Biol121 Week 12 Lecture A - Hormonal Regulation

Front 1

What are the major hormones of the reproductive system? (Male or female)

Back 1

- Testosterone (androgen)

- Oestrogen

- LH (pitu)

- FSH (pitu)

- GnRH (hypoth)

- Progesterone

Front 2

1. When is there an increase production of testosterone?

2. What are its (5) roles?

Back 2

1. Puberty

2. i) sperm production ii) libido iii) stimulate bone + muscle growth iv) male secondary characteristics e.g. facial hair v) maintain accessory glands.

Front 3

1. When is there an increase production of oestrogen?

2. What are its 5 roles?

Back 3

1. Puberty.

2. i) stimulate muscle and bone growth. ii) secondary characteristics (boobs) iii) maintaining accessory organs iv) libido v) endometrial growth and secretion

Front 4

Describe the chain of hormone events that produces testosterone + oestrogen (as well as inhibit)

Back 4

1. Hypothalamus releases GnRH

2. Anterior pituitary releases LH & FSH. Reaches testes & ovaries.

3. FSH = makes testes secrete inhibin. make ovaries secrete inhibin or oestrogen.

LH = makes testes secrete androgens. makes ovaries secrete progesterone or estrogen.

Hint 4

Front 5

What hormones are essential for spermatogenesis? Where are they released from?

Back 5

LH & FSH released from the anterior pituitary.

Front 6

What hormones influence nurse cells?

What does it do?

Back 6

FSH

Stimulates production of inhibin

Helps nurse cells support and regulate

Front 7

What hormones influence interstitial cells?

What does it do?

Back 7

LH

Produce testosterone

Front 8

What are the (2) ways negative feedback helps regulate hormonal control n men?

Back 8

1. Inhibin produced by FSH in testes will act on the hypothalamus to reduce GnRH secretion.

2. Testosterone reaches outside of the testes, brain will recognise high levels and reduce LH output

Front 9

What is happening to the follicle in the ovary in days 0-13 of the cycle?

What happens on day 14?

Back 9

Primordial follicles are maturing into primary, secondary, tertiary: AKA development.

14: Ovulation. Egg released to uterine tube with some cells. Most follicle tissue left behind.

Front 10

What happens to the cells left behind when the egg leaves during ovulation? Inc. function here.

What happens to this structure if you don't fall pregnant?

Back 10

These develop into the corpus luteum, which has a hormone-releasing function.

Regresses and dies, turns into corpus albicans

Hint 10

Front 11

What happens during days 0-7 of the cycle in the uterus.

Back 11

Mensies/the destruction of the functional.

Cells dying. Passing out of body.

Hint 11

Front 12

What happens days 7-14 of the cycle, in the uterus?

Back 12

Proliferation stage. Repair of endometrium.

Front 13

What happens during days 14-28 of the cycle, in the uterus?

Back 13

Secretory phase.

Glands secreting nutrients, mucous etc hoping to be pregnant

Front 14

What happens when the corpus luteum dies?

Back 14

The hormone it produces

Front 15

1. What happens in the first pre-ovulation / follicular phase? (Name days) (5 things)

Back 15

days 1-5

1. endo from last cycle shed

2. GnRH released from hypoth

3. FSH released from ant. pit

4. follicle in ovary contains egg

5. FSH stimulates follicle

Hint 15

Front 16

What happens in the second pre-ovulatory/follicular phase? (name days) (7 things)

Back 16

days 6-13

1. About 20 follicles start to grow

2. Follicles secrete inhibin + progesterone

3. One becomes dominant, rest regress

4. Rising estrogen & inhibin reduces FSH & LH (negative feedback) (makes only 1 follicle leave)

5. Rising estrogen stimulates endometrium (begins proliferation again)
6. when the ovum is ready 2 leave, high oestrogen has positive stim effect on LH secretion

7. LH levels surge

Front 17

what happens when LH surges?

Back 17

Ovulation. Day 14.

Front 18

What happens during the post-ovulation/luteal phase (5)? What days are this?

Back 18

15-28

1. Corpus luteum forms from remenants of follicle

2. Progesterone being produced from CL

3. Endo keeps developing.

4. @ 12 days (if no pregnancy), CL dies.

5. Therefore: progesterone stops being made, lining no longer supported, lining shed - back to the start!

Front 19

What are the two zones of the endometrium?

Describe them.

Back 19

1. Functional zone. Regularily grows and is shed.

2. Basilar zone. Permanent. Attaches endo to myo.

Front 20

1. What is degenerated during menses?

2. How is this achieved?

3. What is safe?

Back 20

1. The functional zone.

2. Artery constriction to zone because of lower progesterone.

3. The basilar zone.

Front 21

1. What is the dominant hormone during the proliferation phase?

2. What produces it?

3. What does it achieve (3)?

Back 21

1. Oestrogen.

2. Follicles.

3. Glycogen to endo, more vascularisation and growth

Front 22

1. What is the most important hormone during the secretory phase? Where is it made?

2. What happens now?

3. What dies during this phase?

Back 22

1. Progesterone from corpus lutem.

2. Increased vascularisation, secretions increase, glands enlarge.
3. Towards the end of this phase, the CL dies. No progesterone. Back to menses.

Front 23

What happens if there IS fertilisation and implantation during the secretory phase?

What initiates this?

Back 23

The corpus luteum DOESN'T die! Lining is NOT shed.

1. The implanted egg sends out hCG. Human chorionic gonadotropin.

Front 24

1. What is hCG?

2. What does it act on to do?

Back 24

1. Human chorionic gonadotropin.

2. Acts on corpus luteum to stay alive and keep producing progesterone.

Front 25

When does the CL finally die off? (If fertilization + implantation has happened)

What product decreases at this point as well?

Back 25

When the placenta has matured enough to be its own source of progesterone and estrogen.

Human chorionic gonadotropin.

Hint 25

Front 26

What does progesterone from the placenta do? (2)

Back 26

1. Maintains endometrium.

2. Suppresses uterine contractions.

Front 27

What does oestrogen do throughout pregnancy?

(2)

Back 27

Mamary gland development

Myometrium preparation (increased sensitivity)

Front 28

1. What causes menopause?

2. What is a hormonal result?

3. What are 3 results in oestrogen loss?

Back 28

1. Follicular shortage. 45-50.

2. Oestrogen production drops, no ovulation.

3. osteoporosis, neural effects (depression, hot flash), increased CVD risk

Front 29

What causes the surge of LH at day 14?

Back 29

The oestrogen levels being produced by the stimulated/growing follicles

It is a feedback mechanism of sorts

Front 30

What is the name of the hormone that the early fertilised + implanted embryo releases and sends as a message to the ovary?

Back 30

HcG

Human chorionic gonadotropin

Front 31

What is the role of HCG in the body?

Back 31

It encourages the corpus leteum to stay alive and continue producing progesterone