1. 2. Hormonal control of reproduction
Hormones control the onset of puberty, sperm production and the menstrual cycle.
Which hormones cause the onset of puberty?
How do they exert their control?
Which hormone controls sperm production?
What other hormones are involved in sperm production?
Which hormones control the menstrual cycle?

2. At Puberty
Puberty is when sperm are produced and menstrual cycle commences.
Hypothalamus secretes a releaser hormone which affects pituitary gland
Pituitary gland produces
follicle stimulating hormone (FSH)
Interstitial cell-stimulating hormone (ICSH)(male)
Luteinising hormone (LH)(female)
ISCH and LH are same hormone but have different effects

3. Male hormonal affects
FSH stimulates sperm production in seminiferous tubules
ICSH stimulates interstitial cells to produce testosterone
Testosterone activates the prostate gland and seminal vesicles
System self regulates.
As testosterone levels rise they affect the pituitary gland
High levels will inhibit FSH and ISCH production
This is called negative feedback

4. Female hormone affects
FSH stimulates development of follicles and ovary tissues to secrete oestrogen
LH triggers ovulation, stimulates development of corpus luteum and progesterone production from corpus luteum
Oestrogen stimulates endometrium (uterus lining) to develop, makes cervical mucus easier to penetrate by sperm and stimulates pituitary gland to secrete LH
Progesterone stimulates further endometrial development (blood vessels) for implantation of blastocyst and inhibits secretion of FSH and LH by pituitary gland

5. Menstrual cycle Approximately 28 days but varies
2 phases follicular and luteal
You will summarise these 2 phases from the diagrams provided

6. OESTROGEN
PROGESTERONE

7. Oestrogen

8. Follicular phase
FSH stimulates follicle development and release of oestrogen from ovary tissues
Oestrogen causes release of LH and FSH
LH cause ovulation at about day 14
Egg can be fertilised in next 3-4 days

9. Luteal phase Following ovulation
LH stimulates follicle to become corpus luteum
Corpus luteum secretes progesterone (and oestrogen)
Progesterone stimulates endometrium development
Progesterone and oestrogen levels inhibit pituitary gland so FSH and LH levels fall
No new follicles develop at this stage
This is an example of negative feedback
No fertilisation – corpus luteum degenerates (about day 22)
No progesterone and oestrogen produced
About day 28 low hormone levels mean endometrium is not maintained and comes away (with a little blood)
Menstruation begins

10. What do you know now?
Hormones control the onset of puberty, sperm production and the menstrual cycle.
Which hormones cause the onset of puberty?
How do they exert their control?
Which hormone controls sperm production?
What other hormones are involved in sperm production?
Which hormones control the menstrual cycle?