STD-12 UNIT-6 CHA-3
HUMAN REPRODUCTION
MALE REPRODUCTIVE SYSTEM FUNCTION, HORMONAL CONTROL,DISORDERS
Functions of Male Reproductive System
- Spermatogenesis. The germinal epithelial cells of seminiferous tubules produce sperms .
- Male Sex hormones . Leydig's cells ( interstitial cells ) produce male sex hormones ( e.g. , testosterone )
- Transfer of Sperms . Copulatory organ ( e.g. penis ) transfers sperms into the vagina of the female during copulation
Semen
- Semen is a collection of secretions from the seminal vesicles , prostate gland and Cowper's glands and sperms from testes .
- Semen is ejected from the penis during ejaculation.
- A single ejaculation may contain 200 to 300 million spermatozoa (sperms) of which atleast 60 % sperms must have normal shape and size and atleast 40 % of them must show vigorous motility for normal fertility .
- Semen has a pH of 7.35 to 7.50 ; its alkalinity helps to neutralize the acidity of the urethra left from the passage of urine and protects the sperms from the acidity of the vagina .
- Infact Nuid part of semen is called seminal plasma .
Hormonal Control of Male Reproductive System
- The growth , maintenance and functions of the male reproductive organs are under the hormonal control as described below .
- GnRH is secreted by the hypothalamus .
- It stimulates the anterior lobe of the pituitary gland to secrete LH and FSH.
- In male LH is called interstitial cells stimulating hormone ( ICSH ) because it stimulates interstitial cells ( Leydig's cells ) of the testes to secrete androgens .
- Testosterone is the principal androgen .
- FSH stimulates Sertoli cells of the testes to secrete an androgen - binding protein ( ABP ) that concentrates testosterone in the seminiferous tubules.
- Sertoli cells also secrete a protein hormone called inhibin which suppresses FSH synthesis .
- FSH acts directly on spermatogonia to stimulate sperm production .
Onset of Puberty in Human Male
- Puberty is a period when reproduce tive organs start functioning .
- Puberty in human male is attained between 13-16 years .
- Hormone testosterone plays a significant role in the onset of puberty .
- Gonadotropin releasing hormone ( GnRH ) is secreted by the hypothalamus , which stimulates the anterior lobe of the pituitary gland to secrete luteinising hormone ( LH ) and follicle stimulating hormone (FSH ) .
- In males LH may be called interstitial cells stimulating hormone ( ICSH ) because it stimulates the interstitial cells ( Leydig's cells ) of the seminiferous tubules of the testes to secrete androgens. Testosterone is principal androgen which brings about the growth of the puberty in human males .
- secondary sex organs and development of secondary sexual characters . This is onset of puberty in human males.
Disorders of Male Reproductive System
- Benign Prostatic Hypertrophy ( BPH ) . This is the enlargement of the prostate gland . li often occurs in old age . It compresses the urethra , causing frequent night urination ( nocturia ) or difficult or painful micturition . Untreated BPH may lead to kidney damage .
- Prostate cancer . Cancer of the prostate gland is an extremely common malignancy . accounting for 2 to 3 % of male deaths . Malignant prostate cells are usually stimulated by testosterone , so treatment often involves removal of the testes , thereby preventing production of the hormone . The most commonly used marker enzyme in clinical diagnosis of prostate cancer is acid phosphatase .
- Impotence . Impotence is the inability to achieve or hold an erection of penis long enough to complete sexual intercourse . Psychological factors are most often cited as causes . but neurological disorders , vascular disorders , and syphilis can also cause impotence . Certain drugs ( e.g. , Viagra ) are available to cure impotency .
- Sterility . In males sterility is the inability of a sperm to fertilize an ovum .
- Inguinal hernia . Tearing of inguinal tissue may result in the protrusion of a part of intestine into the scrotum . This condition is called inguinal hernia .
- ADAM ( Androgen Deficiency in Ageing Males ) . It is also called andropause ( male menopause ) . It is due to reduced production of testosterone . Unlike female menopause there is no specific age for males
- Cryptorchidism ( Crypto - hidden , Orchid - testis ) . It is a condition in which the testes do not descend into the scrotum . It is caused by deficient secretion of testosterone by fetal testes . Retention of testes in the abdominal cavity results in sterility .
- Hydrocoele . It is a collection of fluid , usually in the tunica vaginalis of the testis .
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