Download 1.5 Individual human development during youth: Physical

1.5 Individual human development
during youth: Physical
Physical Development
Primary and Secondary Sex
Characteristics
• Primary sex characteristics are those change
that are directly involved in REPRODUCTION –
these will involve enlargement of sex organs
eg: penis and vagina
• Secondary sex characteristics are not directly
required for reproduction. So they will involve
all the other changes that occur during
puberty eg: widening of shoulders, pubic hair,
oily skin, breast development.
Primary & Secondary sex
characteristics
MALES
Primary sex characteristics
Growth of scrotum &
testes
Secretion of hormones
related to sperm
production
Growth of penis
2ndry sex characteristics
Body & facial hair
More muscle mass
Greater height than
females
Broadening shoulders
SIMILARITIES
• Pubic hair
• Oily skin
• Voice
deepens
• Acne
• Increase in
height
• Increase in
body odour
FEMALES
Primary sex characteristics
Increase in size of vagina &
uterus
Ovaries produce hormones
to start the menstrual cycle
Secondary sex
characteristics
Hips widen
Development of breasts
Distribution of fat to hips
Body gets curvier
Hormone
Gland that secretes Role it plays in physical
it / them
development during puberty
Follicle Stimulating
Hormone (FSH)
&
Lutenising
Hormone (LH)
Pituitary gland (in
brain)
Act on the testes and ovaries
to release testosterone or
oestrogen
Testosterone
Testes (testicles)
Responsible for the
development of male sex
characteristics, muscle
growth, hair growth and
voice changes
Oestrogen
Ovaries
Responsible for the
development of female sex
characteristics, breast
development and the
regulation of the menstrual
cycle.
Growth Hormone
(GH)
Pituitary Gland
Increases the rate of growth
Thyroxine
Thyroid Gland
Regulates metabolism, which
is required to produce the
extra energy needed for the
changes that occur to the
body during puberty.
Hormone actions on the female body
• For females:
GnRH is released from
the brain
• For males:
Oestrogen is released from
the ovaries which results in
female characteristics
developing
FSH and LH are released
from the pituitary gland
(brain)
LH and FSH act on the
ovaries
Hormone actions on the male body
GnRH is released from the brain
FSH and LH are released
from the pituitary gland
(brain)
Testosterone is released from the
testes which results in the male
characteristics developing
LH and FSH act on the testes