Human Reproduction

• Function and location of testes

  Responsible for producing sperm, which is the male gamete, as well as the hormone testosterone + Within the scrotum on either side of penis
• Scrotum


  Keeps the testes at their optimum temperature for meiosis: 35oC (this is slightly colder than the optimum temperature for our bodies which is 37oC) + Sac of skin located under penis
• Epididymis


  Sperm is stored and matures here
• Sperm duct


  Carry sperm from the epididymis to the urethra in the penis.
• Urethra 


  To carry sperm and urine through the penis.
• Cowper's Gland

  Prostate Gland

  Seminal Vesicles


  These three glands are responsible for adding seminal fluid into the sperm duct.
• Penis


  The penis is responsible for placing sperm inside the female body.
• Functions of seminal fluid

  It provides a medium for the sperm to swim.

  It nourishes the sperm as it contains the sugar fructose.

  It mixes with sperm to produce semen.
• Ovaries


  The ovaries produce the hormones oestrogen and progesterone. The Graafian follicle is a small sac within each ovary and it produces the female gamete: the egg.
• Gamete


  A gamete is a haploid sex cell, i.e. the egg or the sperm, and it is produced by meiosis.
• Fallopian tubes/Oviducts


  Cilia in the fallopian tubes help carry the egg from the ovaries to the uterus. Peristalsis (the contraction and relaxation of the muscles in the fallopian tube) also helps transport the egg.

  Fertilisation also occurs in the fallopian tube.
• Uterus


  Implantation

  Carrying the foetus

  Forming of the placenta in the case of pregnancy
• Endometrium


  The endometrium thickens with blood vessels and nourishment for the embryo in case of pregnancy.

  If pregnancy does not occur, the endometrial lining breaks down and is shed from the body during menstruation.
• Cervix


  It widens during labour to help the baby exit the body.

  It facilitates the entry of sperm into the female body and towards the fallopian tubes.
• Vagina


  Allows the entry of sperm during sexual intercourse.

  Birth canal (baby exits the uterus through the vagina).
• Hormones


  Hormones are chemical messages produced by endocrine glands and carried to another part of the body through the bloodstream where it has a specific effect.
• Male hormones and their function

  FSH - pituitary gland, stimulates meiosis

  LH - pituitary gland, stimulates the production of testosterone

  Testosterone - produced in testes, develop the male secondary sex characteristic
• Structure of sperm


  The head, the middle, and the tail.
• Oestrogen


  Develops and maintains the female secondary sexual characteristics.

  Produced in the Graafian follicle in the ovaries.
• Progesterone


  Develops and maintains the female secondary sexual characteristics.

  Produced in the corpus luteum in the ovaries.
• Structure of the egg

  The female gamete has the same structure as most cells.

  It is surrounded by a cell membrane.

  It is filled with the liquid cytoplasm.

  It contains a nucleus with 23 chromosomes, as it is a haploid cell.