two cell theory part 2

Question 1

at what stage are gametes at birth

Answer 1

primary oocyte (in primordial follicle)

Question 2

what are the 3 follicle cell types

Answer 2

1.oocytes
2. granulosa cells (follicular)
3. thecal cells

Question 3

what is the progression of follicle maturation in initial recruitment (preantral phase)

Answer 3

oogonia -> primordial -> primary -> secondaryw

Question 4

what is the progression of follicle maturation in cyclic recruitment (antral phase)

Answer 4

tertiary -> preovulatory

Question 5

what hormone is cyclic recruitment dependent on

Answer 5

FSH

Question 6

what does the primordial follicle contain

Answer 6

-primary oocytes arrested in prophase I of meiosis
-oocytes surrounded by flattened granulosa cells

Question 7

how is the primary follicle changed

Answer 7

-oocyte enlarges
-layer of granulosa cells gets larger, cuboid, then starts to divide
-zona pellucida appears
-first see FSH receptors

Question 8

how is the secondary follicle changed

Answer 8

-granulosa cells continue to divide: 2-6 cell layers
-theca cells now present

Question 9

what is the role of FSH

Answer 9

important to transition from secondary to tertiary follicles

Question 10

are any hormones needed from the progression of primordial follicles to secondary follicles

Answer 10

no, FSH-independent

Question 11

how does FSH affect granulosa cells

Answer 11

divide; more granulosa cells = bigger follicles

Question 12

what does a tertiary follicle look like/contain

Answer 12

-presence of antrum
-late (large follicle): progress from primary oocyte to secondary oocyte

Question 13

what stage is a gamete in a graafian follicle

Answer 13

secondary oocyte (what gets ovulated)

Question 14

if an ovary-having individual has a reproductive window of 40 years, and only ovulates one oocyte per month, how many follicles do they lose?

Answer 14

12 x 40 = 480

Question 15

what is atresia

Answer 15

-coordinated apoptosis

-as follicles mature, there are some that stop and whose cells undergo apoptosis
-can occur at any stage of follicular growth

Question 16

what does inner theca cells respond to

Answer 16

-LH
-LH starts cAMP cascade
-major outcome: androstenedione

Question 17

what does granulosa cells respond to

Answer 17

-respond to FSH by increasing cAMP levels
-have FSH receptors

Question 18

where do we find aromatase

Answer 18

granulosa cells, inner theca cells, oocytes

Question 19

does FSH cause aromatase expression

Answer 19

no in the example, shows that aromatase shows up in granulosa cells

but overall, FSH does drive up aromatase expression

Question 20

how does aromatase get produced

Answer 20

-granulosa cells respond to FSH which causes cAMP cascade and leads to production of aromatase
-converts androstenedione from theca cells into estradiol

Question 21

what causes LH receptor expression in granulosa cells

Answer 21

estradiol which expresses LH receptors

Question 22

what is luteinization

Answer 22

FSH produces estradiol, increased estradiol causes granulosa cell production which expresses LH receptors and also makes progesterone production. they are now called luteal cells because they produce progesterone

Question 23

what does the presence of LH receptors cause

Answer 23

leads to cascade that starts expression of enzymes that produce progesterone

Question 24

why didn’t the granulosa cell make progesterone before it was stimulated by LH

Answer 24

they do not yet express the enzymes that convert cholesterol to progesterone

Question 25

why didnt the granulosa cells start expressing LH receptors earlier

Answer 25

-don’t have many LH receptor expressing luteal cells earlier because not sufficient estrogen in circulation
-not enough estrogen because the major source of estradiol in the body comes from granulosa cells, stimulated by FSH

Question 26

IHH (idiopathic hypogonadotropic hypogonadism)

Answer 26

-have significantly less sex steroids in circulation
-have smaller gonads
-do not hit puberty
-are infertile