Biology LC - Human reproduction 3

Stage 1 of Copulation (Sexual arousal)

• in males: blood flows into the penis faster than it can flow out causing it to become erect

• In females: the vagina becomes lubricated, elongated and wider

Stage 2 of copulation (Sexual Intercourse)

the insertion of the erect penis into the vagina

Stage 3 of copulation (Orgasm)

• occurs when sexual arousal reaches a maximum

• orgasm in both males and females is caused by the contraction of pelvic muscles that surround sex organs

Insemination

the release of semen into the vagina.

• the egg releases a chemical to attract the sperm

• this is called chemotaxis

Fertilisation

the fusion of the egg cell and the sperm cell to a diploid zygote (occurs in fallopian tube)

Implantation

the embedding of the fertilised egg in the lining of the uterus

• amnion develops around the embryo

• amniotic fluid is secreted which acts as a shock absorber

• then placenta forms

Placenta

• supplies nutrients from mother to embryo

• gas exchange

• production of hormones

• the removal of wastes

• prevents the entry of certain pathogens

Lactation

the production of milk by the mammary glands of the female

Breastfeeding

the feeding of a baby directly from the breast

IVF

the process of fertilising an egg cell with a sperm cell outside of the body