Male genital organs - location, structure, functions. Male reproductive system
The male reproductive system is a fragile and very complex mechanism, the correct functioning of which is influenced by many factors. It consists of the following organs:
- two testicles;
- epididymis;
- vas deferens.
A man's testicles are paired endocrine glands that are responsible for the production of the male sex hormone. They are located in the scrotum and reach a length of 4-5 cm each. In parallel with the production of testosterone in the testicles, the maturation and development of male germ cells occurs. From the testicles, sperm move to the epididymis.
Each testicle has its own appendage, which is a long, spiral-shaped tube into which sperm from the testicle enter to undergo the final stage of maturation. The epididymis plays the role of a so-called “storage chamber” for sperm ready for fertilization until ejaculation, when the sperm enters the vas deferens.
The epididymis is connected to the urethra by the vas deferens, passing through which fully mature sperm are saturated with juice, which is necessary to maintain the life of sperm after they leave the male genital tract through the urethra.
The process of production and maturation of sperm - spermatogenesis - begins in a man from the moment of puberty and does not stop until the last days of his life. Spermatogenesis is regulated by various hormones, the production and ratio of which is controlled by the brain. As in women, the male pituitary gland produces luteinizing (LH) and follicle-stimulating (FSH) hormones, each of which has its own unique function in regulating the process of spermatogenesis.
Stimulates the production of the male sex hormone testosterone, due to which new male sex cells are formed. In addition, a man’s puberty, muscle mass gain, male-pattern hair growth, and much more depend on testosterone. in turn, is responsible for the further maturation of sperm and the production of healthy sperm by activating other hormones.
The process of formation, growth and full maturation of one sperm takes 72 days (several million sperm are released during ejaculation). The first 50 days are allotted for growth in the testicles, then the sperm begin to slowly move into the epididymis, where they fully mature, in addition, they have the ability to move in the epididymis. During ejaculation after sexual intercourse, sperm travel from the epididymis through the seminiferous tubules and urethra.
When seminal fluid enters a woman, sperm begin to actively move, trying to find the right path to the egg. And although only one male reproductive cell is needed for fertilization, the huge number of sperm that end up in a woman’s genital tract is justified. A woman's vagina has an acidic environment, which is necessary for natural protection against bacteria. But it can also have a negative effect on sperm, so while one part of the sperm goes to neutralize the acidic environment, the other can move through the cervix and enter the uterus, where the environment is more favorable.
Due to the fact that there are many cavities and convolutions in the female reproductive system, many sperm do not find the egg, which is located in one of the fallopian tubes. From the uterus, the remaining sperm - the strongest and hardiest - are sent to the fallopian tubes, where fertilization of the egg should occur by one of them.
The male reproductive system includes the scrotum, testes, seminal ducts, gonads and penis. These organs work together to produce sperm, male gametes, and other components of sperm. These organs also work together to carry sperm out of the body and into the vagina, where it will help fertilize the egg to produce offspring... [Read below]
[Start at the top] ... Scrotum
The scrotum is a bursa-like organ made of skin and muscle where the testes are located. It is located lower than the penis in the pubic area. The scrotum consists of 2 testicular sacs located side by side. The smooth muscles that make up the scrotum allow them to regulate the distance between the testes and the rest of the body. When the testicles become too warm to support spermatogenesis, the scrotum relaxes to move the testicles away from the heat sources. Conversely, the scrotum moves with the testes closer to the body when temperatures fall below the ideal range for spermatogenesis.
Testes
The 2 testes, also known as testes, are the male gonads responsible for the production of sperm and testosterone. The testes are ellipsoidal glandular organs about 4 to 5 cm in length and 3 cm in diameter. Each testis is located inside its own bursa on one side of the scrotum and is connected to the abdomen by the cord and cremaster muscle. Internally, the testes are divided into small compartments known as lobules. Each lobule contains a section of seminiferous tubules lined with epithelial cells. These epithelial cells contain many stem cells that divide and form sperm through the process of spermatogenesis.
Appendages
The epididymis is a sperm storage area that wraps around the superior and posterior edge of the testes. The appendage consists of several long, thin tubes that are tightly coiled into a small mass. Sperm are produced in the testicles and move to the epididymis to mature before being transferred through the male reproductive organs. The length of the epididymis delays the release of sperm and gives them time to mature.
