Placenta §
- some cells of embryo develop into the placenta, umbilical cord and amniotic sac
- PLACENTA COMES FROM BABY!!!!!!!!!!!
- Consists of:
- Uterine lining on which the embryo /foetus is attached
- Maternal blood spaces
- Finger-like structures called villi grow from the embryo into uterine lining to form placenta
- Secretes oestrogen, progesterone and hCG
- One umbilical vein transports transports glucose, amino acids, fatty acids, glycerol, mineral salts, oxygen and antibodies
- Two umbilical arteries transport metabolic waste such as urea and
- High pressure of mother
- Possibly different blood group
- May cause agglutination of blood
- Barrier to exclude disease-causing organisms, hormones and chemicals
- Protection is not complete
Amniotic Fluid §
- Yellowish watery stuff
- Supports and allows foetus to move freely
- Protects foetus from mechanical shock
- Lubricates vagina during childbirth
- Maintains a constant internal environment for the foetus
Amniotic Sac §
- Membrane that encloses foetus