The prostate is an accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation. It is found in all male mammals. Anatomically, the prostate is found below the bladder , with the urethra passing through it. It is described in gross anatomy as consisting of lobes and in microanatomy by zone. It is surrounded by an elastic, fibromuscular capsule and contains glandular tissue, as well as connective tissue.
The prostate produces and contains fluid that forms part of semen , the substance emitted during ejaculation as part of the male sexual response. This prostatic fluid is slightly alkaline , milky or white in appearance. The alkalinity of semen helps neutralize the acidity of the vaginal tract , prolonging the lifespan of sperm. The prostatic fluid is expelled in the first part of ejaculate, together with most of the sperm, because of the action of smooth muscle tissue within the prostate.
In comparison with the few spermatozoa expelled together with mainly seminal vesicular fluid, those in prostatic fluid have better motility , longer survival, and better protection of genetic material. Disorders of the prostate include enlargement , inflammation , infection , and cancer. The prostate is a exocrine gland of the male reproductive system. In adults, it is about the size of a walnut , [ 2 ] and has an average weight of about 11 grams 0.
It sits below the urinary bladder and surrounds the urethra. The part of the urethra passing through it is called the prostatic urethra , which joins with the two ejaculatory ducts. The internal structure of the prostate has been described using both lobes and zones. The prostate has been described as consisting of three or four zones. The "lobe" classification describes lobes that, while originally defined in the fetus, are also visible in gross anatomy, including dissection and when viewed endoscopically.
Inside of the prostate, adjacent and parallel to the prostatic urethra, there are two longitudinal muscle systems. On the front side ventrally runs the urethral dilator musculus dilatator urethrae , on the backside dorsally runs the muscle switching the urethra into the ejaculatory state musculus ejaculatorius. The prostate receives blood through the inferior vesical artery , internal pudendal artery , and middle rectal arteries. These vessels enter the prostate on its outer posterior surface where it meets the bladder, and travel forward to the apex of the prostate.
