THE MALE REPRODUCTIVE SYSTEM
Picture: Male reproductive organs.
Source: William F.Ganong. ibid, p 318
The testes are made up a series of convoluted seminiferous tubules along the wall of which the spermatozoa are formed from the primitive germ cells [spermatogenesis]. The tubules drain into a network of ducts in epididymis. From there , spermatozoa pass into the vas deferens. They enter through the ejaculatory ducts into the urethra in the body of the prostate at the time of ejaculation. Between the tubules in the testes are nests of cells containing lipid granules, the interstitial cells of Leydig, which secrete testosterone into the blood stream.
Effect of temperature:
Spermatogenesis requires a temperature considerably lower than that of the interior of the body .When testes are in the scrotum, they are kept cool enough for spermatogenesis to proceed normally. When they are retained in the abdomen or when, in experimental animals, they are held close to the body by tight cloth binders, degeneration of the tubular walls and sterility result.
Spermatozoa are first produced at puberty and spermatogenesis activity is maintained into old age, so that there is no definite end to reproductive life in the male.
Semen
The fluid that is ejaculated at the time of orgasm, the semen, contains sperms and the secretions of the seminal vesicles, prostate, Cowper’s glands, and the urethral glands. The volume per ejaculate is 2-5 ml after 3 days of continence. There are normally about 80-120 million sperms / ml of semen, even though it takes only one sperm to fertilize the ovum. Human sperms move at the speed of 3 mm/ min through the female genital tract.
Composition of human semen:
Color: White opalescent.. Specific gravity:1.028.pH: 7.3-7.5.
Sperm count: Average about 100 million/ ml, .with fewer than 20 % abnormal forms.
Other components: Fructose, ascorbic acid from seminal vesicle [60 % of total volume]. Citric acid , cholesterol, phospholipids, fibrinolysin, fibrinogenase and prostaglandins from prostate [20 % of total volume]. Phosphate and bicarbonate as buffers.
Fructose is an important constituent of the medium in which spermatozoa are stored in vitro for use in artificial insemination.
3. THE FEMALE REPRODUCTIVE SYSTEM.
Effect of temperature:
Spermatogenesis requires a temperature considerably lower than that of the interior of the body .When testes are in the scrotum, they are kept cool enough for spermatogenesis to proceed normally. When they are retained in the abdomen or when, in experimental animals, they are held close to the body by tight cloth binders, degeneration of the tubular walls and sterility result.
Spermatozoa are first produced at puberty and spermatogenesis activity is maintained into old age, so that there is no definite end to reproductive life in the male.
Semen
The fluid that is ejaculated at the time of orgasm, the semen, contains sperms and the secretions of the seminal vesicles, prostate, Cowper’s glands, and the urethral glands. The volume per ejaculate is 2-5 ml after 3 days of continence. There are normally about 80-120 million sperms / ml of semen, even though it takes only one sperm to fertilize the ovum. Human sperms move at the speed of 3 mm/ min through the female genital tract.
Composition of human semen:
Color: White opalescent.. Specific gravity:1.028.pH: 7.3-7.5.
Sperm count: Average about 100 million/ ml, .with fewer than 20 % abnormal forms.
Other components: Fructose, ascorbic acid from seminal vesicle [60 % of total volume]. Citric acid , cholesterol, phospholipids, fibrinolysin, fibrinogenase and prostaglandins from prostate [20 % of total volume]. Phosphate and bicarbonate as buffers.
Fructose is an important constituent of the medium in which spermatozoa are stored in vitro for use in artificial insemination.
3. THE FEMALE REPRODUCTIVE SYSTEM.
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