Stop using Cialis and get emergency medical help if you have: erection is painful or lasts longer than 4 hours (prolonged erection can damage the penis); vision changes or sudden vision loss; or. heart attack symptoms - chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating.
For example, we now know that several areas in the brainstem and hypothalamus promote wakefulness by sending arousal signals to the cerebral cortex, the brainâs largest region. These signals come in the form of chemicals called neurotransmitters. When neurons in the arousal areas are active, the cortex remains activated and we stay awake. One area of the brain that promotes arousal is the tuberomammillary nucleus (TMN). Here, neurons release histamine as one of their neurotransmitters. Interestingly, many  anti-histamine  medicines block this arousing signal and cause sleepiness.
But, the brain-body response where sex and female sexual desire are concerned is more complicated than just thinking of the brain as a sexual organ.. First of all, as you know, the brain is the center of all our emotions and thoughts. It also is the operating center for a complex network of neurotransmitters and neuroendocrine systemsânerves, and other chemicals that are responsible for, among other things, sexual desire and response. For example, the brain transmits signals that start a cascade of reactions leading to genital arousal.