lecture1

Question 1

name the three uterine phases and describe the endometrium changes in each phase. stating which day makes up each phase

Answer 1

menstrual flow- shedding of the endometrium, day 1-5
proliferative- growth of the endometrium, day 5-13
secretory- maintanance of endometrium, day 14-28

Question 2

name the 4 ovarian phases and the ovarian changes, stating which days make up each phase

Answer 2

menstrual phase- recruitment of many follicles, day 1-5
folicular phase- maturation of the follicle, day 5-13
ovulation phase- oocyte is released from dominant follicle, day 14
luteal phase- corpus luteum forms from the follicle, day 15-28

Question 3

describe the hypothalamo-pituitary-gonadal axis from hypothalamus to when oestrogen is secreted

Answer 3

hypothalamus
V
gonadotropin releasing hormone (GnRH)
V
anterior pituitary
          V
FSH   &   LH
          V
gonads
    V
oestrogen, progesterone or testosterone

Question 4

what is the relationship between FSH and oestrogen

Answer 4

FSH binds to granulosa cells of the follicle, converting androgen to oestrogen. so FSH increases oestrogen

Question 5

which receptor cells do FSH and LH bind to on the follicle respectively for the secretion of oestrogen

Answer 5

FSH- granulosa cells of the follicle

LH- theca cells of the follicle

Question 6

match:
A)increasing oestrogen 1) positive feedback-
increased LH/FSH ratio
B)high oestrogen 2)negative feedback-
decreased LH/FSH ratio

Answer 6

A—–2

B—–1

Question 7

which hormone stimulates ovulation and what happens to the remaing part of the follicle after the oocyte is released

Answer 7

lutenising hormone LH. the remaing part forms the corpus luteum

Question 8

which hormone does the corpus luteum secrete

Answer 8

progesterone

Question 9

which hormone decrease causes shredding(loss) of the endometrium? (hint: the hormone that maintains the endometrium)

Answer 9

progesterone decrease

Question 10

what is the window for fertilisation

Answer 10

3days before ovulation to 24hours after ovulation.

the sperm can live for 72hours(3 days) and oocyte for 24 hours (1day)

Question 11

what is the acrosomal reaction and where does it occur

Answer 11

when the spermatozoa penetrates the oocyte and it occurs at the zona pellucida of the oocyte.

Question 12

what 2 ways ensure monospermy

Answer 12

fast block to polyspermy- membrane depolarisation to prevent other sperm from fusing with the oocyte membrane
slow block to polyspermy-zonal inhibiting proteins; they destroy sperm receptors on the oocyte and cause sperm already bound to receptors to detach.

Question 13

what are the three types of contraception

Answer 13

1. blockage of sperm transport to the ovum
2. prevention of ovulation
3. blockage of implantation