Prostate Gland Lecture Notes PDF

Prof. Dr. Naseer J. H. Almukhtar College of Med. / UOB Lecture : II Prostate gland: The prostate develops from epithelial buds of the urethra after the ejaculatory ducts have entered the urethra, which develop into a five- lobed adult gland. The prostate gland se...

Prof. Dr. Naseer J. H. Almukhtar College of Med. / UOB Lecture : II Prostate gland: The prostate develops from epithelial buds of the urethra after the ejaculatory ducts have entered the urethra, which develop into a five- lobed adult gland. The prostate gland secrets a thin, milky fluid that contain citrate ion, calcium, phosphate ion, a clotting enzyme and a profibrinolysin. During emission, the capsule of the prostate gland contracts simultaneously with contractions of the vas deferens, so that the thin, milky fluid of the prostate gland adds further to the bulk of the semen. A slightly alkaline characteristic of the prostatic fluid may be quite important for successful fertilization of the ovum, because the fluid of the vas deferens is relatively acidic owing to the presence of citric acid and metabolic end products of the sperm and, consequently, helps to inhibit sperm fertility. Also, the vaginal secretions of the female are acidic (pH of 3.5 to 4.0) sperm do not become optimally motile until the pH of the surrounding fluids rises to about 6.0 to 6.5. Consequently, it is probable that prostatic fluid helps to neutralize the acidity of these other fluids after ejaculation and thus enhances the motility and fertility of the sperm. Prostate gland also secretes spermine which is responsible for the odour of the semen, additional to the alkaline effects. Prostaglandins also produced from the prostate gland, which stimulate peristaltic contractions of the female reproductive tract that help for spread the semen through the uterus, and reducing the mucus viscosity of cervical female canal, to help sperm for penetration of this area. The prostatic secretions account for 0.5 ml. Proteinase enzyme secreted by the prostate gland is responsible for semen liquefaction. 1 Prof. Dr. Naseer J. H. Almukhtar College of Med. / UOB 2 Prof. Dr. Naseer J. H. Almukhtar College of Med. / UOB Bulbourethral gland (Cowper’s gland): Pea-sized gland joined to the urethra after the seminal vesicle and the prostate gland. Cowper’s gland secrete mucus secretion by compression between the external sphincter of the bladder and contraction of the perineal muscles. Cowper’s glands secretion account for 0.1 to 0.2 ml, which help for lubrication of the urethral duct and help for lubrication during intercourse, and neutralize the contents of normally acidic urethra, as well as, to reduce the acidity of the vagina. This secretions are concomitant with mucus secretion from the gland of Littre (Periurethral gland) which distributed along the 18 cm of the lining epithelial layer of the urethra. Erection of penis: Erection is the first effect of male sexual stimulation, and the degree of erection is proportional to the degree of stimulation, whether psychic or physical. Erection occurs by dilation of the arterioles of the penis, the meshwork of blood sinuses fills with blood. Venous outflow is thus compressed and the penis firm (hard) and erect. Arteriolar dilatation is produced by parasympathetic nerves releasing acetylcholine and VIP and nonadrenergic-noncholinergic nerves releasing the powerful vasodilator nitric oxide (EDRF). 2-4 ml of seminal fluid containing several hundred million spermatozoa are deposited in the female vagina during a normal of complete penis erection and ejaculation process. 3