Sex steroid physiology

Question 1

What is a polar body?

Answer 1

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

Question 2

What does the presence of two polar bodies mean?

Answer 2

Sperm entry and completed 2nd meiotic division

Question 3

What are the two stages of the ovarian cycle?

Answer 3

Follicular stage

Luteal stage

Question 4

What is a primary follicle?

Answer 4

Primary oocyte surrounded by a single layer of granulosa cells

Question 5

What process ends the follicular phase?

Answer 5

Ovulation

Question 6

What is the corpus luteum?

Answer 6

Follicular cells which are lutenised

Question 7

What hormone does the corpus luteum secrete?

Answer 7

Progesterone

Question 8

What does the progesterone do?

Answer 8

Prepares the uterus lining for implantation

Question 9

How long does the corpus luteum grow for?

Answer 9

8-9

Question 10

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

Answer 10

It degenerates

Question 11

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

Answer 11

Gonadotropin releasing hormone GnRH

Question 12

Which two hormones does the anterior pituitary secrete?

Answer 12

FSH

LH

Question 13

What does FSH do?

Answer 13

Acts on the ovary and stimulates the development of follicles

Question 14

What does LH do?

Answer 14

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

Question 15

What are theca cells?

Answer 15

Cells which make up the follicle

Question 16

What do theca cells do?

Answer 16

Produce androgen which are converted to oestrogens

Question 17

What does oestradiol do?

Answer 17

Thickens the endometrium and thins cervical mucus

Question 18

What suppresses FSH production?

Answer 18

Oestrogen

Question 19

What do the granulosa have?

Answer 19

LH receptors

Question 20

What happens to hormone levels during ovulation?

Answer 20

LH and FSH levels fall

Question 21

How is ovulation detected?

Answer 21

? High levels of LH

Question 22

What happens if no hCG is produced?

Answer 22

Corpus luteum degenerates and forms the corpus albicans

Question 23

What is the corpus albicans?

Answer 23

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

Question 24

Which enzyme converts androgens from theca cells to oestrogens?

Answer 24

Aromatase enzyme

Question 25

Where does the converting enzyme come from?

Answer 25

Granulosa cells

Question 26

What stimulates the theca cells to produce androgens?

Answer 26

LH

Question 27

What does FSH do?

Answer 27

Stimulates granulosa cells to convert androgens

Question 28

In which phase of the cycle is LH high?

Answer 28

Follicular phase

Question 29

What will inhibit FSH?

Answer 29

High oestrogen levels due to negative feedback

Question 30

What happens when oestrogen peaks?

Answer 30

LH rises

Question 31

What happens when LH rises?

Answer 31

Ovulation occurs

Question 32

What happens during ovulation?

Answer 32

Oocyte is released from the ovary into the fallopian tube

Question 33

What do the granulosa and theca cells develop into?

Answer 33

Corpus luteum

Question 34

If progesterone levels are too high what will happen?

Answer 34

FSH/ LH is inhibited