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I/GCSE Biology - Sexual Reproduction in Human

Sexual Reproduction in Human

July 11, 2021

Male ♂️

  • 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.

Female ♀️

  • 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. 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’. 👶

👇👇 The stages of labour: 👇👇

  1. 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.
  2. 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.
  3. 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)