Female endocrinology 1

Question 1

Proestrus follows what & proceeds what?

Answer 1

Follows dioestrus & precedes oestrus

Question 2

Major endocrine transition from what to what…?

Answer 2

From prog. dominance to oestrogen dominance

Question 3

What event sets off oestrus? What event ends proestrus?

Answer 3

Begins when prog. declines as a result of luteolysis

Ends at onset of oestrus

Question 4

In which phase does female allow mating ?

Answer 4

oestrus - length varies between spp.

Question 5

Dominant hormone in oestrous?

Answer 5

oestradiol

Question 6

What is standing oestrus?

Answer 6

female displays lordosis - back-arching behaviour in prep for mating & ‘stand strong’ when mounted

Question 7

4 major events in follicular phase…?

Answer 7

• ++ gonadotropins
• follicular growth & maturation
• sexual receptivity & behaviour (oestrogen)
• ovulation

Question 8

Re. oogenesis, where can maturation occur…?

Answer 8

follicular phase AND also mitotic & meiotic divisions occurring prenatally

Question 9

What happens to oocytes after prenatal mitotic & meiotic divisions?

Answer 9

Nuclear arrest until puberty where meiosis resumes

Question 10

What happens in the post-pubertal phase …?

Answer 10

post-pubertal phase - puberty (LH surge) -> meiosis continues
AND
ovulation & fertilisation occur

Question 11

What happens before ovulation…?

Answer 11

nucleus of oocyte -> periphery

first polar body formed just before ovulation

Question 12

How many chromosomes in a haploid cell

Answer 12

half

Question 13

Draw summary diagram for all hormones & phases with focus on ‘follicular phase’

Answer 13

slide 19…

Question 14

What happens in the follicular phase…?

Answer 14

decrease P4 from CL -> ++GnRH -> ++FSH & LH -> follicle (primordial follicles)

Question 15

Antral follicle made up of which 2 types of cells?

Answer 15

Theca interna cells 
  - LH receptors
  - produce T
Granulosa cells
  - FSH receptors
  - produce enzymes that convert T -> oestradiol

Question 16

Mare with Granulosa cells tumour

Answer 16

++oestrogen -> constant heat (nymphomaniacs) (remove ovary) = solution

Question 17

Mare with Theca-cell tumour

Answer 17

++ testosterone -> stallion-like behaviour (rounding up mare’s, mounting mares..)

Question 18

Proestral follicular dev.?

Answer 18

Follicles undergo growth & selection

Question 19

Estradiol threshold level…?

Answer 19

horses & cows -> inhibin (inhibits growth & maturation of all follicles surrounding it) -> FSH decreases but LH continues production -> preovulatory surge

Question 20

Effects of oestrogen…?

Answer 20

Changes in behaviour (lordosis, phonation, physical)
Changes in repro. tract (++blood flow, tissue oedema, ++mucous secretion, ++leukocytes, ++SM motility, ++uterine gland growth)
Changes in hypothamus

Question 21

Draw summary diagram of LH surge….

Answer 21

slide 18…

Question 22

Menopause is what?

Answer 22

When oocytes run out due to oocyte atresia

Question 23

During recruitment, what are the hormone levels doing…?

Answer 23

high FSH, low LH, no inhibin, low oestrogen

Question 24

During selection, what are the hormone levels doing…?

Answer 24

Low FSH, mod LH, low inhibin, mod oestrogen

Question 25

During dominance, what are the hormone levels doing…?

Answer 25

Low FSH, high LH, high inhibin, high oestrogen

Question 26

Major events of follicular phase…?

Answer 26

GnRH from hypothalamus
Follicular growth & maturation
Sexual receptivity & behaviour
Ovulation

Question 27

Follicular phase is made up of …?

Answer 27

Recruitment
Selection
Dominance

Question 28

T or F - oogenesis occurs only after birth

Answer 28

false - occurs before AND after birth

Question 29

Describe succinctly what ovulation is…

Answer 29

A cascade of biochemical & physiological changes which result in release of oocyte