Female reproductive processes

Question 1

what are three difefrences between spermogenesis and oogenesis?

Answer 1

life limit (F= limited, M-limited)

continunity (F= interrupted meiosis, M= continious meiosus)

division (F= asymmetric division (1) M= symmertical (4)

Question 2

Describe the role of Cohesins in Meiotic arrestand increasubf tisk of down syndrome

Answer 2

they keep sister chromatids together

Weaken with increase in maternal age

= incorrect microtubule=centromere attachment

= chromosome segregation erros (nondisjunction) in metapahse and anaphase I

Question 3

What is the first follicle of Follicle development? Structure?

Answer 3

Primordial follicle

Oocyte surrounded by single layer of ill-defined squamous-like follicle cells

Question 4

What is the second follicle of Follicle development and how is it formed?

Answer 4

primary follicle

Differentiation –> single layer of cuboidal/ columnar type follicle cells surrounding oocyte

Question 5

What is the third follicle of Follicle development? Structure?

Answer 5

Secondary follicle
Two or more layers of stratified granulosa cells surround oocyte

Question 6

What is the fourth follicle of Follicle development? Structure?

Answer 6

Late secondary follicle

Fluid-filled spaces between granulosa cells appear

Thecal cells and zona become visible

Question 7

What is the fifth follicle of Follicle development? Structure?

Answer 7

Tertiary follicle

Central fluid filled cavity forms

Corona radiata (cumulus cells) Ooccyte

Question 8

What is the sixth follicle of Follicle development? Structure?

Answer 8

ovulating follicle

Follicle ruptures

Oocyte ovulated with cumulus cells

Question 9

How is the seventh element of follicle development formed and what is its function?

Answer 9

Corpus luteum

Residual follicle forms corpus luteum

Secretes hormones that maintain pregnancy

Question 10

What is the 8th step of follicle development?

Answer 10

Corpora albicantia

Widespread cell death

Leaves scar tissues

Question 11

What are the hormones involved in the Ovarian cycle and what are their functions?

Answer 11

GnRH: release of LH and FSH

LH: stimulates secretion of androgens

FSH: supports conversion of androgens –> estrogens

Osetrogen: negatively/pos regulation of GnRH, LH and FSH. Stimulates endometrium and pri/sec sex characteristics.

Inhibin: inhibits FSH

Progesterone: negative regulation of GnRH, LH and FSH, Stimulates endometrium and pri/sec sex characteristics.

Question 12

What are the two main phases of the ovarian cycle and when do they occur?

Answer 12

Folllicular (1-14)
Luteal (15-28)

Question 13

What occurs in the follicular stage before puberty?

Answer 13

primordial follicles spontaneously activate

Question 14

What are the steps in oogensis?

Answer 14

1. oogonium → primary oocytes (before birth) by mitosis
2. primary oocyte arrested in prophase I
3. completes meiosis I in response to LH surge → secondary oocyte and 1st polar body
4. secondary oocyte is arrested in metaphase II
5. ovulation of the secondary oocyte
6. completes meiosis II in response to fertilisation → ovum and 2nd polar body

Question 14

What occurs in the follicular phase after puberty? What are the changes in hormones?

Answer 14

growth of secondary follicles accelerated by FSH and LH

Growth follicles (due to increase estrogen/inhibin and decrease in FSH)

Question 15

What are the preantral and antral follicle types?

Answer 15

preantral
= Primordial follicle, primary follicle, secondary follicle and late secondary follicle

antral
= tertiary antral and Graafian (amture vesicualr follicle)

Question 16

In a regular cycle, when does ovulation occur?

Answer 16

14 dats after mensturation

Question 17

Hormones of ovulation

Answer 17

Elevated estrogen = forms dominant follicle

Triggers LH surge = resumes meiosis in metaphase II, final growth of follcile wall and ovulation.

afterwards: oestrgen declines

Question 18

What are the three layers of the uterus and their function?

Answer 18

Perimetrium

Myometrium – bulky contractile smooth muscle

Endometrium- startum functionalis (sheds) and stratum basalis (rebuilds finctional layer)

Question 20

What is the function of the uterine cycle and how long does it take?

Answer 20

prepare uterus to receive fertilized embryo after ovulation.

average = 29.5 days
shorter as age

Question 21

what are the three phases of the uterine cycle and when do they occur?

Answer 21

Menstrual

Days 1-5

Proliferative

6-14

Secretory

15-28

Question 22

What occurs in each of the three phases of the uterine cycle?

Answer 22

Menstrual – destructive phase
-Shedding of functional endometrium layer

Proliferative – follicular, oestrogenic
-Rebuilding functional layer

Secretory – luteal, pregestational
-Enrichment of blood supply and nutrient secretion of endometrial glands

Question 23

Describe the events of the shedding of the functional endometrium.

Answer 23

Uterine arteries extend branches into uterine wall

Arcuate arteries of myometrium send branches into endometrium= straight arteries in basal, spiral in functional.

Degenerating functional layer fragments and sloughs off.

Question 24

Is there more progestrone or estrogen in the luteal phase and what is the impact of this?

Answer 24

Luteinized granulosa cells secretes more progesterone than estrogen = decrease in FSH and LH = pause on folliculogenesis progesterone = dominant – singles ovulation occurs and makes endometrium receptive to implantation.

Question 25

Steps of luteal phase

Answer 25

Ovulation ends LH stimulates granulosa and theca cells differentiate into large and small luteal cells (respectively) = corpus luteum Luteinized granulosa cells secretes more progesterone than estrogen = decrease in FSH and LH = pause on folliculogenesis. Inhibin also inhibits FSH Estrogen declines and progesterone = dominant – singles ovulation occurs and makes endometrium receptive to implantation.

Question 26

compare CL in pregnant and non-pregnant cycles.

Answer 26

Non-Pregnant Cycle: The corpus luteum degenerates if pregnancy does not occur, leading to a decrease in progesterone and estrogen and the start of menstruation. LH initally supports it. Pregnant Cycle: The corpus luteum is maintained by hCG and continues to produce PE and E to maintain endometrial lining.

Question 27

compare the ovarian cycle w the uterine cycle

Answer 27

The ovarian cycle = changes that occur in the follicles of the ovary, uterine cycle = changes in the endometrial lining of the uterus. ovarian -follicular and luteal uterine -menstural -prolifertive -secretory