall.

Answer 3

• Endometrium - mucosa, decidua
  
  • surface is simple columnar epithelium
  • mixture of ciliated and non-ciliated secretory cells
  • simple tubular glands
  • lamina propria - highly cellular C.T.
  • Two layers:
    
    • stratum functionale - more superficial layer sloughed off and rebuilt during menstrual cycle
    • stratum basale - deeper layer retained
• Myometrium - muscularis
  
  • three ill-defined layers of smooth muscle
  • larger blood vessels are in the middle layer - stratum vasculare
  • Cervix differs from the body, has bout 50% connective tissue
• Serosa - mesothelium, visceral peritoneum
  
  • continuous with broad ligament
  • mesentery extends transversely across pelvic floor

Question 4

List the phases of the menstrual cycle.

Answer 4

• proliferative phase
• secretory phase
• menstrual phase
• gravid cycle

Question 5

Describe the histological changes of the proliferative phase.

Answer 5

• Endometrium thickens 2-3 times from what remains at the end of the menstrual phase
• Glands are longer and more numerous
• Coiled arteries lengthen

Question 6

Describe the histological changes of the secretory phase.

Answer 6

• 1-2 days after ovulation
• glands become coiled and sacculated and secrete glycogen-rich fluid
• thickness twice that of proliferative phase

Question 7

Describe the histological changes of the menstrual phase.

Answer 7

• Five days before menstruation
• Hormonal activity of corpus luteum reduced if no pregnancy
• Glands of stratum functionale stop secreting and tissue becomes ischemic because of intermittent constriction of spiral arteries
• Blood and sloughed-off mucosa discharged via the vagina

Question 8

Endometriosis

Answer 8

• The abnormal discharge of endometrium through the uterine tubes into the peritoneal cavity
• Tissue adheres to peritoneum
• Results in painful swelling as the cells respond to the hormonal changes in the menstrual cycle

Question 9

Gravid cycle (pregnancy)

Answer 9

• Fertilized ovum develops into blastocyst by day 5
• Implants in the endometrium
• Chorion of blastocyst (and later syncytiotrophoblast of placental villus) secretes HCG
  
  • maintains corpus luteum
  • in turn corpus luteum maintains stratum functionalis of the endometrium

Question 10

Describe the histological changes of the cervix during the menstrual cycle.

Answer 10

• Mucosa contains extensively branched cervical glands
• Different from simply tubular glands in the body of the uterus
• Cervix changes little during menstrual cycle

Question 11

Describe the hormonal regulation of the menstrual cycle.

Answer 11

• Estrogen/follicular phase - first two weeks, leads up to ovulation
  
  • occupied by follicle development and proliferative phase of endometrium
• Progesterone/luteal phase - second two weeks of menstrual cycle
  
  • occurs with continued estrogen secretion
  • prepares the uterus for pregnancy
  • progesterone from corpus luteum promotes secretory phase of the endometrium
• HCG produced with pregnancy, maintains the corpus luteum
  
  • in turn maintains the endometrium for pregnancs
• Without HCG, progesterone blocks action of luteinizing hormone
  
  • corpus luteum “kills itself”
  • secretory glands of the endometrium degenerate
  • spiral arteries constrict
  • menstrual phase of endometrium begins

Question 12

Describe the mechanism of hormone production in the menstrual cycle.

Answer 12

anterior pituitary → FSH → follicle development and estrogen secretion → LH surge from anterior pituitary → ovulation and maintenance of corpus luteum → progesterone secretion by corpus luteum