Spermatic cords and vas deferens
In the scrotum, a pair of spermatic cords connect the testes to the abdominal cavity. The spermatic cord contains the vas deferens along with nerves, veins, arteries and lymphatic vessels that support the function of the testes.
The vas deferens is a muscular tube that carries sperm from the epididymis into the abdominal cavity into the ejaculatory canal. The vas deferens is wider in diameter than the epididymis and uses its internal space to store mature sperm. The smooth muscles of the walls of the vas deferens are used to move sperm to the ejaculatory duct through peristalsis.
Seminal vesicles
The seminal vesicles are a pair of lumpy exocrine glands that store and produce some of the liquid sperm. The seminal vesicles are about 5 cm in length and are located behind the bladder, closer to the rectum. The fluid in the seminal vesicles contains proteins and phlegm and has an alkaline pH to help sperm survive in the acidic environment of the vagina. The fluid also contains fructose to feed the sperm cells so they survive long enough to fertilize an egg.
Ejaculatory duct
The vas deferens passes through the prostate and joins the urethra in a structure known as the ejaculatory duct. The ejaculatory canal also contains canals from the seminal vesicles. During ejaculation, the ejaculatory duct opens and expels sperm and secretions from the seminal vesicles into the urethra.
Urethra
Sperm passes from the ejaculatory canal to the outside of the body through the urethra, a 20 to 25 cm long muscular tube. The urethra passes through the prostate and ends at the external opening of the urethra, located at the end of the penis. When urine leaves the body, the bladder, it passes through the urethra.
The walnut-sized prostate gland borders the lower end of the bladder and surrounds the urethra. The prostate produces most of the fluid that is sperm. This fluid is milky white and contains enzymes, proteins and other chemicals to support and protect the sperm during ejaculation. The prostate also contains smooth muscle tissue that can contract to prevent the flow of urine or semen.
Cooper's glands
Cooper's glands, also known as the bulbourethral glands, are a pair of pea-shaped exocrine glands located below the prostate gland and up to the anus. Cooper's glands secrete a thin, alkaline fluid into the urethra, which lubricates the urethra and neutralizes acid from the urine that remains in the urethra after urination. This fluid enters the urethra during sexual arousal before ejaculation to prepare the urethra for the flow of sperm.
Penis
The penis is the male external reproductive organ, located above the scrotum and below the navel. The penis is roughly cylindrical in shape and contains the urethra and the external opening of the urethra. Large pockets of erectile tissue in the penis allow it to fill with blood and become erect. Excitement of the penis leads to its increase in size. The function of the penis is to deliver sperm to the vagina during sexual intercourse. In addition to its reproductive function, the penis also allows the release of urine through the urethra to the outside of the body.
Sperm
Sperm is a fluid produced by males for sexual reproduction and ejected from the body during sexual intercourse. Semen contains sperm, the male sex gametes, along with a number of chemicals suspended in a liquid medium. The chemical composition of semen gives it a thick, sticky consistency and a slightly alkaline pH. These traits help sperm maintain reproduction by helping sperm remain in the vagina after sexual intercourse and to neutralize the acidic environment of the vagina. In healthy adult men, semen contains about 100 million sperm per milliliter. These sperm cells fertilize the oocytes inside the female fallopian tubes.
Spermatogenesis
Spermatogenesis is the process of sperm production that occurs in the testicles and epididymis of adult males. Before the onset of puberty, there is no spermatogenesis due to the absence of hormonal triggers. During puberty, spermatogenesis begins when enough luteinizing hormone (LH) and follicle-stimulating hormone (FSH) are produced. LH initiates the production of testosterone by the testes, while FSH causes the maturation of germ cells. Testosterone stimulates stem cells in the testicles known as spermatogonia. Each diploid spermatocyte goes through the process of meiosis I and splits into 2 haploid secondary spermatocytes. Secondary spermatocytes progress through meiosis II to form 4 haploid spermatid cells. Spermatid cells go through a process known as spermatogenesis, where they grow a flagellum and develop a sperm head structure. After spermatogenesis, the cell finally turns into sperm. The sperm are released into the epididymis, where they complete their maturation and become capable of moving on their own.
