Sexual Anatomy Male-External
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. Consists of Two Layers: Outermost Layer: Covering of thin skin that usually is a darker color than other body skin. 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. As the temperature of the testes rises sperm production decreases. Relatively few nerve endings in the scrotum.
Testes Produce sperm. Primary source of testosterone. Two separate compartments: Each houses a single testicle. Left hangs lower than the right. ____________________________________________________________ Spermatic Cord: Suspends the testes within the scrotum. 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)
Penis 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. _______________________________________________________________ Shaft of penis: Corpus Spongiosum: 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. Corpora Cavernosa: Structures in the shaft of the penis that engorge with blood during sexual arousal. Run along the top of the shaft.
Male External Sex Organs
Penis Reaches adult proportions at approximately 15 years of age. Erection: Accomplished by a sudden influx of blood into the corpus spongiosum and the corpora cavernosa. Crura: Attach the penis to the pelvic bones. ____________________________________________________________ Average Penis Size: Flacid-3.5 inches Erect-5.1-5.9 inches 98% of the male population falls within this range-4.23-7.53 inches. The median penis size is smaller than the mean. (This means that most males are smaller than the average).
Penis Body Part Correlation Coefficient middle finger to palm distance 0.25 length of thumb length of big toe 0.18 shoe size 0.08
Penis