Reproductive system

• When progesterone levels are high, oestrogen levels are low
• Progesterone maintains the lining of the uterus
• As oestrogen and progesterone levels increase, signals are sent to the hypothalamus and pituitary gland which inhibit the release of FSH and LH.
• Sexual reproduction involves male and female gametes fusing in the process of fertilisation
• The female reproductive system has two functions:

  •to produce egg cells – this occurs during the menstrual cycle

  •to protect and nourish an offspring until birth.
• The male reproductive system has one function:

  ·to produce and deposit sperm.
• •FSH Stimulates Oestrogen
• •Oestrogen stimulates LH and inhibits FSH
• •LH stimulates egg release
• •Progesterone inhibits both LH and FSH
• ••Ovaries produce Oestrogen and Progesterone
• •Pituitary gland produces LH and FSH
• The vagina:

  •It receives sperm during sexual intercourse.

  • It forms the birth canal along which the baby moves during childbirth.

  It allows loss of menstrual blood when the lining of the uterus breaks down during each cycle
• The cervix is the lower part of the womb that joins to the top of the vagina.
• Fallopian tubes connect the ovaries to the uterus. Egg cells are drawn down the fallopian tubes from the ovary and may be fertilised by a sperm cell. This may then pass down to the uterus.
• The cervix is a ring of muscle that acts as a barrier to the uterus
• •If an egg is fertilized and becomes an embryo, it will implant in the wall of the uterus and will develop into the foetus.
• The cervix remains closed during pregnancy and a plug of cervical mucus helps keep pathogens from infecting the fetus
• •At the end of pregnancy, the hypothalamus releases the hormone oxytocin.
• The penis has a dual function. The urethra connects to the bladder and provides an exit from the body for urine. The urethra is also connected, via the vas deferens, to the testes, which is where sperm is produced
• IVF STEPS

  Step 1: suppressing the natural menstrual cycle.

  Step 2: helping your ovaries produce more eggs.

  Step 3: checking progress.

  Step 4: collecting the eggs.

  Step 5: fertilising the eggs.

  Step 6: embryo transfer.
• factors affecting the number of embryos transferred:

  •age

  •IVF cycle

  •quality of embryos