NEET Biology Human Reproduction

SYNOPSIS

• Human Reproductive System
  
  

• The primary sex organs—the testes in males and the ovaries in females—produce gametes, i.e. sperms and ovum. This process is called gametogenesis.
  
  
• Spermatogenesis is the process where sperm mother cells in seminiferous tubules of the testes change into haploid spermatozoa.
  
  
• Oogenesis is the process of formation of haploid ova in the Graafian follicles of the ovary.
  
  
  
  
  
• Ovulation is the process where the mature ovum at the secondary oocyte stage is released from the ovary by the rupturing of its Graafian follicles.
  
  
• The first menstruation begins at puberty and is called menarche.
  
  
• A phase in a woman’s life where permanent cessation of menstruation occurs is called menopause.
  
  
• The menstrual cycle is the rhythmic series of changes in the sex organs which occur after every 28 days.

• Phases of the Menstrual Cycle
  
  

• The process of fusion of a sperm with an ovum is called fertilisation.
  
  
• Implantation is the fixing of the fertilised ovum in the tissues of the uterus.
  
  
• The placenta is an organic temporary connection between the mother and the foetus during pregnancy.
  
  
• Parturition is the process of expulsion of the foetus from the uterus.
  
  
• The signals for parturition originate from the fully developed foetus and the placenta which induce mild uterine contractions called foetal ejection reflex.
  
  
• Colostrum is the first milk which comes out from the mother’s mammary glands after the birth of the baby.