It is interesting that half the world's population has to deal with this amazing and equally quite disturbing situation every morning. What's the reason men wake up in the morning with erections?
Morning erections, or more scientifically known as "nocturnal penile tumescence" (nocturnal Penile Tumescence - NPT), are spontaneous erections that occur during sleep or close to waking. All men experience it except men with erectile dysfunction disorder. Even men who are not sick get an erection 3-5 times during the night!
Even NPT begins in the womb (in utero) and continues throughout life! We're not kidding: men get erections even on their mother's stomach! But men are actually not alone in this. Females also experience clitoral erection and vaginal bloating during sleep. Of course, as you can imagine, humans are not the only animal species living in NPT. In many known mammalian animals, the same condition occurs.
Although several different theories have been developed to explain the causes of NPT in the years we have left behind, the exact cause is still unknown. Just like clitoral erections, NPT is associated with REM sleep, where rapid eye movements are observed. One of the theories developed is based on the shutdown of noradrenergic cells (which are nerve cells that secrete the neurochemical noradrenaline) during REM sleep, called locus coeruleus. These cells are thought to be associated with reducing the amount of contraction of the penis; therefore, when their activity decreases during REM sleep, penis stimulation based on testosterone acts more than usual, causing the penis to swell.
It has been suggested that NPT is also related to the secretion of the chemical nitric oxide (no). NO is secreted from cells located in the inner part of blood vessels and after secretion goes to smooth muscles. This allows the muscles to relax. But it also causes blood vessels to expand, so more blood goes to the penis, and here's an erection! Increased activity of parts of the brain's pons region during REM sleep triggers a series of chemical events, eventually causing the secretion of no. All these chemical events are also again controlled by androgen (masculinity) hormones such as testosterone.
All right, so far we've talked about how it happened. But why? One of the reasons put forward is that these "penis exercises" during sleep actually contribute to the function of your penis. These sleep erections cause erectile tissue called corpora cavernosa to swell, and thus this tissue is liberally oxygenated. Thanks to this oxygenation, it retains its vitality and prevents a disease called cavernous fibrosis. This disease is a condition that eventually leads to penis dysfunction.
One of the other intriguing reasons put forward on the subject is that these erections prevent men from wetting their bottoms. Because there are 2 types of male erections: psychogenic and reflexive. The first occurs as a result of stimulation of nerves due to sexual thoughts and images. I mean, we can call it" the erection we know." The latter can occur involuntarily, even without having sexual thoughts, and its main cause is thought to be a full bladder. The nerves that control such reflexive erections are a part of the spinal cord called the sacral nerves. The same nerves are also stimulated when your urine bag is full. Because urinating with a bulging penis is difficult, NPT is thought to preclude "bed-wetting," known in science as "involuntary night urine." Although this may sound plausible, it is actually a fairly unlikely explanation, because our bodies have too many mechanisms that prevent us from wetting our bottoms. Moreover, the fact that the same erections are also found in females makes no sense in terms of this explanation.
So the most logical explanation so far is that their enthusiasm tonight has evolved because it provides protection to penises. Imagine: your penis thinks of itself for you!