Fertilization
Fertilization is the process by which a sperm unites with an oocyte or egg to become a fertilized zygote. Sperms released during ejaculation must first swim through the vagina and uterus into the fallopian tubes, where they can find an egg. Upon encountering the egg, the sperm must penetrate the layers of the oocyte. Sperm contain enzymes in the acrosomal region of the head, which allows them to penetrate these layers. Once inside the oocyte, the nuclei of these cells fuse to form a diploid cell known as a zygote. The zygote cell begins cell division to form an embryo.
Over the course of a woman's life, she produces about 500 thousand eggs. Spermatozoa make up about 10% of the seminal fluid.
The male genital organs (organa genitalia masculina) are divided into internal (testis, epididymis, vas deferens, seminal vesicle, prostate and bulbourethral glands) and external (penis, scrotum).
Testicle (testis- lat.;orchis, didymis- Greek)- a paired organ that produces sperm and male sex hormones; located in the scrotum. It has an ovoid shape, somewhat flattened in diameter; The upper and lower ends, the outer and inner surfaces, the anterior and posterior edges are distinguished; along the latter, the epididymis is adjacent to the testicle. The surface is covered with a tunica albuginea formed by connective tissue, from which an ingrowth into the organ is formed along the posterior edge - the mediastinum of the testicle. Thin connective tissue septa diverge from the mediastinum to the surface, dividing the testicular parenchyma into 250-300 lobules. Each lobule contains 2-3 convoluted seminiferous tubules length
80-120 cm, formed by spermatogenic epithelium. Heading to the top of the lobule, the convoluted tubules pass into short straight seminiferous tubules, which open into the testicular network, located in the mediastinum of the organ. From the rete testis, 12-15 efferent testicular tubules begin, heading into the epididymis, where they empty into the epididymal duct.
Vas deferens (ductusdefers) - a paired tubular organ having an outer diameter of 3 mm, an inner diameter of about 0.5 mm and a length 50 cm. From the tail of the epididymis it rises up behind the testicle, as part of the spermatic cord it rises to the superficial ring of the inguinal canal, passes along the inguinal canal to its deep ring, emerging from the latter it descends along the side wall of the small pelvis down and posteriorly until it merges with the excretory duct of the seminal vesicle . The terminal section is expanded and forms the ampulla of the vas deferens.
Prostate (prostata) - an unpaired muscular-glandular organ that secretes a secretion that is part of sperm and participates in the exchange of male sex hormones. It is located at the bottom of the pelvis under the bladder, to which the expanded part of the gland is adjacent - the base. The lateral parts of the gland (lobes) are connected by an isthmus through which the urethra passes. On the outside, the gland is covered with a capsule, its substance is formed by smooth muscle tissue and glandular parenchyma, forming prostatic glands, the excretory ducts of which open into the prostatic part of the urethra.
Bulbourethral gland (glandulabulbourethralis) - paired secretory organ of round shape with a diameter of 3-8 mm; produces a viscous fluid that protects the mucous membrane of the male urethra. It is located behind the membranous part of the urethra in the thickness of the deep transverse muscle of the perineum. The duct of the gland opens into the spongy part of the urethra.
Penis (penis- lat.,phallus- Greek)- consists of the posterior part of the root, which is attached to the pubic bones, and the anterior free part - the body, which ends in the head. It is formed by two adjacent cavernous bodies, under which the corpus spongiosum is located. The posterior ends of the cavernous bodies form the peduncles of the penis, attached to the lower branches of the pubic bones, the anterior cylindrical sections are fused with each other and surrounded by a common tunica albuginea. The corpus spongiosum in the posterior section forms an extension (bulb), and in the anterior section - the head of the penis, is surrounded by the tunica albuginea and is penetrated throughout the entire length by the urethra. From the tunica albuginea of the spongy and cavernous bodies, septa extend inward, dividing their cavity into numerous cavities, lined from the inside with endothelium and filled with blood.
The spongy and cavernous bodies are surrounded by common fascia. The body of the penis is covered with thin movable skin, forming a double fold around the head - the foreskin; on the inner surface of the latter, the glands of the foreskin open, producing a sebaceous secretion - lubricant of the foreskin (smegma).
