The Male Reproductive System - External Genitalia

External genitalia:

• The penis is the male external genitalia functioning as a copulatory organ found in erectile men.
• It is a cylindrical, erectile, pendulous organ suspended from the pubic region in front of the scrotum.
• It remains small and flaccid but on sexual arousal, it becomes long, hard, and erect, ready for copulation (coitus or intercourse).
• On average, about 15 cm long.
• It is made of a special tissue that helps in the erection of penis to facilitate insemination.
• The enlarged end of the penis called glans penis.
• Glans penis is covered by a loose fold of skin called foreskin or prepuce.
• The penis has three columns of erectile tissue beneath the skin: two dorsal cylinders of the corpora cavernosa of the penis and one ventral cylinder, the corpus spongiosum.
• The tunica albuginea, or dense connective tissue, covers the corpora cavernosa of the penis and urethra. The fibres of tunica albuginea surround both the cords jointly and also form a separate sheath around each cord.
• Some fibers form a partition called a septum penis between these cords.
• The third, smaller cord forms that part of the penis that remains inferior-anterior in an erect penis.
• The urethra runs through this cord.
• Urine and sperm are both excreted from the body via the penis.
• The urethra is housed in the corpus spongiosum.
• Corona is the margins of the penile glands. The surface of glans is formed of thin, smooth and shiny, hairless skin. The baseline of the glans is referred to as the neck of the penis. At the tip of the glans penis is the slit-like external urethral orifice or meatus by which the urethra opens out and discharges urine or semen.  
• Tyson’s gland or preputial glands, present in the skin of the penis neck, secrete a white sebaceous substance called smegma.
• Microbial infection in smegma can cause irritation due to inflammation. 
• Sperm storage: Sperms are stored for the most part in the vasa efferentia, epididymis, and proximal parts of vasa deferentia.