The head of the penis ( Latin glans penis [1] ) - the front part of the penis, covered with foreskin [2] .
The head of the penis is the end part of the penis , formed by the expanding end of its spongy body , serving as its outer end, and having the shape of a blunt cone with a rounded tip [3] [4] [5] . The overhanging part of the base of the head is called the “rim” [3] .
Through the head, the male urethra , which ends in its external opening, passes through the head, through which both urination (with unexcited condition of the penis) and eruption of seminal fluid, necessary for fertilization of female germ cells with the purpose of procreation, occurs in men. The head contains a large number of nerve endings, which makes it extremely sensitive to touch and, accordingly, the main male erogenous zone , responsible for the reflex achievement of the moment of ejaculation.
From birth, the male head is covered with skin folds of the foreskin and can usually be bare only after reaching puberty. The inner sheet of the foreskin is rich in moisturizing the segmental glands that they produce with the smegma . On the underside of the penis, the foreskin is attached to the head with a bridle , which is tightened during the abduction of the foreskin by the head.
In women, the head of the male penis genetically and partly structurally corresponds (homologous) is usually the much smaller head of the female genital organ - the clitoris , also covered with its foreskin and attached to it by the bridle . However, besides usually many times smaller sizes, which make it often difficult to see, the clitoris differs from the male penis by the absence of the urethra passing through it and, accordingly, by the absence of holes in the clitoris head. The female urethra, wider and shorter than the male, has its external opening behind the clitoris and before entering the vagina , on the eve of it , hidden by the small and large labia , and not placed on the top of the organ.
Content
Anatomy and physiology of the head and adjacent structures
The head has approximately the shape of a cone with a rounded apex or hemisphere, having an extension below.
The lower edge of the head, the nimbus, is wider than the body of the penis at the site of their fusion, and under the nimbus, the narrowing of the body of the penis forms the coronal sulcus. It is its growth when articulated with the cavernous bodies of the body of the penis. The corolla and coronary sulcus have the highest sensitivity in the male body to mechanical erogenous stimuli and the corolla often serves as the main source of male sensations during intercourse during friction against the vaginal wall of a woman , which are necessary for a reflex to achieve orgasm with the release of seminal fluid, which ensures fertilization of the egg in the cavity female internal genital organs.
The coronary sulcus has a ring-shaped form and serves as a place of attachment of an elastic protective skin of the penis. The part of this skin tube that is furthest from the body of the man and is attached to the coronary sulcus is called the foreskin of the penis. Outside the sexual arousal phase, the foreskin hangs loosely, covering the head of the penis with its inner leaf to protect it from damage and sometimes extending over various short distances beyond the outer end of the head and thereby protecting the external opening of the urethra. It covers the opening from the sides, but usually does not close it, although, due to its mobility, it can move sideways and deflect the urine stream coming out of it.
The penis consists of elastic in a calm state and capable of filling with blood for an erection of longitudinally cavernous and spongy bodies located in it. They form his trunk, covered with leather outside. Most of the trunk thickness is formed by cavernous bodies, between which from the bottom side there is a spongy body, inside which passes the urethra. The trunk of the penis ends with a head into which its spongy body passes. Accordingly, like the trunk, the head is capable of filling with erection, in which it also increases in size.
Normally, on the top of the head there is an external opening of the urethra (urethra). It is a small vertical slot, covered with equally small elastic protrusions - sponges. They reflexively move apart during urination and ejaculation and can be diluted a little distance from the outside if medical personnel need to introduce into the urethra diagnostic examination tools of its lumen and bladder cavity (cystoscope device for cystoscopy ), as well as a catheter for emptying the bladder in cases of impossibility of its natural emptying during the growth of the prostate gland adenoma squeezing it or specific lesions of the part of the spinal cord that controls the slave from the pelvic organs (catheterization of the bladder). In case of congenital developmental disorders, the external opening of the male urethra may not be at the top of the head ( hypospadias ), but during epispadias, the wall of the channel itself may be more or less split, and the head itself may be split to some extent or all. penis.
The cross-section of the head is not perfectly round, since a longitudinal groove is inserted into its lower surface. The seam formed by the sulcus runs along the entire body of the penis and continues on the scrotum. The furrow and suture occur during embryonic development during the overgrowth of the urogenital furrow (cleft), characteristic of the embryo to the stage of its sexual differentiation, thus not overgrowing in the embryos, which in the following stages will develop along the female type, and will turn into the sex gap containing the eve of the vagina , surrounded from the sides by pairs of small and large labia. Greater than usual non-growth of this furrow in males and is epispadias or hypospadias.
Sexual head physiology
The head with an erection is less resilient than the body of the penis itself, which reduces the risk of injury to the female genital organs during sexual contact . In addition, the head is always more sensitive than the rest of the penis, as it is rich in nerve endings. The most sensitive part of it is the crown (crown).
In the lower part of the glans head, there is a bridle , which during intercourse pulls the head down so that its crown comes into contact (rubs) with the walls of the vagina, exciting the nerve endings in the crown (crown) and the nerve endings of the vagina. The urethra and ejaculatory canal enters the head of the penis in the form of a small gap from 3 to 5 mm.
