Modes Of Penile Erection

Penile erections are elicited by local sensory stimulation ofthe frenulum, glans penis, and perigenital skin (reflexic erections) as well as by central stimuli received by, or generated within, the brain (psychogenic erections). Both types of erectile mechanisms likely act in a synergistic manner and are controlled by the autonomic nervous system (see Fig. 6 Table 7). Reflexic erections are mediated by a spinal reflex pathway whereby sensory information from the penis and genitalia is...

Functional Vascular And Microscopic Anatomy Of Penile Erection

Colles Fascia Scrotum

Three spongy cylinders comprise the human penis the paired corpora cavernosa runs dorsolaterally and the corpus spongiosum runs ventrally. Incomplete septa between the corpora cavernosa allow for neurovascular communication, allowing the two bodies to function physiologically and pharmacologically as a single unit. The three corporal bodies are enveloped by a dense fascial structure known as the tunica albuginea. The deep fascia Buck's fascia ofthe penis surrounds the outside ofthe tunica...

Central Mechanisms Of Penile Erection And Flaccidity

The cortex receives sensory information from the penis and genitalia. Stimulation of thalamic and cortical areas associated with somatomotor pathways elicits sexual feelings and genital sensations but does not lead to penile erection. Conversely, stimulation of cortical-subcortical areas linked to the limbic system elicit penile erections in response to stimulation, as demonstrated in monkeys 5,171-173 . Direct study of the human brain is limited to observations made during neurosurgical...

Erectile Tissue

Penile Artery

Schematic representation of a cross-section of the human penis. Adapted from ref. 282. Fig. 2. Schematic representation of a cross-section of the penis that demonstrates the collagen skeleton of the penis. Adapted from ref. 283. Fig. 2. Schematic representation of a cross-section of the penis that demonstrates the collagen skeleton of the penis. Adapted from ref. 283. Tunica Albug nea and Fibrous Skeleton ofthe Penis The tunica albug nea is composed of elastic fibers forming a tough...

Functional Neuroanatomy Of Penile Function

Ischiocavernosus Erection

Parasympathetic and Nonadrenergic and Noncholinergic Outflow Parasympathetic preganglionic input to the human penis originates in the sacral S2-S4 spinal cord 30 . In most men, S3 is the main source of erectogenic fibers, with a smaller supply provided by either S2 or S4. These preganglionic neurons are situated in the intermediolateral cell column and send dendritic projections to laminae V, VII, IX, and X of the spinal cord. These distributions for axonal processes imply that sacral...