Male urethra (urethramasculina) - has the shape of a tube with a diameter of 0.5-0.7 cm, a length of 16-22 cm. The urethra has prostatic, membranous and spongy parts. In the prostate part, on the posterior wall, there is a ridge with a seminiferous mound, on which the openings of the ejaculatory ducts open. The membranous part is narrowed, passes through the urogenital diaphragm, has a convex bend downward, and is surrounded by circular bundles of skeletal muscles that form the urethral sphincter; the spongy part ends on the glans penis with a relatively narrowed external opening of the urethra.
The female genital organs are divided into internal (ovary, uterus, fallopian tubes, vagina) and external (pubis, labia majora and minora, clitoris, vestibule of the vagina, major and minor glands of the vestibule).
Ovary (ovarium- lat.,oophoron- Greek)- a paired female reproductive gland that produces eggs and female sex hormones; located in the peritoneal cavity of the small pelvis. It has a flattened ovoid shape, outer and inner surfaces, two edges: free and mesenteric, with which the ovary is attached to the posterior leaf of the broad ligament of the uterus and two ends: uterine, from which the own ligament of the ovary extends to the uterus and tubal, adjacent to the infundibulum of the fallopian tube. Along the mesenteric the ovarian gate with the vessels and nerves lying in them is located on the edge.
The surface of the ovary is covered by germinal epithelium and the underlying tunica albuginea. The parenchyma contains the cortex and medulla; Primary and vesicular ovarian follicles are located in the cortex. In the first phase of the menstrual cycle, one of the primary follicles develops into a mature follicle (Graafian vesicle), containing a maturing egg and producing estrogenic hormones. A mature ovarian follicle reaches a diameter of 1 cm, has a connective tissue membrane (theca) of the follicle, in which an outer and an internal membrane are distinguished. Adjacent to the inner shell is a granular layer that forms the oviductal mound, in which the egg lies. The cavity inside a mature follicle contains follicular fluid. Rupture of a mature follicle leads to its transformation into the corpus luteum, which produces progesterone, and the release of the egg into the peritoneal cavity (ovulation); Then the egg enters the funnel of the fallopian tube. If fertilization of the egg does not occur, then the corpus luteum has a diameter of up to 1.0-1.5 cm and functions for 12-14 days (menstrual corpus luteum), after which it is replaced by connective tissue and turns into a whitish body; When pregnancy occurs, the corpus luteum becomes large (1.5 - 2.0 cm) and persists throughout pregnancy (corpus luteum of pregnancy).
Uterus (uterus- lat.;metra, hystera- Greek)- a hollow muscular organ in which the embryo and fetus develop; The uterus is involved in endocrine regulation and the implementation of menstrual function. Located in the pelvic cavity between the bladder and rectum. It has a pear-shaped body, flattened anteriorly - posteriorly with a convex upper part - bottom, at the edges at the border of the fundus and body the fallopian tubes flow into the uterus. Downwards, the body of the uterus through the isthmus continues into the cervix, which with its lower part protrudes into the vagina, respectively, at the cervix the supravaginal and vaginal parts are isolated; the latter has a uterine opening bounded by the anterior and posterior lips.
The uterine cavity is slit-like, has a triangular shape in the frontal section, in the upper lateral corners there are openings of the fallopian tubes, in the lower corner the uterine cavity passes into the cervical canal. The wall consists of three layers: the superficial one is formed by the peritoneum (perimetry), the middle one is the muscular layer (myometrium) and is thick; the inner layer - the mucous membrane (endometrium) is covered with a single-layer columnar epithelium and has numerous glands. In the endometrium, there is a functional layer that is periodically rejected during menstruation and a basal layer, from which endometrial regeneration occurs in the first phase of the cycle. The longitudinal axes of the body and cervix usually form an angle, open anteriorly; in the correct position, the fundus of the uterus faces forward and slightly upward. The uterus is fixed by paired ligaments: round, wide, main (cardinal), sacrouterine, vesicouterine.
