Human Reproduction

General Information

• Human reproduction is divided into male and female.
• The male reproductive system is located in the pelvic region.

Male Reproductive System

Main Organs

• Primary Sex Organs:
  • Testis
• Secondary Sex Organs:
  • Accessory glands
  • Vas deferens
  • Seminal vesicle
  • Prostate gland
  • Cowper's gland (Bulbo-urethral gland)

Testis

• Number of testes: Two (pair)
• Shape: Oval
• Length: 4-5 centimeters
• Located in the scrotum, which is outside the abdominal cavity.
• Sperm production occurs in the seminiferous tubules.

Sperm Production

• Occurs in the process of spermatogenesis:
  1. Spermatocytogenesis: Process of forming spermatids from spermatogonia.
  2. Spermiogenesis: Process of forming sperm from spermatids.
• Structure of sperm: Head, neck, middle piece, tail.
• The head contains an acrosome that dissolves the membrane around the egg.

Female Reproductive System

Primary Sex Organs

• Ovary:
  • Number: One pair
  • Size: 2-4 centimeters
  • Located inside the abdominal cavity.

Secondary Sex Organs

• Fallopian tube, uterus, cervix, vagina, vulva (external genitalia)
• Vulva includes:
  • Mons pubis
  • Labia majora
  • Labia minora
  • Clitoris
  • Hymen

Oocyte Production (Oogenesis)

• Process:
  1. Multiplication Phase: Production of oogonia.
  2. Growth Phase: Production of primary oocytes.
  3. Maturation Phase: Production of secondary oocytes.

Menstrual Cycle

• Three phases:
  1. Menstrual Phase:
     • Endometrium breaks down over a period of 3-5 days.
  2. Follicular Phase:
     • Levels of estrogen and progesterone increase.
  3. Luteal Phase:
     • Formation of corpus luteum, secretion of estrogen and progesterone.

Reproduction

• Fertilization:
  • Occurs in the fallopian tube.
  • Formation of diploid zygote.
  • Implantation: By blastocyst in the uterus.

Placenta

• Process of nutrition and gas exchange between the embryo and the mother.
• Placenta is the structural and functional unit of the embryo and mother.

Birth Process (Parturition)

• Two signals: Placenta and fully developed fetus.
• Contractions in the uterus and the birth of the baby.

Lactation

• Milk production in the mother's mammary glands.
• The first milk is called colostrum.

Conclusion

• This chapter covers all the important aspects of human reproduction.
• Study keeping in mind the main points of NCERT.
• Learn as much as you understand.