a-short-review-of-histology

The Penis:

The penis consists of three cylindrical bodies of erectile tissue
They are known as cavernous bodies
Each cavernous body is enclosed within a dense connective tissue sheath
The cavernous bodies are held together by connective tissue containing elastic fibres, overlain with thin skin
Each cavernous body consists of endothelial lined spaces between connective tissue trabeculae
The penis contains numerous sensory receptors associated with sexual arousal as well as a rich motor nerve supply to control the mechanism of erection
Helicine arteries, with both circular and longitudinal layers of smooth muscle cells in their walls, supply blood to the vascular spaces of the cavernous bodies
Parasympathetic nerves stimulate dilatation of the helicine arteries to allow blood to flow into the vascular spaces and cause erection
The resting tone (sympathetic control) of the muscular walls of the helicine arteries causes constriction of the helicine arteries and prevents blood flow into the vascular spaces to maintain the penis in a flaccid state

Diagrams of The Penis: