The Male Reproductive System - Practice Questions & MCQ

• The male reproductive system is located in the pelvic region.
• It includes a pair of testes along with accessory ducts, glands and the external genitalia.

Scrotum:

• It is a pouch-like structure made up of deeply pigmented skin. 
• It is located as two separate sacs.
• It acts as a temperature-control system for the testes because they need to be slightly cooler than body temperature for normal sperm development. 
• The cremaster muscles in the wall of the scrotum relax to allow the testes to hang farther from the body to cool or contract to pull the testes closer to the body for warmth or protection.
• The scrotum remains connected with the wall of the abdominal cavity through the inguinal canals. 
• The spermatic cord or gubernaculum made up of spermatic artery, vein and nerves pass into the testes through the inguinal canal.
• Any damage to inguinal tissue may cause bulging out of intestine into the scrotum. Such a condition is called an inguinal hernia.

Testes:

• There is a pair of testis whose size is 4.5 cm x 2.5 cm x 3 cm. 
• It is oval in shape and pink in colour.
• Testes are held in the scrotal sac by thick fibrous tissue called spermatic cord or gubernaculum.
• The peritoneum, called mesorchium supports the testes.
• Each testis is surrounded by three layers:
  • Tunica vaginalis: is the visceral layer of peritoneum.
  • Tunica albuginea: is a dense fibrous cover under the tunica vaginalis.
  • Tunica vasculosa: is a loose connective tissue and blood vessels.
• Tunica albuginea internally divides each testis into 200-300 lobules called testicular lobules.
• Each of these lobes consists of 1—3 convoluted seminiferous tubules. 
• Seminiferous tubules is a tubular structure and its walls are made up of germinal cuboidal epithelium.
• There are two kinds of cells found in seminiferous tubules:
  • spermatogenic cells (germ cells) 
  • Sertoli or supporting cells (nurse cells): These secrete Androgen Binding Protein (ABP) that concentrates testosterone in the seminiferous tubules. They also secrete inhibin.
• Between the seminiferous tubules, Leydig cells or Interstitial cells are found. 
• These are polygonal in shape and secrete a male steroid hormone called testosterone.
• Testosterone controls the development of secondary sexual characters in males.