What is normal penis anatomy? The penis contains two chambers, called the corpora cavernosa, which run the length of the upper side of the penis (see figure 1 below). The urethra, which is the channel for urine and ejaculate, runs along the underside of the corpora cavernosa. Filling the corpora cavernosa is a spongy tissue consisting of smooth muscles, fibrous tissues, spaces, veins, and arteries. A membrane, called the tunica albuginea, surrounds the corpora cavernosa. Veins located in the tunica albuginea drain blood out of the penis. The pressure from the expanding penis compresses the veins (blood vessels that drain the blood out of the penis) in the tunica albuginea, helping to trap the blood in the corpora cavernosa, thereby sustaining erection. Erection is reversed when cGMP levels in the corpora cavernosa fall, causing the smooth muscles of the corpora cavernosa to contract, stopping the inflow of blood and opening veins that drain blood away from the penis. The levels of the cGMP in the corpora cavernosa fall because it is destroyed by an enzyme called phosphodiesterase type 5 (PDE5). Penile erection is managed by two mechanisms: the reflex erection, which is achieved by directly touching the penile shaft, and 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 the 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. Viagra canda safe to order generic viagra online buy viagra online
Blood hemoglobin A 1c: Abnormally high levels of blood hemoglobin A 1c in patients with diabetes mellitus establish that there is poor control of blood glucose levels. Who should not use vardenafil (Levitra)? Vardenafil (Levitra) can cause hypotension (abnormally low blood pressure, which can lead to fainting and even shock) when given to patients who are taking nitrates. People taking nitrates daily should not take vardenafil. Most commonly used nitrates are medications to relieve angina (chest pain due to insufficient blood supply to heart muscle because of narrowing of the coronary arteries). These include nitroglycerine tablets, patches, ointments, sprays, pastes, and isosorbide dinitrate and isosorbide mononitrate. Other nitrates such as amyl nitrate and butyl nitrate are found in some recreational drugs called "poppers." Surgery for erectile dysfunction. Implantable devices, known as prostheses, can cause erections in many men with impotence. Malleable implants usually consist of paired rods, which are inserted surgically into the corpora cavernosa, the twin chambers running the length of the penis. The user manually adjusts the position of the penis and, therefore, the rods. Adjustment does not affect the width or length of the penis. cialis online dove comprare cialis online
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The risk of developing heart attacks or abnormal heart rhythms during sex is low in men with well-controlled hypertension, mild disease of the heart valves, well-controlled heart failure, mild and stable angina (with a favorable treadmill stress test), successful coronary stenting or bypass surgery, and a remote history of heart attack (more than eight weeks previously). Sildenafil can be used safely in men in these low-risk groups.