S EXUAL A NATOMY o Female-External o Female-Internal o Male-External o Male-Internal

M ALE E XTERNAL S EX O RGANS The external sexual organs of the human male: Scrotum Testes Penis

M ALE E XTERNAL S EX O RGANS

S CROTUM 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.

S CROTUM 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.

T ESTES 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 Cremasteric Muscles (which influence the position of the testicle in the scrotal sac and are affected by temperature and sexual stimulation)

T ESTES 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.

M ALE E XTERNAL S EX O RGANS

P ENIS 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.

P ENIS 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.

P ENIS 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 crura that 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

P ENIS 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.

M ALE G ENITAL C UTTING 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.