Anatomy, Abdomen and Pelvis, Penis

Excerpt

The penis is a male organ that is used for reproduction and urination which is located within the urogenital triangle between the perineal membrane superiorly and deep perineal fascia inferiorly. Its composition divides it into 3 parts: the glans, body, and root. Dorsally, it is composed of the paired corpora cavernosa and ventrally the corpus spongiosum which contains the urethra. The anatomical positions of the penis are according to the erect penis with the dorsal direction being closer to the head and ventral direction being closer to the feet. The tunica albuginea is a fibrous sheet which encapsulates the cavernous body. Buck's fascia, also known as deep fascia of the penis is superficial to the tunica albuginea and is the continuation of the deep perineal fascia which covers the corpora cavernosa and corpus spongiosum together. The spongy urethra is contained within the corpus spongiosum. The crura of the penis is between the 2 corpora cavernosa in the median plane externally. The corpora cavernosa is separated by the septum of the penis internally. The attachment of the penis consists of the bulb, crura, and ischiocavernosus and bulbospongiosus muscles, which collectively makes up the root of the penis. The bulb of the penis and crura contain erectile tissue. The middle portion of the penis is suspended and known as the body of the penis. The body of the penis lacks muscles and consists mostly of corpora cavernosa, corpus spongiosum, and spongy urethra with supporting skin, connective tissue, and blood, lymph, and fascia. The distal part of the penis is known as the glans penis. The proximal portion of the glans is termed the corona. The neck of the corona glans separates it from the body of the penis. The tip of the glans contains the opening to the urethra, known as the meatus. There is loose connective tissue between the thin skin of the penis and the tunica albuginea. The prepuce or foreskin is the second skin layer that covers the glans penis. The frenulum of the prepuce connects it to the urethral surface of the penis glans. The suspensory ligament of the penis is part of the deep fascia that arises from the anterior surface of the pubic symphysis. The fundiform ligament of the penis descends in the midline from the linea alba anterior to the pubic symphysis and splits to surround the penis and then unites and blends inferiorly with the dartos fascia forming the scrotal septum.