Reproduction and the Sex Steroid Axis Flashcards Preview

The Endocrine System > Reproduction and the Sex Steroid Axis > Flashcards

Flashcards in Reproduction and the Sex Steroid Axis Deck (35)
Loading flashcards...
1

What is the range in days for a normal menstual cycle?

21-35

2

Usually ovulation occurs at around day __

Usually ovulation occurs at around day 14

3

Which hormones stimulate follicle development?

FSH and LH

4

In the menstrual cycle, why does oestrogen levels increase throughout the follicular phase?

FSH and LH stimulate granulosa cells surrounding the egg

The granulosa cells increase in size and secrete insulin

5

The follicular phase begins when levels of which hormone are low?

Oestrogen

6

What is the impact of rising oestrogen levels in the menstrual cycle?

Uterine lining thickens

7

After ovulation, what does the empty follicle become and which hormone does it secrete?

Corpus luteum

Progesterone

8

What causes ovulation?

LH surge

9

What causes rupture of the follicle wall allowing for the release of the egg?

Proteolytic enzymes and prostaglandins

10

Which two hormones remain fairly low in concentration throughout the follicular phase?

  1. Oestrogen
  2. Progesterone

11

What triggers menstruation?

Lack of hCG

Corpus luteum breakdown and subsequent progesterone decrease

 

12

Describe the HPO axis

  1. Hypothalamus secretes GnRH
  2. Pituitary secretes FSH/LH
  3. Ovaries produce oestrodiol, activins and inhibins

13

Which part of the hypothalamus produces GnRH?

Arcuate nucleus

14

Which cells does LH act on in order to produce oestrogen?

Theca cells

15

Which cells does FSH act on in order to produce oestrogen?

Granulosa cells

16

Which variant of GnRH is responsible for reproductive function?

GnRH1

17

What are the key functions of FSH?

  1. Recruits dominant follicle
  2. Granulosa cell growth
  3. Activates aromatase activity

18

What is inhibin and what does it do?

Local peptide in follicular fluid

Negative feedback on pituitary FSH secretion

Enhances local LH-induced androstenedione production

19

What is activin and what does it do?

Local peptide found in follicular fluid

Stimulates FSH induced oestrogen production

20

Into which two components are the testes organised cellularly?

  1. Tubular components
  2. Interstitial components

21

What are the two tubular components of the testes?

  1. Sertoli cells
  2. Germ cells

22

What are the two interstitial components of the testes?

  1. Leydig cells
  2. Capillaries

23

Which cells support germ cells within the testes in their development?

Sertoli cells

24

Which hormone acts on

a) Sertoli cells

b) Germ cells

a) FSH

b) LH

25

How long does spermatogenesis take?

Roughly 90 days

26

Which two hormones stimulate spermatogenesis?

FSH and testosterone

(LH stimulates testosterone production)

27

For which reasons is an oocyte much larger than a sperm cells?

  1. Yolk proteins
  2. Ribosomes
  3. t-RNA
  4. m-RNA
  5. Protective chemicals

28

Where does fertilisation occur?

Ampullary region of the Fallopian tubes

29

What is capacitation?

The functional maturation of a spermatozoon (mature sperm)

30

Where does capacitation occur?

Female reproductive tract