- Males have a penis, in which they use to pass urine out, and to deposit sperm in females.
- Sperm and male sex hormones are produced in the testis.
- During sexual intercourse, when the male experiences an orgasm, the sperm passes along the sperm duct and are mixed with a fluid made from the seminal vesicles (labeled ‘glands’).
- This mixture, called semen, is ejaculated into the vagina of the female, in which the sperm can then begin to swim towards the Fallopian tubes.
- One ovum is released from the ovaries into the Fallopian tube each month.
- If the ovum is present in the Fallopian tubes, it may be fertilized by the sperm.
- The zygote formed will begin to develop into an embryo and implant itself into the lining of the uterus.
- It will develop a placenta, which will allow the embryo to obtain oxygen and other nutrients from the mother’s blood, as well as get rid of waste products such as urea and carbon dioxide.
- The placenta also secrets progesterone to maintain pregnancy and prevent the embryo from aborting.
During pregnancy, a membrane called the amnion encloses the embryo, and secrets amniotic fluid, which protects the developing embryo against jolts. In I/GCSE Biology, when it becomes recognizably human, the embryo is called a fetus. After nine months, the fetus sends a hormonal signal to the mother to initiate birth. This is called ‘going into labour’. 👶
- Dilation of the cervix – cervix gets wider to allow the baby to pass through. The muscles of the uterus contracts and ruptures the amnion, allowing the amniotic fluid to escape.
- Delivery of the baby – strong contractions of the muscles of the uterus push the baby head first through the cervix and vagina, and out of the mother.
- Delivery of the afterbirth – the placenta, along with the membranes that surrounded the baby, gets pushed out.
That's the end of the topic!
Drafted by Joey (Biology)