Female Histology 2

Question 1

What is the proces off follicle development in the cortex?

Answer 1

• Early development under control of FSH
• Follicular cells produce estrogens
  
  • cause anterior pituitary to release LH
  • stimulates ovulation
• Process of ovulation
  
  • primordial follicle
  • primary follicle
  • secondary follicle
  • mature (Graafian) follicle

Question 2

Describe the histology of the primordial follicle.

Answer 2

primary oocyte with a single layer of squamous follicular cells on a basal lamina

Question 3

Describe the histology of the primary follicle.

Answer 3

• Development of three layers:
  
  • Stratum granulosum - follicular cells form a stratified cuboidal sheath
  • Zona pellucida - made up of interdigitations between oocyte membrane and follicular cells
  • Theca folliculi - a layer of stromal cells that develop outside the basement membrane

Question 4

Describe the histology of the secondary follicle.

Answer 4

• Antrum appears - fluid-filled (liquor folliculi) cavity in the stratum granulosum
• Theca develops two layers:
  
  • Theca externa - connective tissue and vascular
  • Theca interna - endocrine functions
    
    • Produces estrogen in conjunction with granulose cells
    • Site of estrogen entry into the bloodstream

Question 5

Describe the histology of the mature (Graafian) follicle.

Answer 5

• Antrum enlarges and the oocyte is large, near surface of follicle
• Granulosa cells surrounding the oocyte are called the cumulus oophorus
• Innermost cumulus cells form a columnar layer - corona radiata

Question 6

Describe the process of oocyte maturation.

Answer 6

• Oocytes develop from the wall of the embryonic gut
• Most primary oocytes are lost through involution/degeneration - called atresia
  
  • can occur during any stage of follicular development
  • About 400,000 primordial follicles present at birth
  • Rate of loss increases at birth, puberty, and pregnancy
• First meiotic divisions begin before birth - arrested in prophase
  
  • continues after puberty
  • completed in mature follicle
  • results in a secondary oocyte and first polar body
• Second meiotic division just before ovulation, stops at metaphase - not completed until fertilization

Question 7

What is ovulation?

Answer 7

The rupture of the follicle at the surface of the ovary, releasing the secondary oocyte, corona radiata, and other cumulus cells.

Question 8

What are the major hormone regulators of follicle development and oocytematuration/ovulation?

Answer 8

• Early development - under control of FSH
• Ovulation - stimulated by LH after folluclar cells produce estrogen (stimulates anterior pituitary production)