The human male reproductive system consists of a number of sex organs that are a part of the human reproductive process. In the case of men, these sex organs are located outside a man’s's body, around the pelvic region.
The main male sex organs are the PENIS and the tESTIS which produce semen and sperm, which as part of sexual intercourse fertilize an ovum in a woman's body and the fertilized ovum (zygote) gradually develops into a fetus, which is later born as a child.
PENIS
The penis (plural penises, penes) is an external sexual organ of certain biologically male organisms, in both vertebrates and invertebrates.
The penis is a reproductive organ, technically an intromittent organ, and for placental mammals, additionally serves as the external organ of urination. The penis is generally found on mammals and reptiles.
The penis has a long shaft and enlarged tip called the glans penis. The penis is the male copulatory organ. When the male becomes sexually aroused, the penis becomes erect and ready for sexual intercourse. Erection is achieved because blood sinuses within the erectile tissue of the penis become filled with blood. The arteries of the penis are dilated while the veins are passively compressed so that blood flows into the erectile cartilage under pressure. The male penis is made of two different tissues,and soft spongey tissue. Cartlidge is not in the penis.
Corpus Cavernosum
The corpus cavernosum penis is one of a pair of sponge-like regions of erectile tissuewhich contain most of the blood in the male penis during erection. This is homologousto the corpus cavernosum clitoridis in the female. The term literally means "cave-like body" (plural: corpora cavernosa).
The two corpus cavernosa and corpus spongiosum (also known as the corpus cavernosum urethrae in older texts and in the diagram to the right) are three expandable erectile tissues along the length of the penis which fill with blood during erection. The two corpora cavernosa lie along the penis shaft, from the pubic bones to the head of the penis, where they join. These formations are made of a sponge-like tissue containing irregular blood-filled spaces lined by endothelium and separated by connective tissuesepta. The corpus spongiosum is one smaller region along the bottom of the penis, which contains the urethra and forms the glans penis.
In some circumstances, release of nitric oxide precedes relaxation of muscles in the corpora cavernosa and corpus spongiosum. The spongy tissue fills with blood, from arteries down the length of the penis. A little blood enters the corpus spongiosum; the remainder engorges the corpora cavernosa, which expand to hold 90% of the blood involved in an erection, increasing both in length and in diameter. The function of the corpus spongiosum is to prevent compression of the urethra during erection.
Blood can leave the erectile tissue only through a drainage system of veins around the outside wall of the corpus cavernosum. The expanding spongy tissue presses against a surrounding dense tissue (tunica albuginea) constricting these veins, preventing blood from leaving. The penis becomes rigid as a result. The glans penis, the expanded cap of the corpus spongiosum, remains more malleable during erection because its tunica albuginea is much thinner than elsewhere in the penis.
TESTICLES
The testicle (from Latin testiculus, diminutive of testis, meaning "witness" [of virility], plural testes) is the male generative gland in human. The testes hang outside the abdominal cavity of the male within the scrotum. They begin their development in the abdominal cavity but descend into the scrotal sacs during the last 2 months of fetal development. This is required for the production of sperm because internal body temperatures are too high to produce viable sperm.
Function
Like the ovaries (to which they are homologous), testes are components of both the reproductive system (being gonads) and theendocrine system (being endocrine glands). The respective functions of the testes are:
- producing sperm (spermatozoa)
- producing male sex hormones of which testosterone is the best-known
- Both functions of the testicle, sperm-forming and endocrine, are under control of gonadotropic hormones produced by the anteriorpituitary:
- luteinizing hormone (LH)
- follicle-stimulating hormone (FSH)
EPIDIDYMAE
The epididymis (pronounced /ɛpɨˈdɪdɨmɪs/, plural: epididymides /ɛpɨˌdɪdɨˈmiːdiːz/) is part of the male reproductive system and is present in all male mammals. It is a narrow, tightly-coiled tube connecting the efferent ducts from the rear of each testicle to its vas deferens.
The epididymus is a whitish mass of tightly coiled tubes cupped against the testicles. It acts as a storage place for sperm before they enter the vasa deferentia, tubes that carry sperm form the testes to the urethra.
Role in storage of sperm and exhaggeration
Spermatozoa formed in the testis enter the caput epididymis, progress to the corpus, and finally reach the cauda region, where they are stored. Sperm entering the caput epididymis are incomplete - they lack the ability to swim forward (motility) and to fertilize an egg. During their transit in the epididymis, sperm undergo maturation processes necessary for them to acquire these functions.[1] Final maturation is completed in the female reproductive tract (capacitation).
During ejaculation, sperm flow from the lower portion of the epididymis (which functions as a storage reservoir). They have not been activated by products from the prostate gland, and they are unable to swim, but are transported via the peristaltic action of muscle layers within the vas deferens, and are mixed with the diluting fluids of the seminal vesicles and other accessory glands prior to ejaculation (forming semen).
The epididymis possesses numerous, long atypical microvilli. These processes are often called stereocillia; this is incorrect, as they neither contain the microtubular structures of cilia nor function like cilia.
1: Epididymis
2: Head of epididymis
3: Lobules of epididymis
4: Body of epididymis
5: Tail of epididymis
6: Duct of epididymis
7: Deferent duct (ductus deferens or vas deferens)
reviewed by Bambang Widjanarko
Last Juni 2009
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