An erection (clinically: erect penis or penis tumescence ) is a physiological phenomenon in which the penis becomes hard, enlarged, and enlarged. Penile erection is the result of complex interactions of psychological, neurological, vascular, and endocrine factors, and is often associated with sexual arousal or sexual attraction, although erections can also be spontaneous. The shape, angle, and direction of erection vary greatly in humans.
Physiologically, erection is triggered by the parasympathetic division of the autonomic nervous system, causing nitric oxide (vasodilator) levels to rise in the trabecular artery and penile smooth muscle. The dilated artery causes the corpora cavernosa penis (and to a lesser extent corpora spongiosa) to be filled with blood; at the same time the muscles of ischiocavernosus and bulbospongiosus suppress the corpus cavernous veins limiting the way out and this blood circulation. Erection subsides when parasympathetic activity decreases to the baseline.
In response to the autonomic nervous system, erections can result from various stimuli, including sexual arousal and sexual arousal, and are therefore not entirely under conscious control. Erection during sleep or waking is known as nocturnal penile tumescence (NPT). The absence of a nocturnal erection is usually used to distinguish between physical and psychological causes of erectile dysfunction and impotence.
A partially, but not entirely, erection penis is sometimes known as semi-erect (clinically: partial tumescence ); an erect penis usually referred to as soft, or soft.
Video Erection
Physiology
Erection occurs when two tubular structures, called corpora cavernosa, which run the length of the penis, become enlarged with venous blood. This may be the result of various physiological stimuli, also known as sexual arousal and sexual arousal. Corpus spongiosum is a single tubular structure located just below the corpora cavernosa, which contains the urethra, through which urine and semen flow during urination and ejaculation. It may also become slightly enlarged with blood, but less than the corpora cavernosa.
The scrotum may, but not always, be tight during an erection. In general, the foreskin automatically and gradually pull back, exposing the glands, although some men may have to pull the foreskin manually.
Autonomous control
In the face of mechanical stimulation, erection begins with the parasympathetic division of the autonomic nervous system with minimal input from the central nervous system. Parasympathetic branches develop from the sacral plexus to the arteries that supply erectile tissue; in stimulation, this nerve branch releases acetylcholine, which in turn causes the release of nitric oxide from endothelial cells in the trabecular artery. Nitric oxide diffuses into the smooth muscle of the arteries (called trabecular plain muscle ), acting as a vasodilating agent. The arteries dilate, filling corpora spongiosa and cavernosa with blood. The muscles of ischiocavernosus and bulbospongiosus also suppress the corpora cavernosa veins, limiting the drainage of the blood vein. Erection subsides when parasympathetic stimulation is stopped; basic stimulation of the sympathetic division of the autonomic nervous system causes constriction of the penis arteries, forcing blood out of erectile tissue.
After ejaculation or cessation of stimulation, the erection usually subsides, but the time required may vary depending on the length and thickness of the penis.
Voluntary and accidental control
The cerebral cortex can initiate an erection without direct mechanical stimulation (in response to visual, auditory, olfactory, shadow, or touch stimuli) that work through erection centers in the lumbar and sacral areas of the spinal cord. The cortex can suppress an erection, even in the presence of mechanical stimulation, as well as psychological, emotional, and other environmental factors.
Nocturnal erection
Penis can erect during sleep or erect when waking up. Such an erection is medically known as nocturnal penis enlargement (informal: morning or morning glory ).
Maps Erection
Socio-sexual aspects
Social
Erection is a common indicator of sexual arousal and is necessary for men to affect vaginal penetration and sexual intercourse.
Erections commonly occur in children and infants, and even before birth. After reaching puberty, an erection occurs much more often. Plethysmograph penis that measures erection has been used by some governments and courts of law to measure sexual orientation. Unusual reluctance to the erect penis is sometimes referred to as phallophobia.
Spontaneous or random errors
Spontaneous erection, also known as involuntary, random or undesirable erection, is common and is a normal part of male physiology. Socially, such erections can be embarrassing if they happen in public or when they are unwanted. Erections can occur spontaneously at any time of the day, and if worn can cause a bulge that (if required) can be disguised or hidden by wearing tight underwear, long shirts, or baggier clothing.
Size
The length of a flabby penis does not have to match the length of the penis during erection; some of the smaller flaccid penises grow longer, while some of the larger flaccid penises grow relatively less. In general, erect penis size is improved throughout the post puberty period. The size can be increased by surgery, although penile enlargement is controversial, and the majority of men are "not satisfied" with the results, according to one study.
