View Full Version : Prostate anatomy (Bài của Mỹ Duyên)

01-12-09, 10:04 PM
1.The neurovascular bundles lie postero-laterally, and contain the branch artery, vein, and nerve.
- They provide the main supply and drainage system of the prostate, and assume major importance in prostate surgery, especially regarding maintenance of potency.
- The gland has rich arterial supply deriving from branches of the iliac arteries. The prostate artery, a branch of the internal iliac , divides into capsular and urethral arteries. The former supply two-thirds of the gland and the latter the remainder. They are :the inferior vesical artery and middle rectal artery.
-The prostatic veins form a well-marked prostatic plexus which lies partly in the fascial sheath of the prostate and partly between the sheath and the prostatic capsule. It communicates with the pudendal and vesical plexuses
- The function of the prostate is to store and secrete a slightly alkaline (pH 7.29) fluid, milky or white in appearance, that usually constitutes 25-30% of the volume of the semen along with spermatozoa and seminal vesicle fluid.

- The alkalinity of semen helps neutralize the acidity of the vaginal tract, prolonging the lifespan of sperm. The alkalinization of semen is primarily accomplished through secretion from the seminal vesicles.
- The prostatic fluid is expelled in the first ejaculate fractions together with most of the spermatozoa. In comparison with the few spermatozoa expelled together with mainly seminal vesicular fluid those expelled in prostatic fluid have better motility, longer survival and better protection of the genetic material (DNA).
- The prostate also contains some smooth muscles that help expel semen during ejaculation.
3. Secretions
Prostatic secretions vary among species. They are generally composed of simple sugars and are often slightly alkaline.
In human prostatic secretions, the protein content is less than 1% and includes proteolytic enzymes, prostatic acid phosphatase, and prostate-specific antigen. The secretions also contain zinc with a concentration 500-1,000 times the concentration in blood.
4. Regulation
- To work properly, the prostate needs male hormones (androgens), which are responsible for male sex characteristics.
- The main male hormone is testosterone, which is produced mainly by the testicles. Some male hormones are produced in small amounts by the adrenal glands. However, it is dihydrotestosterone that regulates the prostate.