Sex steroid physiology Flashcards Preview

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Flashcards in Sex steroid physiology Deck (34)
1

What is a polar body?

Produced in oogenesis. Doesn't have the ability to be fertilised

2

What does the presence of two polar bodies mean?

Sperm entry and completed 2nd meiotic division

3

What are the two stages of the ovarian cycle?

Follicular stage
Luteal stage

4

What is a primary follicle?

Primary oocyte surrounded by a single layer of granulosa cells

5

What process ends the follicular phase?

Ovulation

6

What is the corpus luteum?

Follicular cells which are lutenised

7

What hormone does the corpus luteum secrete?

Progesterone

8

What does the progesterone do?

Prepares the uterus lining for implantation

9

How long does the corpus luteum grow for?

8-9

10

What happens to the corpus luteum if pregnancy does not occur?

It degenerates

11

What hormone does the hypothalamus secrete which acts on the anterior pituitary?

Gonadotropin releasing hormone GnRH

12

Which two hormones does the anterior pituitary secrete?

FSH
LH

13

What does FSH do?

Acts on the ovary and stimulates the development of follicles

14

What does LH do?

Acts on ovary and stimulates follicle maturation, ovulation and development of the corpus luteum

15

What are theca cells?

Cells which make up the follicle

16

What do theca cells do?

Produce androgen which are converted to oestrogens

17

What does oestradiol do?

Thickens the endometrium and thins cervical mucus

18

What suppresses FSH production?

Oestrogen

19

What do the granulosa have?

LH receptors

20

What happens to hormone levels during ovulation?

LH and FSH levels fall

21

How is ovulation detected?

? High levels of LH

22

What happens if no hCG is produced?

Corpus luteum degenerates and forms the corpus albicans

23

What is the corpus albicans?

Connective tissue of type I collagen which forms form the corpus luteum

24

Which enzyme converts androgens from theca cells to oestrogens?

Aromatase enzyme

25

Where does the converting enzyme come from?

Granulosa cells

26

What stimulates the theca cells to produce androgens?

LH

27

What does FSH do?

Stimulates granulosa cells to convert androgens

28

In which phase of the cycle is LH high?

Follicular phase

29

What will inhibit FSH?

High oestrogen levels due to negative feedback

30

What happens when oestrogen peaks?

LH rises

31

What happens when LH rises?

Ovulation occurs

32

What happens during ovulation?

Oocyte is released from the ovary into the fallopian tube

33

What do the granulosa and theca cells develop into?

Corpus luteum

34

If progesterone levels are too high what will happen?

FSH/ LH is inhibited