Transcript (en)

and local nerves cause two chambers called the corpus cavernosum, which contain a maze of blood vessels to relax, allowing blood to flow in and fill the open spaces. Blood runs the organ's length and creates pressure in the corpus cavernosum, making the penis expand and creating an erection. In females, the clitoris is a small sensitive organ located at the top of the genital cleft. There are thousands of nerve endings here. The clitoris consists of erectile tissue that fills with blood and expands when stimulated. This erectile tissue is similar to the tissue in the penis. The membrane surrounding the corpus cavernosum is called the tunica albiginia. It helps to trap the blood and sustain the erection. Erectile tissue surrounds the urethra two main arteries and several veins and nerves Ejaculation is a reflex action controlled by the central nervous system It is triggered when the sexual act reaches a critical level of excitement. Then the vas deferens contract to squeeze the sperm toward the base of the penis. The prostate gland and seminal vesicles release secretions to make semen. At this stage, the ejaculation is unstoppable. Muscles at the base of the penis contract every 0.8 seconds. and force the semen out of the penis in up to five spurts. .