The head of the penis is penetrated by glands that keep its surface moist.
The head is the most sensitive erogenous zone in men, and most often it is the attainment by its nerve endings of the excitation limit that serves as a reflex signal for ejaculation, which completes the active part of sexual intercourse. If ejaculation occurs too quickly (especially before the introduction of the penis), then experts can talk about premature ejaculation. To eliminate this problem, various medical technologies are used, in particular, to reduce the sensitivity of the head. For example, its exposure to non-sexual intercourse. After exposure, it will often be exposed to environmental influences. A radical means of such exposure is the circumcision of the foreskin, a more moderate means of moving the foreskin by the head and holding it there with special retractor rings held by the head rim in the coronal sulcus. However, physiological by nature is the cover of the head with the foreskin to moisten it and protect it from injury.
Female head homologue
In women, the head of the penis corresponds in its genesis, shape and richness with sensitive nerve endings for the implementation of the erogenous function of the head of the female penis - the clitoris , which normally has much smaller sizes than the penis. In most cases, this is the only part of the clitoris itself that is visible from the outside, whose body is hidden in the pubic joint. With sexual arousal, it, like the entire clitoris, swells and is extremely sensitive to touch. It is also covered to varying degrees by its protective fold of skin — the foreskin of the clitoris — and is connected to it by a bridle .
Hygiene of the head and foreskin
Until puberty, the foreskin is usually not separated from the head of the penis. Upon reaching puberty between the foreskin and the head in the area of the coronary groove separating the head from the body of the penis appear viscous whitish discharge - smegma , serving as lubricant and moisturizing to protect the sensitive area of the body from drying out and irritation. However, their accumulation can lead to an unpleasant odor and the formation of an environment for the reproduction of pathogenic bacteria that cause inflammation, therefore, among other hygienic procedures, regular removal of the smegma with cleansing the head and foreskin by washing the smegma and / or wiping the surfaces with male intimate hygiene is required. It becomes possible when the skin of the penis is retracted with the foreskin back to completely expose the head. The history of medicine suggests that, because in a desert hot climate with its inherent lack of water for ablution in the peoples of the countries of Western Asia, such inflammations could occur frequently, and their causes and methods of prevention were not obvious, it was for their prevention in the religions that arose there (Judaism and then Islam) was introduced circumcision, after which the head of the penis is constantly exposed and smegma has no opportunity to quietly accumulate in the surrounding recess. For hygienic reasons, circumcision has been practiced outside of these religions, especially in the United States of America. Nevertheless, the nature of the foreskin is not superfluous, since it serves to protect the easily injured glans penis from external exposure and, if the hygienic norms are observed, inflammation in this zone can be avoided.
Pathological conditions of the glans penis
Like other organs, pathological conditions here can be congenital and acquired, acute and chronic, infectious-inflammatory and non-infectious (for example, developmental disorders).
Disorders of development and inflammation associated with the condition of this organ, and the surrounding organs and tissues. Thus, inflammatory diseases of the head are often accompanied by inflammation of the surrounding foreskin, which can be caused by anomalous narrowing of the latter, making it difficult to remove smegma and urine residue from the gap between them.
- Phimosis is a narrowing of the foreskin, in which the head of the penis does not open at all or causes pain.
- Balanitis - inflammation of the skin of the head of the penis.
- Pearlescent papules are a non-pathological feature of the structure.
- Epispadias - partial or complete splitting of the anterior wall of the urethra .
- Hypospadias - the location of the external opening of the urethra is not on the top of the glans penis, but on its lateral surface.
Notes
- ↑ Oxford English Dictionary 2nd edition, 1989
- ↑ Akayevsky, A.I. Anatomy of Pets. - Kolos, 1975. - p. 328. - 590 p.
- ↑ 1 2 Penis // Big Medical Encyclopedia.
- ↑ Genital Head // Medical Dictionary.
- ↑ Head of the penis // Big Medical Dictionary.
Literature
- Halata, Zdenek; A. Spaethe. Sensory innervation of the human penis (Eng.) // Advances in Experimental Medicine and Biology : journal. - Springer Nature , 1997. - Vol. Advances in Experimental Medicine and Biology . - P. 265-266 . - ISBN 978-0-306-45696-1 . - DOI : 10.1007 / 978-1-4615-5913-9_48 . - PMID 9361804 .
- Masters, William H. Human Sexual Response. - Boston: Little, Brown & Co, 1966. - P. 189–91. - ISBN 0-316-54987-8 . ( excerpts )
- Gallup, Gordon; Rebecca L. Burch; Mary L. Zappieri; Rizwan A. Parvez; Malinda L. Stockwell; Jennifer A. Davis. The human penis as a semen displacement device (Eng.) // Evolution and Human Behavior : journal. - 2003. - July ( vol. 24 , no. 4 ). - P. 277-289 . - DOI : 10.1016 / S1090-5138 (03) 00016-3 .