________________
120
Preksha Dhyana :
The function of the testes is controlled by the hypothalamic-pituitary system. The follicle-stimulating hormone (FSH) stimulates growth of seminiferous tubules.
Two of the important function of the testes are : (1) Spermatogenesis is the process by which primitive male gametes (spermatogonia) become mature sperm. At puberty, spermatogonia begin to divide under the influence of FSH, and will continue to do so throughout life with a decrease in the later years.
The gametes undergo mitotic division to form primary spermatocytes, each containing 44 somatic and 2 sex chromosomes. By a meiotic division it produces a pair of secondary spermatocytes, each containing 22 somatic and one sex chromosome. The sex-chromosomes are called X and Y. They can be distinguished from the others, which are somatic (body) chromosomes. An ovum has two X chromosomes (XX), whereas a sperm has X and X chromosome (XY). The fertilized cell will have either an 'X' or a ‘Y' chromosome, but not both, from the sperm. The sex of a child clearly depends on whether it inherits an X or a Y chromosome from its father. (2) Secretion of Testosterone. Very little testosterone (the principal male hormone) is secreted in childhood. At puberty, hormone from the anterior pituitary stimulates its production. Its secretion promotes maturation of the reproductive organs and causes the appearance of secondary sexual characteristics (hair over the chest, pubis and on the faces. Its secretion is essential for development of the spermatozoa beyond the primary stage. Functions of the System
The male system is concerned with spermatogenesis and the introduction of spermatozoa into the female system during sexual intercourse. Erection of the male organ, emission of spermatozoa and other constituents of semen into the urethra and ejaculation of the semen out of the urethra are performed by the male system.
THE FEMALE REPRODUCTIVE SYSTEM The Ovaries and their Functions
The Ovaries are the female gonads or sex glands.
Jain Education International
For Private & Personal Use Only
www.jainelibrary.org