Oviduct (tubauterina- lat.,salpinx- Greek)(fallopian tube) - a paired tubular organ that serves to conduct sperm to the egg and actively carry the egg or embryo into the uterine cavity. Located in the pelvic cavity, lying in the upper edge of the broad ligament of the uterus, the peritoneum of which surrounds the tubes on all sides (intraperitoneal). The lumen of the fallopian tube opens medially into the uterine cavity, the part of the tube within the uterine wall is called the uterine tube; leaving the uterus according to its angles, the fallopian tubes are directed to the sides, then backwards. An isthmus extends from the angle of the uterus, then the tube expands, forming an ampulla; the ampulla ends in a funnel, the lumen of which opens into the peritoneal cavity near the tubal end of the ovary. The edge of the funnel forms fimbriae, the longest of which is fixed to the ovary. Upon exiting the ovary, the egg is close to the fimbriae, which direct its movement into the lumen of the funnel and ampulla of the fallopian tube, where fertilization by sperm usually occurs.
The wall of the fallopian tube is covered on the outside with a serous membrane; on the inside there is a muscular layer, consisting of an outer longitudinal and an inner circular layer. Internal - the mucous membrane forms longitudinal folds, has mucous glands, its surface is covered with ciliated epithelium, the movement of the cilia ensures the flow of fluid towards the uterus. /
Vagina (vagina- lat.,colpos- Greek)- a tubular organ located in the pelvic cavity from the cervix to the vestibule of the vagina, where it opens with an opening; The hymen (hymen) is located at the border of the vagina and the vestibule of the vagina. The vagina has anterior and posterior walls; at the top, at the junction with the cervix, they form a vaginal vault around it, the posterior part of which is deeper. The vaginal wall has three membranes: the outer one is adventitial, the middle one is muscular, in which longitudinal bundles predominate, and the inner one is the mucous membrane, directly fused with the muscular one, formed by multilayered squamous non-keratinizing epithelium, which forms numerous transverse vaginal folds.
Female urethra (urethrafeminina) - a short tubular organ that begins with an internal opening from the bladder and ends with an external opening anterior and above the opening of the vagina. It forms an arch, convex posteriorly, at the point of passage through the urogenital diaphragm it is surrounded by circular bundles of skeletal muscle fibers that form a voluntary sphincter.
Includes internal and external genitalia.
Internal male genitalia.
These include: testicles with epididymis, vas deferens and ejaculatory ducts, seminal glands, prostate gland and bulbourethral glands.
Testicle,testis ,or testis,- a paired male gland weighing 20-30 g. The functions of the testicles are the formation of male germ cells - sperm, as well as the release of male sex hormones into the blood, i.e. The testicles are both an external and internal secretion gland. The testicles are located in a special container - moshonke, and the left is lower than the right. They are laid in the abdominal cavity, and by the time of birth they descend into the inguinal canal, carrying the peritoneum with them. Undescended testicle is called monorchism, undescended testicles – cryptorchidism. The testicles are separated from each other by a septum and surrounded by membranes. The length of the testicle is on average 4 cm, width - 3 cm, thickness - 2 cm. The testicle is oval in shape, dense in consistency and somewhat flattened on the sides. It distinguishes two surfaces: more convex external and internal, as well as twothe edges: front and back. In the testicle they secrete upper And lower ends (poles).
The peritoneum forms a closed serous cavity around the testicle. Under serous shell there is another shell of the testicle - albuginea, under which is parenchymatesticles. On the inner surface of the posterior edge of the testicle, the tunica albuginea forms a thickening - mediastinum testicles, from which dense connective tissue extends into the thickness of the organ partitions testicles, dividing the gland into numerous (from 250 to 300) pyramidal slices, with their apexes facing the mediastinum of the testicle, and their bases facing the tunica albuginea. Each lobule contains 2-3 convoluted seminiferous canaltsa, 60-90 mm long, surrounded by loose connective tissue with a large number of blood vessels. The inside walls of the convoluted seminiferous tubules are lined with a special multilayer spermtogenic epithelium, in which the formation of male germ cells occurs - sperm. This process is called stolematogenesis.
Sperm
These are motile cells, about 70 microns long. The speed of their movement along the tubules is about 3.5 mm per minute.
They move towards the egg due to chemotaxis. The lifespan and fertilizing ability of human sperm ranges from several hours to two days.
