1. Higher Human Biology Unit 2
Chapter 8a
Reproductive Organs and Hormonal Control Male

2. Learning Intentions Learning Intentions:
What is the structure and function of the male reproductive organs?
What are the functions of the hormones involved?
Success criteria
Role of seminiferous tubules
Role of interstitial cells
Role of prostate gland and seminal vesicles
Function of hormones FSH, ICSH and testosterone
Role of negative feedback

3. Structure of male reproductive system
Bladder
Sperm duct
Seminal vesicle
Urethra
Prostate gland
Penis
Testis

4. Testis - close up
Interstitial cells
Interstitial cells

5. Male reproductive system cont’d
What is the purpose of the seminal vesicles?
Accessory gland
Produce fluid rich in fructose and the hormone prostaglandin
- fructose for energy source for high quantity of mitochondria in tails of sperm
- prostaglandin stimulates contraction of female reproductive tract to help sperm move up to oviduct more quickly
What is the purpose of the prostate gland?
Produces lubricating liquid
Liquid contains enzymes
Enzymes maintain viscosity of semen for maximum sperm motility

6. What are the functions of the hormones involved?
The pituitary gland is an endocrine gland
Secretes many hormones directly into the bloodstream
Two of these are male gonadotrophic hormones:
- follicle stimulating hormone (FSH)
- interstitial cell stimulating hormone (ICSH)
Both of these begin to be produced, by the anterior pituitary, at onset of puberty
Target tissue male gonads

7. What is the function of FSH? What is the function of ICSH?
Follicle stimulating hormone
Promotes sperm production from germline cells in seminiferous tubules
What is the function of ICSH?
Interstitial cell stimulating hormone (ICSH)
Interstitial cells found between seminiferous tubules
Stimulates interstitial cells to produce testosterone

8. What is the function of testosterone?
Stimulates sperm production in seminiferous tubules
Activates prostate gland and seminal vesicles to produce their secretions
Testosterone levels are controlled by negative feedback
- high levels detected by anterior pituitary
- production of FSH and ICSH inhibited
- testosterone levels decrease
- anterior pituitary releases FSH and ICSH again

9. Seminal vesicles produce fluid rich in fructose and hormone prostaglandin
Prostate gland produces lubricating fluid containing enzymes which maintain viscosity of semen for sperm motility
Testosterone acts here to stimulate seminal vesicles and prostate gland to produce their secretions
FSH acts here to promote the Seminiferous tubules within the testes to produce sperm
ICSH acts here to stimulate the Interstitial cells are in between the seminiferous tubules to produce testosterone
Testosterone stimulates sperm production in seminiferous tubules