Erection occurs when the brain receives signals from the five senses sensual stimulation as well as from a dream, which then sends nerve signals to the penis tissues to react to that stimulus. Sensitivity varies erection levels in men. There are only seeing the picture she just had an erection, there also should be stimulated first for a new long can erection, and a more severe when they are stimulated not also capable of erection, it is called impotence.

Erection of a sound influenced by the following factors:
1. Physical Factors
• Drugs: drugs anti-hypertension, diuretic (stimulating the release of urine), sedation, weight loss, ulcer drugs, nicotine, alcohol affects the decline in erectile ability.
• Blood flow: blood flow is not smooth can also interfere with the ability of an erection. Diligent exercise to be one way for blood circulation. High cholesterol has the potential to inhibit the body's blood flow because of clogged blood vessels.
• Nerves: disturbances in the system to disrupt shipping persyarafan sensory and motor signals to the brain and spinal cord so that the signals that stimulate the sensual power does not reach the brain or the nerves penis so that erections do not occur.
• Hormones: hormonal disorders that cause a decline in testosterone levels also may decrease the ability of male erection.
• Illness: the illness may inhibit erection ability, apart from physical factors as well from psychological distress due to illness.

2. Psychological factors
• Depression: Depression makes him unable to relax and would inhibit sexual ability.
• Stress: especially the prolonged stress can weaken male sexual libido, because in his mind there was only the problems at hand. We recommend that you first eliminated until the mind relaxed.
• Anxiety: anxious about something also makes the mind is not calm. Fear of failure, haunted by feelings of guilt or shame will make him become tense and inhibit erections. If prolonged can lead to impotence.
• Wrong information about sex: the wrong perception about sexuality can make a man who experienced failure in bed, although quite new, will be stressed and worried about his ability. Men on average have a perception must always be excellent in bed.

Erection of a good measure of the level of violence erection. Dr. Bernard Herdinan Purba, SpRM, sexologists from RSCM justify it. "In general, men experience an erection. It's just that the level of violence prialah erection of a benchmark in improving the quality of better sex with a partner, "
(Http://www.resep.web.id/seputar-sex/kek erasan-male-erection-and-sex-satisfaction-wanita.htm)

Measuring Violence Erection - Tips from Dr. Naek L. Tobias, (http://www.inilah.com/berita/gaya-hidup/200 9/06/23/118705/ciri-ciri-ereksi-mr-dick-normal /)
Normal erection:
1. When Mr. Dick held or squeezed will feel hard.
2. Mr. Dick can not be bent because of stiff so it is often called a timber,
3. When shaken, Mr. Dick would shake and vibrate and then back to its original position.

Natural Erection
1. Erection Night
Erection is common when men sleep. Can occur due to increased hormone testosterone or nerve stimulation during the acquisition of a sensual dream. For teens usually can occur 8-9 times during the night but without realizing it because we were sleeping.
2. Morning Erection
Occurred because of two possibilities, the first increase in the hormone testosterone in the morning that stimulates the penis to stiffen. Both are full bladder while asleep, because the brain does not react to signals from the bladder, the nerve signals sent to the penis and stimulates for tense. Usually after urinating penis will return to normal slowly. But there also continue to masturbation or coitus with his wife in the morning.

Characteristic symptoms of Erectile Dysfunction:
1. Erection of morning began to diminish or even never erection morning in a long time.
2. Penis getting flabby and shrunken.
3. The penis could not last long when erect, or become soft quickly.

Causes of Erectile Dysfunction:
1. Stress
2. Lifestyle
3. Lack of exercise
4. Cigarette
5. Disease
6. Alcohol
7. Cholesterol

Erection Why Important?

"When a woman aroused, the vagina is shrinking. One third of the vagina outside the narrows, the enlarged two-thirds of the inside. When a woman gave birth, her vagina can be stretched. So do not determine the size of the penis. When a woman aroused, a third outer narrowing. Well, in There he takes good penile erection. " - Prof. Dr. Dr. Wimpie Pangkahila, Sp.And, FAACS
(Http://lifestyle.okezone.com/read/2009/ 08/19/24/249500/puaskan-wanita-dengan-ereksi-terhebat)

Drawn from various sources.