The sperm has a nucleus, cytoplasm with its organelles and a cell membrane. The spermatozoon has a rounded head and thin long tail. The head contains a nucleus, in front of which there is a structure called acrosome. The acrosome has a set of enzymes that are capable of dissolving the egg membrane during fertilization. If the acrosome is underdeveloped or absent, the sperm is not able to penetrate the egg and fertilize it.
The tail of the sperm contains contractile elements (bundles of fibrils) that ensure the movement of the sperm. When passing through the vas deferens, liquid secretions of the sex glands - the seminal vesicles, prostate and bulbourethral glands - are added to the sperm. As a result, a liquid environment is formed in which the sperm are located - this is sperm.
Spermatogenesis
Spermatozoa are formed in humans throughout the active period of a man’s life. The duration of development and formation of mature sperm from their precursors - spermatogonia is about 70-75 days. This process occurs in the convoluted seminiferous tubules of the testicle. Initially, spermatogonia (the number in one testicle is up to 1 billion), intensively multiply and divide mitotically. At the same time, their number is increasing. Subsequently, some spermatogonia retain the ability to divide, others divide twice more in the form of meiosis. As a result, from each such spermatogonia, which has a diploid (double) set of chromosomes (46), 4 are formed spermatids. Each spermatid has a haploid (single) set of chromosomes (23). Spermatids gradually turn into spermatozoa
The formed sperm enter the lumen of the seminiferous tubules of the testicle and, together with the fluid secreted by the walls of the tubules, gradually move towards the epididymis, which also serves as a reservoir for sperm. The number of sperm produced is enormous. 1 ml of sperm contains up to 100 million sperm.
Between the spermatogenic epithelium of the convoluted seminiferous tubules of the testicles are located supportive cells (Sertoli cells), performing a trophic function for it. In addition, there are special cells - endocrinocytes (Leydig cells), which produce testosterone. Sperm are produced only in the convoluted seminiferous tubules of the testicle. All other testicular tubules and the ducts of the epididymis are the vas deferens. Spermatozoa are part of semen, the liquid part of which is formed from the secretions of the seminal glands and prostate gland.
Arriving from all lobules of the testicle, the convoluted seminiferous tubules merge to form short straight seminiferous tubules, which flow into the rete testis. 12-15 departs from this network testicular efferent tubules, which pierce the tunica albuginea and penetrate the head of the appendage.
epididymis, located along the posterior edge of the testicle. There is an extended upper part - head of the epididymis, passing into the middle part - appendage body, which, in turn, continues into the tapering lower part - tailepididymis. On the head of the epididymis there is sometimes a pedunculated vesicle - appendage appendagetesticles.
In the caudal part of the epididymis, its duct passes, bending, into the vas deferens.
Appendage function: maturation of sperm (2-3 days), before ejaculation.
spermatic cord, It is a small round cord 15-20 cm long, located in the inguinal canal from the upper end of the testicle to the deep inguinal ring. Composition of the spermatic cord included : vas deferens, arteries of the vas deferens and testis, venous plexus, lymphatic vessels and nerves. All these formations are enveloped internal spermatic fascia. Outside of it is levator testis muscle, covered with the fascia of the same name. Outside, the entire spermatic cord surrounds external spermatic fascia.
Seminiferous(vas deferens) duct,- a paired organ 40-50 cm long and about 3 mm in diameter. As part of the spermatic cord it goes up to the inguinal canal. It contains 4 parts:
- scrotal located behind the testicle;
- kanaticohowl, passing as part of the spermatic cord to the superficial inguinal ring;
- inguinal- in the inguinal canal;
- pelvic the part extending from the inguinal ring to the prostate gland.
After passing through the canal, the vas deferens descends into the small pelvis to the bottom of the bladder. Near the prostate gland, its terminal part expands and forms ampoule seedwearing duct. In the lower part, the ampulla gradually narrows and turns into a narrow canal, which merges with the excretory duct of the seminal gland in vas deferens. The latter, having passed through the wall of the prostate gland, opens into the prostatic part of the urethra. The wall of the vas deferens consists of mucous membrane shell with submucosa basis, muscular And adventitia shells.
