HUMAN REPRODUCTION
,Puberty: the process of physical and physiological changes
● Leads to the development of secondary sex characteristics
● Leads to an immature individual becoming capable of reproduction
● Girls - 11 - 14
● Boys - 14 - 16
● Adolescence - period of physical, physiological and psychological change
How does it start?
● Pituitary gland is stimulated by the hypothalamus to release gonadotropins which initiate
puberty
- Males: interstitial-cell-stimulating hormone (ICSH) stimulates the testes to secrete
testosterone
- Females: follicle-stimulating hormone (FSH) stimulates the ovaries to produce
oestrogen
● Changes to the gonads - primary sexual characteristics (influence the process of
reproduction)
Puberty in girls:
● Breast development (10-12)
● Pubic hair (11-12)
● Increase in size of uterus, ovaries and primary follicles
● Widening of hips (wider birth canal)
● Start of menstrual cycle (12-18)
● First menstrual bleeding - Menarche (2 years after breast development)
● Ovulation
● Growth spurts (2-3 years long)
Puberty in boys:
● Enlargement of testes and penis
● Pubic hair (13-14)
● Increase in size of larynx and thickening of vocal chords
● Enlargement of skeletal muscles and broadening of shoulders
● Sperm production begins
● Growth spurt (2-3 years long)
, Male reproductive system:
,Puberty: the process of physical and physiological changes
● Leads to the development of secondary sex characteristics
● Leads to an immature individual becoming capable of reproduction
● Girls - 11 - 14
● Boys - 14 - 16
● Adolescence - period of physical, physiological and psychological change
How does it start?
● Pituitary gland is stimulated by the hypothalamus to release gonadotropins which initiate
puberty
- Males: interstitial-cell-stimulating hormone (ICSH) stimulates the testes to secrete
testosterone
- Females: follicle-stimulating hormone (FSH) stimulates the ovaries to produce
oestrogen
● Changes to the gonads - primary sexual characteristics (influence the process of
reproduction)
Puberty in girls:
● Breast development (10-12)
● Pubic hair (11-12)
● Increase in size of uterus, ovaries and primary follicles
● Widening of hips (wider birth canal)
● Start of menstrual cycle (12-18)
● First menstrual bleeding - Menarche (2 years after breast development)
● Ovulation
● Growth spurts (2-3 years long)
Puberty in boys:
● Enlargement of testes and penis
● Pubic hair (13-14)
● Increase in size of larynx and thickening of vocal chords
● Enlargement of skeletal muscles and broadening of shoulders
● Sperm production begins
● Growth spurt (2-3 years long)
, Male reproductive system:
