Human Reproduction

Reproductive System

Male Reproductive System

• It is located in the pelvic region.

• It consists of:

  • A pair of testes

  • Accessory glands and ducts

  • External genitalia

Testes

• ​Situated within the scrotum, which protects the testes and also helps in maintaining the temperature.

• Each testis is 4 to 5 cm in length, and 2 to 3 cm in width, and has about 250 compartments called testicular lobules.

• Testicular lobules have seminiferous tubules which are the sites of sperm formation.

• Seminiferous tubules are lined by two types of cells:

  • Male germ cells − They undergo meiosis to form sperms.

  • Sertoli cells − They provide nourishment to the germ cells.

• Region outside the seminiferous tubules is called the interstitial space, which contains Leydig cells (interstitial cells). The Leydig cells produce androgens.

Accessory Ducts and Glands

• Accessory ducts include:

  • Rete testis

  • Vasa efferentia

  • Epididymis

  • Vas deferens

• The seminiferous tubules open into the vasa efferentia through the rete testis.

• The vasa efferentia open into the epididymis, which leads to the vas deferens. The vas deferens opens into the urethra along with a duct from the seminal vesicle called the ejaculatory duct.

• The ejaculatory duct stores the sperms and transports them to the outside

• The urethra starts from the urinary bladder, extends through the penis and opens via the urethral meatus.

• Accessory glands include:

  • A pair of seminal vesicles

  • Prostate gland

  • A pair of bulbourethral glands

• The secretions of these glands make up the seminal plasma, and provide nutrition and a medium of motility to the sperms.

Female Reproductive System

• It is located in the pelvic region:

• It includes:

  • A pair of ovaries
  • A pair of oviducts
  • Uterus
  • Cervix
  • Vagina
  • External genitalia
  • Mammary glands (not part of the reproductive system, but aids in child care)

Ovaries

• They are the primary female sex organs. They produce the ovum and other ovarian hormones.
• They are located in the lower abdomen, and are 2 to 4 cm in length.
• They are connected by ligaments to the pelvic walls and to the uterus.
• Each ovary is covered by epithelium, and contains the ovarian stroma.

• The ovarian stroma is made up of:

  • Peripheral cortex
  • Inner medulla

Oviducts

• They are also called fallopian tubes.
• They are 10 to 12 cm long, and extend from the ovary to the uterus.
• The part of each oviduct lying towards the ovary is funnel shaped, and is called infundibulum. It has finger-like projections called fimbriae.
• The infundibulum leads to the ampulla, and then to the isthmus, which has a narrow lumen opening into the uterus.

Uterus

• It is also called womb, and is pear shaped.
• It is connected to the pelvic walls by ligaments.

• The uterine wall consists of:

  • External perimetrium
  • Middle myometrium
  • Internal endometrium, which lines the uterine cavity
• The endometrium undergoes changes during the menstrual cycle.

Cervix and Vagina

• The cervix connects the uterus to the vagina.
• The cervix and the…