Live~NRGY

Physiology of Penile Erection and Pathophysiology of Erectile Dysfunction

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1351051/

….In 1999, Stoleru et al. studied eight healthy right-handed heterosexual males with PET during visually evoked sexual arousal.24 Regions of brain activation were correlated with testosterone plasma levels and penile tumescence. Significant activation during visual evoked sexual arousal was seen in bilateral inferior temporal cortex, right insula, right inferior frontal cortex, and left anterior cingulate cortex. From this landmark study a tentative model for brain function during sexual arousal was introduced. The model suggests that there are three components of visually evoked sexual arousal associated with their neuroanatomical regions: 1) a perceptual-cognitive component – assesses the visual stimuli as sexual performed in bilateral inferior temporal cortex, 2) a emotional/motivational component – processes sensory information with motivational states performed in the right insula, right inferior frontal cortex and left cingulate cortex (paralimbic areas), 3) a physiological component – coordinates the endocrine and autonomic functions in the left anterior cingulate cortex….

Postganglionic nerve fibers – http://en.wikipedia.org/wiki/Postganglionic

Neurotransmitters

The neurotransmitters of postganglionic fibers differ:

In the parasympathetic division, neurons are cholinergic (that is, acetylcholine is the primary neurotransmitter.)

In the sympathetic division, neurons are mostly adrenergic (that is, epinephrine and norepinephrine function as the primary neurotransmitters.) One exception to this rule is the sympathetic innervation of sweat glands, where acetylcholine is the neurotransmitter at both pre and post ganglionic synapses. Another exception is the sympathetic innervation of the medulla of the adrenal glands, which is accomplished by preganglionic fibers, and subsequently uses acetylcholine as a neurotransmitter. The cells of the adrenal medulla are actually modified postganglionic neurons which secrete epinephrine and norepinephrine directly into the blood stream rather than into a synapse.[1]…