what is the main reason for erection during sextual stimulation?
88790
To be able to complete the job started from the stimulation.
579652
There are four stages in the human sex response.  Arousal, stimulation, orgasm, resolution.  In the male the first thing that must occur is arousal in which the penis becomes rigid or erect. At this point it is also more sensitive. Also a small amount of lubricant is excreted from the penis it is clear and slippery.  This is to help facilitate the insertion of the penis into the womans vagina. Next the penis is moved in and out of the vagina which results in stimulating the penis until orgasm.  This is the point when the glands and the muscles in the genital area contract and the fluid semen is expelled from the penis. This is ejaculation.  After ejaculation the male penis relaxes and becomes flaccid or soft again.  In young males arousal can be achieved in a short time minutes usually.  In older males several hours may have to pass before the penis can become erect.  A man may use his hand to provide stimulation thus having sex without a partner.  This is masturbation or solo sex.
252394
You are being stimulated by the vibration of the vehicle, thus causing the erection. It's nice to be young, eh?
1163464
your penis stands because your mind released nitrous oxide and it gorges your penis with blood like a balloon.  If you're not in the mood it's hard to get a hard on.  Also if you have sex all the time it's hard as well.  And the muscle that helps your erection is located between your sack and anus.  Press on it and you'll see your penis get a little bigger.  Try flexing it, and keep it in good shape.
1022295
Erection is a physiological process controlled by various neuroendocrinal and autonomic body function.It is controlled by parasympathetic nervous system which lead to vasodilation in vessels of corpora cavernosa that results in blood pooling in penis and hence produce erection.It is misconception that it occurs only during sexual arousal.its important for sexual functioning hence limbic system of brain do causes cascade of Nero endocrine changes to cause erection.limbic system may be activated by visual,auditory,touch sensation,smell or even just thought related to sexual feeling.but it can also occur without limbic system involvement(without sexual feeling) as it may be purely neural response.best example i can give is during REM sleep(dreamy sleep) or seizure activity.this is because of excessive autonomic neural discharges.special mention about pathological erection which is difficult to reversible is essential. it is usually due to vessels obstruction best example for it is sickle cell anaemia.
1076889
lots of veins there ,and it gives you an amazing erection.\n\n,i read that somewhere
492992
This is what the American Cancer Society states:\nAn erection occurs when the brain sends a signal down the spinal cord and through the nerves that sweep down into the pelvis. Some of these important nerves run along both sides of the prostate gland. \n\nWhen this signal is received, the spongy tissue inside the shaft of the penis relaxes and the arteries (blood vessels) that carry blood into the penis expand. As the walls of these blood vessels stretch, blood races into the penis at up to 50 times its usual speed. The blood fills 2 spongy tubes of tissue inside the shaft of the penis. The veins in the penis, which normally drain blood out of the penis, squeeze shut so that more blood stays inside. This causes a great increase in blood pressure inside the penis, which produces a firm erection.
624907
Try and think of something else.\n\nGet a doctor to help you, it could be pariapism, in case your erection doesn't go down, even when you are not thinking of sex.\n\nst
425333
The penis is made from a spongy tissue. When a male gets sexually excited, this tissue gets filled with blood and the penis hardens as a result.
457715
Several things can cause morning erections. One, as the bladder fills during the night, it tends to trigger a spinal reflex that can cause erection. Also, the congestion caused by the full bladder can decrease the outflow of blood from the penis. There are aspects of normal sleep cycling that tend to induce erection as well.
915078
There is a power drain when you get an erection.  This power drain takes a little time to build back up.  It is during these times when you see guys cutting fingers off with power tools, answering those stupid questions like "do i look fat in this", and talking incoherently when a women with nice totties and back side walks by!
418708
When a male becomes sexually aroused, blood flows into his penis making it erect, and thus ready for the act of sexual intercourse.
404786
Okay, I'm thinking back to my sex-ed classes but the stages are like desire, arousle, plateau, then orgasm.  If a guy sees something sexual, that can cause him to get aroused or get hard (ie an erection).  Forms of foreplay can do this to.  Kissing, touching.  That can all lead to arousle.  There is a pre-cum stage where some secretions come out but nothing huge yet.  I think a guy needs to be touched there, though, to experience orgasm and spilling their fluids (ejaculation).  Either with hands, mouth, or ahem...other areas.  Girls though, have their clitoris outside of their vaginal opening so that's usually all they need to achieve orgasm.  Hence vibrations, touching, smaller things can cause orgasm.  Personally, I like making out, but I need a much more hands-on approach to achieve orgasm.
884956
Erections are a result of blood engorging the penis therefore an interruption or lessening of blood flow results in a partial or complete loss of erection.  If what you really want to know if why blood flow would lessen, that's tough to say.  A vascular problem, distraction, loss of libido, erectile dysfunction, lack of arousal.  Pick one.
1170796
I would suggest a website such as Wikipedia for more information, as there are many causes and "cures" for it.\n\nIn brief, impotence is either physical or psychological. The way a penis becomes erect is a rush of blood to the organ, which then causes the penis to become rigid to aid during intercourse. Impotence is the condition when this blood does not stay in the penis for long enough, or the inability for any blood to get to the penis in the first place.\n\nPhysical\nIf the impotence is caused by a physical problem, then the cause can be disease or infection, a blockage of the veins, or some other restriction. The cure would be to provide medication or surgery to help the symptoms reverse.\n\nPsychological\nSometimes the problem is caused through the brain. Maybe the man does not feel up to it, is tired, or feels insecure. These and other similar reasons can impact on his ability to "perform". The way to cure this is to help the man through his emotional problems and allow him to feel safe and secure again.
102424
more foreplay, the longer you have an erection without sex, the more your buddy gets used to the feeling of being stiff.  During sex, don't just thrust til you spew, get a good rythm going, then ease it off, pay attention to her needs, then go back to thrusting, etc
2130
Yes, it can. the male erection is caused by increased blood flow to the genitals. If a person has high blood pressure, all his blood flow is problematic. this may cause sexual dysfunction.