Human Male Reproductive System

Overview

• The male reproductive system, though sharing the same primary function as the female system, consists of different parts.
• Main components include testes, epididymis, sperm duct, seminal vesicle, prostate gland, Cowper's gland (Bulbourethral gland), urethra, and penis.

Structure and Function

Testes

• Two ovoid testes located in scrotal sacs outside the body to maintain a lower temperature (~30°C) needed for sperm production.
• Spermatic cord contains blood vessels at the upper end of each testis.

Epididymis

• Narrow, coiled tube attached to each testis where sperm is stored in inactive form before entering the vas deferens (sperm duct).

Sperm Duct (Vas Deferens)

• Transports sperm from the epididymis into the abdominal cavity, loops over the ureter, and opens into the urethra.

Accessory Glands

• Seminal Vesicle: Opens into each sperm duct at the urinary bladder's base, secretes fluid rich in nutrients and enzymes.
• Prostate Gland: Located where sperm ducts join the urethra, contributes to seminal fluid.
• Cowper's Gland (Bulbourethral Gland): Secretes a slippery fluid that forms semen.

Semen

• A mixture of sperm and glandular secretions containing nutrients and enzymes to nourish and activate sperm.

Urethra and Penis

• Urethra: Tube carrying semen to the exterior during ejaculation.
• Penis: Contains erectile tissue that fills with blood upon stimulation, leading to erection for ejaculation.
• Internal urethral sphincter prevents urine and semen from passing simultaneously.

Sperm Anatomy

• Head: Contains a nucleus with chromosomes, minimal cytoplasm, and an acrosome with enzymes aiding in egg penetration.
• Middle Piece: Rich in mitochondria providing energy.
• Tail (Flagellum): Enables swimming towards the egg.
• Sperm size: 2.5 micrometers, 28 fit across the width of a human hair.

Puberty

• Marks the maturation of sex organs and gamete production.
• Typically begins around age 12 in boys, though earlier onset is seen possibly due to diet.
• Testosterone production increases, leading to secondary sex characteristics.

Hormonal Influence

• Testosterone: Male sex hormone produced by the testes, crucial for developing secondary sexual characteristics during puberty.