Directions
Although many penises are upright pointing upwards, it is common and normal for an erect penis to point almost vertically up or almost vertically downward or even horizontally straight forward, all depending on the suspensory suspension ligament that holds it in position. The erect penis can also take a number of different shapes, from a tube straight to a tube with curvature up or down or left or right. Increased penile curvature can be caused by Peyronie's disease. This can cause physical and psychological effects for the affected individual, which may include erectile dysfunction or pain during erection. Treatments include oral medications (such as colchicine) or surgery, most commonly used as a last resort.
The following table shows how various angles of erection are common for men standing. In the table, zero degrees (0 Â °) points straight toward the abdomen, 90 degrees horizontally and pointed straight ahead, while 180 degrees will point straight down to the foot. Angle pointing up is the most common.
Medical condition
Erectile dysfunction
Erectile dysfunction (also known as ED or "male impotence") is a sexual dysfunction characterized by an inability to develop and/or maintain an erection. The study of erectile dysfunction in medicine is known as andrology, a subfield of urology.
Erectile dysfunction occurs for many reasons. Please see below and also see separate entries on erectile dysfunction and references therein. Ultimately, the cause of erectile dysfunction is that not enough Nitrous Oxide (NO) is released by the vascular endothelium of the perineal artery branches, the branch of the internal pudendal artery.
Erectile dysfunction can occur due to physiological and psychological reasons, most of which can receive treatment. Common physiological reasons include diabetes, kidney disease, chronic alcoholism, multiple sclerosis, atherosclerosis, vascular disease, and neurological disease that collectively account for about 70 percent of ED cases. Some medications used to treat other conditions, such as lithium and paroxetine, can cause erectile dysfunction.
Erectile dysfunction, tied closely to the notion of potential culture, success and masculinity, can have devastating psychological consequences including feelings of shame, loss or inability; There is a strong culture of silence and an inability to discuss this issue. In fact, about one in ten men will experience repetitive impotence problems at some point in their lives.
Priapism
Priapism is a painful condition in which the penis does not return to a soft state, despite the absence of physical and psychological stimulation. The four-hour preemption is a medical emergency.
In non-human animals
At the time of penetration, the canine penis is not erect, and is only able to penetrate the female because it includes a narrow bone called baculum, a feature of placental mammals. Once a man reaches penetration, he will often hold the woman tighter and push faster, and that's when the man's penis expands. Unlike human sexual intercourse, in which the male penis generally becomes erect before entering the female, the intercourse of the dog involves the first male penetrating the woman, after the penile swelling for an erection occurs.
The elephant's penis is S-shaped when fully erect and has a Y-shaped hole.
Given the small amount of erectile tissue in the bull's penis, there is a slight enlargement after an erection. The penis is very stiff when not erect, and becomes more rigid during an erection. Projection is not much affected by erection, but rather by relaxation of penis retractor muscles and straightening of the bending sigmoid.
The fossa male penis reaches between his forelegs during an erection.
When not erect, the horse penis is placed in a prepuce, 50cm (20 inches) long and 2.5 to 6cm (0.98 to 2.36 inches) with a distal end of 15 to 20cm (5.9 to 7.9 inches ). Contraction of the retractor muscle to retract the penis into the sheath and relaxes to allow the penis to extend from the sheath. When erect, the penis doubles the length and thickness and the gland increases by 3 to 4 times . Erections and bulges occur gradually, with increased enlargement of erectile vessel tissue in the penis corpus cavernosum . Most stallions achieve an erection within 2 minutes after contact with estrus mare, and climb estrus mare 5-10 seconds thereafter.
The bird penis differs in the structure of the mammalian penis, into an erection of cloacal wall erection and established by lymph nodes, not blood. The penis of a lake duck can reach almost the same length as the animal itself when fully erect, but more commonly about half the length of the bird.
Terminology
Clinically, erections are often known as "erect penis", and the state becomes erect, and the erection process, described as "tumescence" or "penile tumescence". The term to abolish or terminate the erection is "detumescence".
Everyday language and in slang, erection is known by many informal terms. English terms that often encountered include 'stiff', 'hard', 'stupid' and 'woody'. There are some slang words, euphemisms and synonyms for erection in English and in other languages.
- WikiSaurus entries
See also
- Erection of the clitoris
- Death erection
- Erectores pilorum
- Issues in social nudity
- Nipple
- Nocturnal penile tumescence
- Priapism
- Sexual function
- The human penis
References
Source of the article : Wikipedia
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