Ovarian cycle

Question 1

label the image of the ovarian cycle

Answer 1

USE IPAD TO INSERT

Question 2

menstrual cycle

Answer 2

cyclical change in fertility

Question 3

ovarian cycle

Answer 3

cylcical endocrine changes

Question 4

endometrial cycle

Answer 4

preparing the female reproductive tract

Question 5

what do the ovarian cycle and endometrial cylce prepare for

Answer 5

1. transport of spermatozoa and fertilisaiton in the follicular phase
2. supporting implantation and subsequent development of embryo during luteal phase

Question 6

oestrogen dominant part

Answer 6

follicular phase

Question 7

progesterone dominant phase

Answer 7

luteal phase

Question 8

phases of follicular development

Answer 8

preantral
antral
pre-ovulatory

Question 9

preantral phase

Answer 9

gonadotrophin independent
77-85 days

proliferation granulosa cells
increase oocyte size and synthetic activity
oocyte secretes zona pellucida
cytoplasmic processes between granulosa cells and oocute
development of theca cell layers and blood supply

Question 10

antral phase

Answer 10

gonadotrophin dependent phase
8 to 12 days
granulose cells secrete follicular fluid which coalesce in antrum
increases follicular size
synthetic activity maintained in the oocyte
morphological changes in the follicle

Question 11

preovulatory phase

Answer 11

LH and progesterone dependent
30-36 hours
meiotic maturation, expulsion of 1st polar body
withdrawl cytoplasmic processes
oocyte synthesis cortical granules
rapid expansion of volume of antral fluid
LH stimulated progesterone secretion by granulosa cells
hormone stimulated protease activity

Question 12

key follicular cells

Answer 12

granulosa
theca

Question 13

granulosa cells

Answer 13

from mesenchymal cells that condense around oogonium
nutritional support
FSH stimulates oestrogen produciton via aromatizaiton of androgens made by theca cells

Question 14

theca cells

Answer 14

arise from ovarian stroma that surround the primary follicles
LH stimulated production of androgens from circulating cholesterol
poor synthesis of oestrogens

Question 15

ovarian cycle

Answer 15

corups leuteum breaks down
decreasing oestrogne and progesterone, decreases negative feedback on hypothalamus and anterior pituitary
causes increase in LH and FSH from anterior pituitary (new cycle)
supports further development of 15-20 antral follicles
LH and FSH stimulate growth of follicles
LH stimulates androgen production in theca cells
FSH stimulates aromatase activity in granulosa cells for oestrogen production from androgen precurosr
oestrogens increase expression of FSH receptors on granulosa cells
stimulates granulosa cells proliferation
rise in oestrogen and inhibin
increases negative feedback so FSH falls and LH plateaus
most advanced follicle has increased FSH receptors
stimulated by lower FSH levels and continue devloping as it is the dominant follicle
less matrue follicles lose trophic support leading to atresia
LH stimulate androgens and FSH stimulate oestrogen production
providing trophic support to dominant follicle
androgens and oestrogens further stimulate cell proliferation and aromatase activity in granulosa cells causing oestrogen surge
oestrogen causes expression of LH recpetors on granulosa cells
at high plasma concentrations oestrogen stimulates LH and FSH from anterior pituitary causing positive feedback
LH surge
causes dominant follicle with LH receptors on theca and granulosa cells toenter pre-ovulatory phase
LH stimulates progesteron and reduction in oestrogen
at ovulation oocyte surrounded by cumulus oophorus cells is ejectied into the peritoneal cavity
granulosa and theca cells left in the follicle collapse around fibrin core forms corpus leuteum
in corpus leuteum under influence of LH granulosa cells stop dividing
hypertrophy and produce increasing levels of progesterone and oestrogen in lutein cells
hgih levels of porgesterone inhibits secretion of LH and FSH
overriding the positive feedback
preventing further ovulation
LH decreases, trophic support for corpus leuteum decreases
corpus leuteum regresses spontaneously and progesterone and oestrogen production decrease leading to menstruation

Question 16

primary hypogonadism

Answer 16

gondotrophins unresponsive gonads
called hypergonadotrophic hypogonadism

Question 17

example of primary hypogonadism and describe

Answer 17

Klinefelters snydrome. AID, turners
absent delayed puberty, low libido
reduced levels of sex steroids, reduced negative feedback
could be caused by leydig cell agensis gene mutations
treated wiht replacement therapy

Question 18

secondary hypogonadism

Answer 18

impaired secretion of LH and FSH by anterior pituitary or GnRH by hypothalamus
hypogonadotrophic hypogonadism

Question 19

examples of secondary hypogonadism

Answer 19

kalmanns syndrome
absent delayed puberty, low libido
reduced plasma concentration o LH and FSH, low sex steroids
caused by hypothalamus or pituitary falure
treated with replacement thrapy