Seminal (vesicular) glands or seminal vesicles,vesiculae seminales - bag-like tubular formations about 5 cm long, forming many bends and protrusions. The glands are a secretory organ located in the pelvic cavity behind and to the side of the bottom of the bladder, above the prostate gland. In each seminal gland, the upper expanded end is distinguished - base, middle part - body and lower, narrowing end which passes into the excretory duct. The wall of the glands is formed by mucous, muscular and adventitial membranes. The cavity of the seminal glands consists of chambers containing protein secretion. It is a viscous yellowish liquid that protects sperm from acidic vaginal contents and gives them motility. The secret also contains fructose(nutrient) and prostaglanumDina(hormones).
It's no secret that for any man his genitals are of great importance, and in the body as a whole they perform very important and responsible functions. The main one is, of course, procreation. This function plays a colossal role in the life of any person. What is the actual anatomy and structure of the male genital organs?
Basic functions of the genital organs
The male reproductive system performs a number of quite important functions that are of great importance in the smooth functioning of the entire organism. They consist of the following responsible processes:
- the production of male germ cells (so-called sperm);
- ejection of sperm into the vagina during sexual intercourse;
- production of male sex hormones.
Male genital organs are divided into two main types: external and internal. The first includes the scrotum and penis, and the second includes the testicles, their appendages, the urethra, the vas deferens, the prostate and other organs associated with it.
Features of the structure of the penis
The male genital organs are characterized by the presence of the main thing - a penis. It is the main source of secretion of a special fluid (sperm) into the woman’s genitals.
The shape and size of the penis can change depending on the degree of filling of the cavernous bodies with blood, or on the level of erection, this is the same thing. The male reproductive system, namely the penis, is formed with the help of three parallel cylindrical bodies, one of them is spongy, and the other two are cavernous. All of them are covered with a dense shell.
The first body, which is located on the underside of the penis, surrounds the urethra (urethra). This is where sperm and urine come out.
The cavernous bodies (right and left cylinders) fill with blood during sexual arousal, and this is what leads to an erection of the penis. They are located in close proximity to the corpus spongiosum. In the middle of these cylinders are the legs of the penis, firmly fixed to the bones of the pelvis.
The genital organs are designed in such a way that at the end of the penis there is a head, which is covered with skin called the “foreskin”. And the openings of the urethra, which are slit-like, are located at the very top of the head.
What is sperm?
Sperm is a special characteristic mixture consisting of spermatozoa and the characteristic secretions of the male glands secreted by the epididymis, prostate gland and seminal vesicles, all of which have their own specific functions in the process of ensuring the movement of spermatozoa directly to an already mature egg.
When ejaculation occurs, an average of about five milliliters of semen is released, containing approximately three hundred million sperm.
An erection is considered a state during which maximum tension of the penis is observed, which facilitates subsequent sexual intercourse. In this process, the corpus spongiosum is filled quite densely with blood, and the characteristic sensations of a straight cord arise.
Male genital organs and their circulatory system
The penis is constantly actively supplied with blood thanks to numerous vessels and nerve fibers that abundantly penetrate it and increase sensitivity during sexual intercourse. The largest number of nerve endings is located in the head of the penis, namely at its crown, where the border of the head and the body of the penis itself passes.
On the lower part of the head there is the most sensitive area, which is called the frenulum of the penis. Here, when inflammation occurs, quite sharp and painful sensations appear, usually aggravated by sexual intercourse. Additionally, in some situations, the foreskin may stick to the glans. This condition appears due to increased accumulation of a special substance. It is usually curdled in appearance and oily to the touch. It's called smegma. It consists of the remains of sweat, dirt and dead skin cells (epidermis).
Testicles and their features
The male reproductive system is characterized by the presence of testicles. They are paired oval organs, similar in size and shape to slightly flattened walnuts. The testicles are located in the scrotum (a sac-like musculocutaneous formation). The approximate weight of one testicle is twenty grams, and the size in adult men is from three to four centimeters.
These organs are quite sensitive to the use of any physical influence. This is primarily due to the fact that the testicles are covered on top with very densely located nerve endings and blood vessels. In addition, they are the organs that are responsible for the production of male reproductive cells (sperm).
