Chapter 28: Folliculogenesis

Question 1

What is folliculogenesis?

Answer 1

The process that follicles in the ovary go through as an egg undergoes oogenesis

Question 2

What are the 5 stages of folliculogenesis?

Answer 2

primordial follicles
primary follicles
secondary follicles
tertiary follicles
mature follicles

Question 3

Primordial follicles

Answer 3

They are concentrated in the ovarian cortex close to the capsule. They all form in the 6-9 month of gestation. In the adult ovary 90-95% of the follicles are primordial. Those that survive childhood atresia wait at least 13 years-50 years before they are reactivated

Question 4

What is the recruitment of primordial follicles?

Answer 4

the process that awakens about 2 dozen primordial follicles each month to begin a 290 day march to maturity; usually only one of these eggs eventually ovulates and the rest dies

Question 5

Primary follicles

Answer 5

about 140 days into the cycle (recruitment) primordial follicles have become primary follicles. The development from primordial to primary follicle is controlled by paracrine growth factors and not gonadotropins because they still dont have receptors for FSH or LH.

they are cuboidal cells a this point

Question 6

Secondary follicles

Answer 6

these appear about 170 days into the cycle, still about six menstrual cycles before ovulation. They are distinguished by follicular cells that have multiplied and piled atop each other to form two or more layers and are now called granulosa cells

Question 7

What is zona pellucida?

Answer 7

a layer of glycoprotein gel that surrounds the oocyte in the secondary follicle stage

Question 8

tertiary follicles

Answer 8

about 60 days before ovulation, the granulosa cells begin secreting follicular fluid

Question 9

Antrum

Answer 9

as tertiary follicles enlarge, the pools marge and become a single fluid filled cavity called th antrum

Question 10

What are tertiary and mature follicles called?

Answer 10

antral follicles

Question 11

What are follicles called before the last two phases?

Answer 11

preantral

Question 12

Corona radiata

Answer 12

the innermost layer of cells of the cumulus, surrounding the zona pellucida and oocyte

Question 13

cumulus oophorus

Answer 13

on one side of the antrum, a mound of granulosa cells covers the oocyte and secures it to the follicle wall

Question 14

Mature follicles

Answer 14

normally only one follicle in each month’s cohort becomes a mature follicle destined to ovulate while the rest degenerate

Question 15

Preovulatory follicle

Answer 15

day 5 before ovulation when the follicle grows to 20 mm in diameter. it attains an astonishing size up to 30mm by the time of ovulation.