Reproductive system 3

Question 1

Regulation of male reproductive hormone

Answer 1

• GnRH stimulates secretion of LH and FSH from anterior pituitary
• LH stimulates testosterone secretion from Leydig Cells
• FSH stimulates Sertoli cells to increase spermatogenesis
• Testosterone stimulates Sertoli cells which develops reproductive organs

Question 2

Ovarian cycle

Answer 2

• Series of ovarian events that precede and follow oocyte maturation
• controls oogenesis

Question 3

Uterine cycle

Answer 3

• Preparation of uterus to receive ovum
• Mediated by reproductive hormones

Question 4

Stages of female reproductive cycle

Answer 4

• Menses first 2-4 days
• Proliferative phase (follicular phase) 4-15 days
• ## Luteal phase secretary phase 15-28 days

Question 5

Ovarian cycle

Answer 5

• During each ovarian cycle, up to 20 primordial follicles are activated to begin the maturation process only one reaches full maturity

Question 6

Stages ovarian cycle

Answer 6

• Follicular phase - development of Graafian follicle
• Ovulatory phase when there is a release of mature follicle
• Luteal phase - Formation of corpus luteum

Question 7

Endometrial cycle

Proliferative phase

Answer 7

• where secondary follical maturation
• Granulosa secreate oestrogen
• Causig epithelial cells of endometrium to divide rapidly causing endometrium to thicken

Question 8

Testosterone has negative impacts

Answer 8

• Effect on hypothalmus and pituitary causing sertoli cells to secrete inhibin increase in levels

Question 9

Endometrial cycle

Secretory (Luteal) phase

Answer 9

• Secrete progesterone and smaller amounts of oestrogen
• Progesterone causes the cells of the endometrium to become larger and to secrete a small amount of fluid
• Full development of endometrium
• If no fertilisation then corpus luteum degenerates and progesterone drops

Question 10

Hormonal control of the
female reproductive
cycle

Answer 10

• GnRH stimulates the secreation of LH and FSH from anterior pituitary gland
• Fast GnRH pulse causes LH synthesis and secreation
• Slow GnRH pulse causes FSH secreation
• LH stimulates overies to develop and the production of androgen/theca cells
• FSH effects growth of follicles which convert androgens to oestrogens in granulosa
• Triggers ovulation and prodution of corpus luteum

Question 11

Oestrogen positive feedback

Answer 11

• Resulting in increased LH and FSH secretion

Question 12

Negative feedback of oestrogen

Answer 12

With progesterone on the hypothalamus and anterior
pituitary after ovulation, resulting in decreased LH and FSH secretion

Question 13

Negative feedback of progesterone

Answer 13

• with oestrogen on the hypothalamus and anterior
  pituitary after ovulation, resulting in decreased LH and FSH secretion

Question 14

Follicular Phase

Answer 14

• Oestrogen stimulates GnRH secretion from
  hypothalamus
• GnRH triggers FSH and LH
• FSH stimulates oestrogen secretion at an increasing rate
  from the developing follicles.
• This positive-feedback loop produces a series of larger and
  larger surges of FSH and LH secretion

Question 15

Ovulation

Answer 15

• Ovulation occurs in response to the large increases in LH levels
• About day 14 of the menstrual cycle
• This large increase in LH is development of the corpus luteum

Question 16

Luteal Phase

Answer 16

• Corpus luteum begins to secrete progesterone and
  oestrogen
• Progesterone cells of the endometrium to become larger

Question 17

Negative feedback of the luteal phase

Answer 17

• Progesterone and oestrogen act on the hypothalamus and anterior pituitary gland to inhibit GnRH, LH, and FSH
  secretion
• Follicles are not stimulated LH and FSH levels decline
• Corpus luteum degenerates causing lower progesterone

Question 18

Menses

Answer 18

• Oestrogen and progesterone
  secretion is low
• decrease progesterone levels, the endometrial lining of the uterus sloughs off, resulting in menses
• The rate of LH remains low, and the rate of FSH secretion
  increases as progesterone levels decline
• Stimulates follical stimulation to start releasing oestrogen

Question 19

Fertilisation

Answer 19

• hCG from pituitary and later placenta maintains corpus luteum
• Oestrogen and progesterone levels maintained
• Subsequently Placenta takes over progesterone and oestrogen
  production

Question 20

Contraception

Answer 20

• Combined pill containing oestrogen and progesterone oral contraceptive
• Generally they reduce LH and FSH release from the anterior pituitary.
• Oestrogen and progesterone are present in high enough concentrations to have a negative-feedback effect on the pituitary

Question 21

Mini-pill

Answer 21

• Contains only synthetic progesterone which reduces and thickens the mucus of the cervix
• Prevents sperm cells from reaching the oocyte