Human reproduction by YuliaPresentation Transcript
UNIT 4HUMAN REPRODUCTION By Yulia
INDEX• HUMAN REPRODUCTION• REPRODUTION• The reproductive cells• The reproductive system• The male reproductive system• The female reproductive system• Fertilisation• Pregnancy• Labour
Reproduction• Primary sexual characteristics The reproductive systems• Secondary sexual characteristics: -girls develop breasts and their hips get wider -Boys get deeper voices
REPRODUCTIVE CELLSperm are the male reproductive cell. They are smalls. They have a head and a long tail called flagellum. They are produced in large numbers from the time of puberty. ova are the female reproductive cell. They do not move .From puberty, an ovum matures every month.
THE REPRODUCTIVE SYSTEMThe reproductive system is made up of these organs:• The ovaries produce ova• The utherus is where the baby develops• The fallopian tubes connect the ovaries to the uterus• The vagina connects the uterus to the outside of the body.• The vulva is the external part of the female reproductive system.
THE MALE REPRODUCTIVE SYSTEMThe male reproductive system is made up of these organs.• The testicles are outside the body. They produce sperm. They are covered by a bag of skin called the scrotum.• The vas deferens take sperm from the testicles to the urethra.• The urethra takes sperm outside the body.• The seminal vesicles and prostate produce seminal fluide and send it to the urethra.• The penis is outside the male reproductive system.
FERTILISATIONFertilisation occurs when an ovum and a sperm join inside the fallopian tubes
PREGNANCY• The placenta takes nutrients and oxygen from the mother’s blood to the embryo.• The umbilical cord connects the embryo to the placenta.• The amniotic sac protects the embryo. The baby develope step by step.• After 3 months: the embryo has all its organs. It becomes a foetus.• After 5 months: the baby’s body develops and it starts moving and the mother feels it.• After 9 months: the baby is ready to be born and it weighs around 3 kg
LABOURThe process of giving birth is called labour. Labour takes place in three phases:• Dilation rhythmic contractions make the opening of the vagina and vulva big enogh for the baby to come out.• Expulsion: the baby is born and the doctor cuts the umbilical cord.• Aftherbirth: the placenta comes out of the mother’s body.