Primary and Secondary sexual characteristics

What are primary sexual characteristics? (2)

• Characteristics associated with persons sex that are directly involved in sexual reproduction

• Present at birth in immature form

What are secondary sexual characteristics? (2)

• Characteristics associated with persons sex that are not directly involved in sexual reproduction

• Usually changes that occur with pubertal development

What is puberty?

Stage of sexual maturation

What hormone is released at puberty and from where?

• Gonadotropin hormone-releasing hormone (GnRH)

• Released from hypothalamus

What does gonadotropin releasing hormone do?

Stimulates pituitary gland in the brain to release gonadotropins

What are the gonadotropins released by the pituitary in response to GNRH? (2)

• Follicle-stimulating hormone

• Luteinising hormone

What do Gonadotropins do? (3)

• Cause maturation of gonads in both genders

• Stimulate the secretion of testosterone in males

• Stimulate the secretion of progesterone and oestrogen in females 

What are female secondary sexual characteristics? (2)

• Breast development

• Broadening of hips (wider) and fat deposition

What does breast development include? (3)

• Deposition of fat

• Development of glands 

• Enlargement and darkening of nipples

What are male secondary sexual characteristics? (4)

• Larger body mass

• More muscle tissue

• Facial, chest and back hair

• Voice deepening

What does voice deepening include? (2)

• Increase in larynx size

• Lengthening of vocal cords 

What hormones controls pubic and axillary hair growth?

Hormones released by the adrenal glands

How does hair growth of pubic and axillary hair begin?

Sparse long, straight hairs

How does hair growth of pubic and axillary hair end?

Denser, dark curled hairs in a limited location 

What effect does testosterone have on the brain?

Acts on brain to promote sex drive

What effect does testosterone have on male genitalia?

Promotes maturation and maintenance of the testicles and penis

What effect does testosterone have on the body?

Promote development and maintenance of secondary sexual characteristics

What effect does testosterone have on the seminiferous tubules?

Promote spermatogenesis the development of spermatozoa in seminiferous tubules

What effect do oestrogen and progesterone have on the body?

Development and maintenance of female genitalia and secondary sexual characteristics

What effect do oestrogen and progesterone have on the endometrium?

Promotes repair and proliferation of endometrial lining