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Sexual Anatomy. Female-External Female-Internal Male-External Male-Internal. Male External Sex Organs. The external sexual organs of the human male: Scrotum Testes P enis. Male External Sex Organs. Scrotum.
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Sexual Anatomy Female-External Female-Internal Male-External Male-Internal
Male External Sex Organs • The external sexual organs of the human male: • Scrotum • Testes • Penis
Scrotum • Defined: (Scrotal Sac) External pouch of skin beneath the penis that contains the testicles • Normally hangs loosely from a man’s abdominal wall • Directly beneath the penis. • Consists of Two Layers: • Outermost Layer: Covering of thin skin that usually is a darker color than other body skin. • Becomes sparsely covered with pubic heir during puberty • Second Layer: Composed of smooth muscle fibers and connective tissue.
Scrotum • Scrotum’s primary function is to maintain the temperature at which the testes most effectively produce sperm. • Average scrotal temperature is lower than body temperature by approximately 3.1 degrees Centigrade (5.6 degrees Fahrenheit). • Keeping the testes outside the body cavity keeps them cool and assures maximum sperm production. • As the temperature of the testes rises sperm production decreases. • Men are advised to wear boxer shorts if they are having trouble conceiving. • Relatively few nerve endings in the scrotum. • Some men find scrotal stimulating highly arousing. • When a male is “kicked in the balls,” the pain results from damage to the testes, not the scrotum.
Testes • Defined: Male reproductive organs within the scrotum. • Produce sperm. • Primary source of testosterone. • Within the scrotal sac: Two separate compartments: • Each houses a single testicle. • Each testis is suspended within the scrotum by the spermatic cord. • Spermatic Cord: Suspends the testes within the scrotum. • Contains- • Vas Deferens • Blood Vessels • Nerves • Fibers • CremastericMuscles (which influence the position of the testicle in the scrotal sac and are affected by temperature and sexual stimulation)
Testes • The testes can be contracted voluntarily: • Supposedly, some practitioners of Asian martial arts learn to retract the testes fully into the body cavity to protect them during combat. • Two Major Functions: • Secretion of sex hormones. • Production of sperm. • In most men the testes are asymmetrical (not the same shape and size). • Left testicle often hangs lower than the right since the left spermatic cord is longer than the right.
Penis • Defined: Male sexual organ • Two functions: • Passage of urine from the bladder to the exterior. • Passage of sperm from the testes to the exterior. Divided into three major areas: • Glans:Located at the tip of the penis. • Shaft: Body of the penis. • Root: Portion of the shaft that extends internally and is attached to the pelvic bones.
Penis • Prepuce: (Foreskin) Skin that covers the glans of an uncircumcised penis. The shaft of the penis contains nerves, blood vessels, fibrous tissue, and three parallel cylinders of spongy tissue: • Corpus Spongiosum: (Spongy body) Structure at the base of the penis that extends up into the shaft and forms the penile glans. • Urethra: Runs through the middle of the corpus spongiosum. • Urine and sperm pass through the urethra and exit at the urethral meatus, the uninary opening of the glans. • Corpora Cavernosa: (Cavernous Bodies) Structures in the shaft of the penis that engorge with blood during sexual arousal. • Run along the top of the shaft.
Penis • To accomplish the penises second function the penis must stiffen or become erect: • Accomplished by a sudden influx of blood into the corpus spongiosum and the corpora cavernosa. • At the root of the penis, the corpora cavernosa branch into tips called crurathat are attached to the pelvic bones. • Walruses have bone’s in their penises that are associated with erections. • Extensive network of muscles at the base of the penis, but the penis itself does not contain much muscle tissue
Penis • Reaches adult proportions at approximately 15 years of age. • Interesting: Some people believe that you can predict penis length by a man’s height or shoe size. • Neither body height nor foot size serve as practical estimators of penis length.
Male Genital Cutting • Circumcision - Surgical cutting away or removal of foreskin. • Supercision - Making a slit in the length of the foreskin on the top. • Subincision - Making a slit on the lower side of the penis along its entire length.