Sex on the Brain by Dr Jack Lewis

Hypothalamus’s PVN (red) prepares the body for sex by sending a torrent of electrical messages along neurons within the spinal cord which ultimately releases a cocktail of neurotransmitters into the genitals. In both men and women this leads to vasocongestion whereby the genitals become engorged with blood – leading to an erection in men and lubrication, increase in vaginal depth and diameter in women.