Vagina The vagina, from the Latin word meaning sheath, is the receptacle for the penis during sexual intercourse, the birth canal, and the outlet for the menstrual fl ow.

Surrounding the openings of the vagina and ure-

thra in the perineum of the female are the external genital structures. Bounding the openings on either side are the folds of skin called the labia majora and labia minora. Between these folds is the common entry way to both urethra and vagina, the vestibule. Deep to the labial skin are the erectile tissues of the female, the clitoris and bulb of the vestibule. The greater vestibular glands empty their lubricating secretions into the vestibule and opening of the vagina.

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Perineal dissection revealing details of external genitalia

Inferior view

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Like the female, there are both internal and external genital organs in the male.

The major difference between the sexes is the enlargement of the erectile tissue organs of the male and the descent of the gonads, the testes, from an internal position to a suspended position outside the body cavity. The male genital organs include the testes suspended in the scrotum. The testes consist of an extensive tubular system that gives rise to the sperm, which then pass through the tubular ducts of egress — the rete testis, epididymis, ductus deferens, ejaculatory duct, and urethra — to exit from the male body. Accessory glands of the male join the ducts of egress and add secretions to the sperm, and the erectile intromittant organ, the penis, introduces the sperm into the female system.

10Prostate gland

11Seminal vesicle

12Bladder

13Pubic symphysis

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Parasagittal section of male pelvis

Medial view

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