Bladder Seminal VesiclesProstate Gland Vas DeferensEpididymis Glans Penis
Corpus Cavernosum Urethral Opening ScrotumLabium MajoraLabium Minora UrethraClitoris Pubic bone Vagina Urinary Bladder
Cervix Uterus OvaryFallopian TubeUreter Rectum Axoneme Basal BodyNucleus Acrosome Sperm Testicle Endpiece Corona RadiataZona Pellucida Egg CytoplasmFirst Polar BodyOvum Mitochondria
Male Reproductive System consists of Internal and External Reproductive Organs or Genitilia.
1. External Reproductive Organs : They are the genitilia external to the Body cavity and visible to the naked eye. These are Penis and Scrotum.
a. Penis : Male Penis is a copulatory organ (organ involved mainly in performing sexual activity). It has a long shaft and a swollen round terminal portion called Glans Penis. There is a Foreskin covering the Glans Penis and adjacent part of the Shaft. People of different cultures usually Circumcise the Foreskin in their Children. Penis is made up of two Corpora Cavernosa dorsally side by side and one Bulbous Spongiosum on ventral side in centre. These all are expandable tissues with Sinuses which can be filled with blood when required to produce overall expansion of the Penis. Urethra is present inside the Penis is a tube which carries Sperms as well as Urine out of the Body.
b. Scrotum : Scrotum is a pouch like organ made up of skin which hangs down from the Body below Penis on inferior side of the Pelvis. It contains Dartos Muscle which is involved in bringing up and down the Scrotum Skin and thus Testes within.
Scrotum contains a pair of Testes. Scrotum protects and nourishes Testes. It also provides suitable temperature for its function by the help of Dartos Muscle. Testes are a pair of oval structure present within the Scrotum. They are related with the Sperm production which is male reproductive cell (Gamete). Each testes is covered up by three membranous layers and is convoluted from inside.
2. Internal Reproductive Organs : These Reproductive Organs reside within the Body. They are as follows :
a. Epididymis : Epididymis is a mass of white, convoluted and tightly coiled tubes. It is present on the dorsal side of both Testes. It contains sperms formed inside the Testes and matures them before passing onto the Vas Deferens.
b. Vas Deferens : It is a long tube carrying Sperms from Epididymis to the Pelvic Cavity. It is usually 30 cm long. It is also known as Sperm Duct.
c. Accessory Glands : There are many glands along the Duct System that provide different secretions to the Sperms forming a fluid secretion ultimately called Semen. They are as follows:
Seminal Vesicles are present on both sides of the Vas Deferens near Urinary Bladder. They provide fructose in their secretion and constitute 70 % of the Semen. Their secretion is sticky and yellowish in colour.
Prostate Gland is present just below the Urinary Bladder and surrounds the Urethra and terminal parts of the Sperm Ducts. It produces Milky secretions which make Semen less sticky.
Bulbourethral Glands are paired glands just below the Prostate Glands. They are almost the shape and size of a pea. They neutralize the acidity of the Semen.
PHYSIOLOGY AND FUNCTION :
- Sperm Production : Sperm is the Male Gamete involved in reproduction. The process of Sperm formation is called Spermatogenesis. It occurs inside testes by division of the Primary Spermatozoa. It is a Haploid form of division called Meiosis. Sperms formed are having Half the number of Chromosomes as normal cells. They are stored inside Testes and transferred via Epididymis and Sperm Duct to the Urethra and expelled out during Ejaculation.
- Sexual Intercourse (Copulation) : When a male is aroused his Penis is filled with blood resulting in its expansion and hardening. It becomes erect and considerably increased in size. Penis is then inserted into the Vagina (female copulatory organ) and walls of the Vagina massage it. It results in the production of the Semen and brain signals result in Orgasm as response of the body.
- Orgasm and Ejaculation : When sexual activity is continued it terminates in form of a highly pleasing sensation arising as a result of brain impulses. This state is called Orgasm. During this state muscles of the Body contract and relax and Semen is expelled out of the Urethra. This expulsion of the Semen is called Ejaculation. Ejaculate of a normal person contains over 15 million Sperms per milliliter.
- Fertilization : Sperms present inside the Semen are motile. They travel upwards in the Vagina of the female and reach the Egg (female gamete). One of the sperms penetrates the Egg and this process is called Fertilization. It results in the formation of Zygote with normal number of Chromosomes (one half from sperm one from egg). It divides further and forms Embryo, and later Fetus. Fetus develops into a newborn Baby.
CLINICAL SIGNIFICANCE :
- Male Reproductive System is of special interest for clinicians as many pathological problems arise in it and result in Infertility (inability to procreate) or Impotence (inability to carry out sexual activity).
- Male Reproductive System is often involved in spread of certain diseases by pathogens like Hepatitis, AIDS, Syphilis etc.
- Male Reproductive System can also get infected by pathogens like Bacteria (syphilis, gonorrhea) and Fungi (candida) etc.