Organ
Penis
Coordinated erectile tissue, sensation and urethral transport
High-yield
Erection involves cavernous smooth-muscle relaxation and increased inflow. Emission is mainly sympathetic; subsequent expulsive contractions recruit pudendal somatic pathways.
Overview
The penis combines two corpora cavernosa with a corpus spongiosum surrounding the urethra. The root is attached to the perineum, the shaft extends outward and the spongiosum expands distally into the glans. Neural and vascular coordination permits erection and the passage of urine or semen.
Reference facts
- Location
- Root fixed to the pubic arch and perineal membrane, shaft anterior to the scrotum, and glans at the distal end.
- Parts
- Root comprises two crura and a bulb; shaft contains paired cavernosa and ventral spongiosum beneath connective-tissue and skin coverings.
- Blood supply
- Internal pudendal branches supply cavernosal, bulbar and dorsal territories, with regional arterial connections.
- Innervation
- Pudendal branches carry sensation and perineal motor output; cavernous autonomic nerves regulate erectile smooth muscle. Emission also involves sympathetic pelvic pathways.
- Venous/Lymphatic drainage
- Deep veins join pelvic plexuses and superficial veins join external pudendal routes. Lymphatic destinations vary between skin, glans, urethra and proximal erectile tissues.
- Relations
- Suspensory tissues connect the base to the pubic region; ischiocavernosus covers the crura and bulbospongiosus covers the bulb.
- Function
- Serves as an erectile organ and a conduit for the terminal urethra.
Mnemonic
Relax and fill for erection; move fluid for emission; contract perineal muscle for expulsion.
Clinical correlation
Cavernous nerves near the prostate can be injured during pelvic surgery, affecting erectile function. Recovery also depends on vascular health and other factors. Ischemic priapism typically produces rigid cavernosa with a relatively soft glans.
Frequently asked questions
Where is the penis located?
The penis lies root fixed to the pubic arch and perineal membrane, shaft anterior to the scrotum, and glans at the distal end.
What does the penis do?
Serves as an erectile organ and a conduit for the terminal urethra.
What are the parts of the penis?
Root comprises two crura and a bulb; shaft contains paired cavernosa and ventral spongiosum beneath connective-tissue and skin coverings.
What is the blood supply of the penis?
The penis is supplied by the internal pudendal branches supply cavernosal, bulbar and dorsal territories, with regional arterial connections.