Humor de Derechas

Penile erection is managed by two different mechanisms. The first one is the reflex erection, which is achieved by directly touching the penile shaft. The second is the psychogenic erection, which is achieved by erotic or emotional stimuli. The former uses the peripheral nerves and the lower parts of the spinal cord, whereas the latter uses the limbic system of the brain. In both conditions, an intact neural system is required for a successful and complete erection. Stimulation of penile shaft by the nervous system leads to the secretion of nitric oxide (NO), which causes the relaxation of smooth muscles of corpora cavernosa (the main erectile tissue of penis), and subsequently penile erection. Additionally, adequate levels of testosterone (produced by the testes) and an intact pituitary gland are required for the development of a healthy erectile system. As can be understood from the mechanisms of a normal erection, impotence may develop due to hormonal deficiency, disorders of the neural system, lack of adequate penile blood supply or psychological problems. Restriction of blood flow can arise from impaired endothelial function due to the usual causes associated with coronary artery disease, but can also be caused by prolonged exposure to bright light. I have bought viagra here generic viagra online without prescription looking for viagra ? canadian pharmacy viagra for sale Sildenafil is a potent inhibitor of PDE-5, the enzyme that acts in the corpora to break down cGMP. This action is mediated by the secondary neurotransmitter NO, which is primarily responsible for smooth muscle relaxation within the corpora cavernosa. The inhibition of PDE-5 slows the degradation of NO, which enhances its effect. This permits the development of an improved and sustainable erection. Physical Causes of Erectile Dysfunction