biology

• female reproductive system

  
• Gametes

  Male and female sex cells
• Fertilisation

  When a sperm and egg join to form an embryo
• Gametes

  • Specialised cells with adaptations to increase chances of fertilisation and successful development of a baby
• Conception

  1. Sperm fertilises an egg

  2. Ovaries produce eggs and hormones

  3. Egg travels to uterus

  4. Cervix allows sperm in and menstrual blood out

  5. Vagina connects cervix to outside
• Male reproductive system

  • Produces sperm cells and male sex hormones
  • Sperm pass through sperm ducts and mix with fluids to form semen
  • Semen exits through penis
• Female reproductive system

  • Ovaries contain eggs and produce female sex hormones
  • Oviducts move egg to uterus
  • Uterus is where baby develops
  • Cervix keeps baby in place during pregnancy
  • Vagina is birth canal
• Gestation and birth


  1. Fertilised egg divides to form embryo

  2. Embryo attaches to uterus and develops into fetus

  3. Fetus relies on mother for protection, oxygen, nutrients, waste removal

  4. Placenta provides oxygen and nutrients, removes waste

  5. Cervix relaxes and uterus contracts to push baby out through vagina
• male reproductive system

  
• egg - 23 chromosomes

  sperm- 23 chromosomes

  zygote- 46 chromosomes in 2 pairs

  embryo- 46 chromosomes in 2 pairs
• The placenta is an organ responsible for providing oxygen and nutrients, and removing waste substances. It grows into the wall of the uterus and is joined to the fetus by the umbilical cord.

  The mother's blood does not mix with the blood of the fetus, but the placenta lets substances pass between the two blood supplies:

  • oxygen and nutrients diffuse across the placenta from the mother to the fetus
  • carbon dioxide and other waste substances diffuse across the placenta from the fetus to the mother
• Days 1-5

  Bleeding starts as the lining of the UTERUS breaks down and passes out of the VAGINA.

  Days 6-13

  EGG cells start to mature and the lining of the UTERUS starts to build up again.

  Day 14

  An EGG is release from the ovary.

  This is called OVULATION

  Day 15-17

  The EGG travels down the fallopian tubes towards the UTERUS.

  Days 15-28

  The UTERUS wall will stay thick for a while.

  It is waiting for a EGG to be fertilised.

  Day 28

  If the EGG is not fertilised, the UTERUS lining will shed again.

  If the EGG is fertilised the cycle stops, and the uterus lining remains thick.
• Sexual intercourse involves inserting the penis into the vagina. During sexual excitement, the male testicles release SPERM which travel along the vas deferens and are stored in the seminal vesicle until ejaculation. At ejaculation, the sperm are mixed with SEMINAL FLUID and passed out of the body through the PENIS.
• Females have ovaries that produce EGGS (ova). The eggs are released once every month during ovulation. They move towards the fallopian tubes where they may be fertilized by sperm. If no fertilization occurs, the egg disintegrates and is absorbed by the body.
• reproduction

  
• Reproduction


  Learning Objectives
• Label the male and female reproductive system and describe the functions of the main organs

  1. Label

  2. Describe functions
• Describe the main events in the menstrual cycle

  Describe events
• Describe the role of estrogen and progesterone in the menstrual cycle

  Describe role
• Describe in outline the process of sexual intercourse and how fertilisation occurs in humans


  1. Describe process

  2. Describe fertilisation
• Sperm


  Sperm is made here
• Testis


  Carries semen and urine out of the body
• Urethra


  Holds the testis outside the body to keep them at correct temperature
• Scrotum


  Male genital organ
• Penis


  Carries sperm from the testis to urethra
• Sperm duct


  The male gamete (sex cell) that carries ½ of the male's DNA
• Reproduction


  The middle piece of the sperm cell contains mitochondria
• Acrosome


  Contains digestive enzymes
• When a man and woman are sexually excited


  1. Woman's vagina becomes moist

  2. Man's penis becomes hard and large

  3. Penis is moved in and out of vagina

  4. Sexual intercourse is taking place

  5. Semen containing sperm is ejected into vagina

  6. Sperm swim through uterus and into oviducts

  7. Sperm enters egg

  8. Fertilisation takes place

  9. Fertilised egg develops into embryo, then foetus, then baby

  10. Woman becomes pregnant

  11. If sperm don't reach egg, fertilisation and pregnancy won't occur

  12. Family planning aids try to stop fertilisation