Location and significance of the testicles
The organs of the male reproductive system mainly function to enable the process of sperm production to occur. It occurs in the main structure of the testicles, namely the seminiferous tubules, and is called spermatogenesis. As a rule, one testicle in all cases is located lower than the other. There is also a version that for men who are right-handed, the lower testicle is the left one, and for those who consider themselves left-handed, the right one.
In addition, the testicles are also endocrine glands that produce male sex hormones - androgens, the main of which is testosterone. They are smooth on the outside, but in the middle they are divided into two or three hundred lobules, in which the seminal canals are located. These tubules are small tubes that form a spiral. It is here that millions of sperm appear over a period of seventy-two days.
Thus, the testicles perform two very important functions. This is the formation of sperm and the production of male sex hormones.
Functions and significance of the scrotum
The male reproductive system also consists of the scrotum. This organ is a leather pouch located at the very base of the penis. It is covered with delicate skin and has very sparse hairs. The scrotum is divided into a pair of parts according to the number of testicles by a special septum. Depending on the temperature present, the scrotum may increase or decrease in size. This property completely ensures that a constant level of temperature is maintained in the testicles, and this, in turn, is a very important condition in the process of spermatogenesis.
Inside the scrotum there is a very important complex of organs that provides male sexual functions, as well as the ability to procreate. This includes the testicles, their epididymis and the vas deferens. In the walls of the scrotum there is a thin layer of smooth tissue, which contracts during sexual intercourse, during physical education and various sports, and also under the influence of cold. This is a protective reaction that is aimed at preserving the testicles and maintaining their constant temperature, and, in addition, it serves as the key to optimal maturation of sperm.
Features of the vas deferens
The male genital system includes the vas deferens. They are presented in the form of paired canals connecting the urethra with the epididymis. The size of each such duct is about fifty centimeters, and the diameter inside is equal to half a millimeter.
The vas deferens go through a rather complex path, during which they move from the testicles to the abdominal cavity, then overcome the prostate gland, and then go straight to the urethra.
Meaning of prostate
The structure of the male reproductive system also includes an important glandular and muscular organ. This is the prostate gland. It is an unpaired organ that adjoins directly to the bladder below and encircles the urethra.
In size it is no larger than an ordinary chestnut. The urethra passes through the prostate gland. It is the prostate that produces a special secretion that ensures the vital activity of sperm in the seminal fluid. In other words, semen is a secretion of the prostate and seminal vesicles and contains spermatozoa.
The so-called seminal vesicles are not at all a place for storing semen. Just like the prostate, they are actively involved in the process of producing seminal fluid. The secretion of the seminal vesicles helps to liquefy the sperm and promote sperm.
On the left and right sides under the prostate gland, symmetrically in relation to each other, the so-called Cooper glands are located. They have a characteristic pea shape. In addition, they communicate via a special duct directly with the urethra. During the period of sexual arousal, these glands secrete an appropriate secretion, which allows them to moisturize the mucous membrane of the urethra right before the process of ejaculation.
The urethra and its features
The anatomy of the male reproductive system is also based on such an important organ as the urethra. It relates to both the urinary and reproductive systems at the same time, as it serves as the main assistant for the natural excretion of urine and ejection of sperm. The urethra begins at the bladder, and its end is presented in the form of a slit on the head of the penis.
The urethra itself, at the level of the prostate gland, includes the ends of the vas deferens, through which sperm moves. The development of the male reproductive system shows that at the moment of ejection, sperm is ejected through the urethra directly into the woman’s genital tract.
The meaning of seminal vesicles
The seminal vesicles are special paired male sex glands that have the appearance of elongated sacs with a cellular structure. They are located above the prostate gland, namely between the rectum and the lower side of the bladder. In terms of their significance, they serve as a specific repository for a man’s genetic material (sperm).
The functions of the male reproductive system are characterized by the fact that in the seminal vesicles during the process of ejaculation, from three to six milliliters of sperm are released, of which about seventy percent is the secretion of the prostate gland.
According to its direct functions, male seminal fluid is needed not only to neutralize the acidic environment present in the urethra and female vagina, but also to supply sugar. It is this that serves as the source of energy for the process of sperm movement. In addition, prostaglandin hormones are supplied here, which increase the level of contraction of the uterus and its tubes, while accelerating the movement of millions of sperm directly to the egg.
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