THERE IS AN important group of biological structure working in close cooperation with the nervous system in adjustive behaviour.THIS IS THE system of the ductless and ENDOCRINE,GLANDS.THESE GLANDS ARE WELL SUPPLIED with blood vessels but have no ducts through which to channel the substance they produse,instead they pass their secretion directly into the blood stream.THE CHEMICAL substance secreted by the ENDOCRINE GLAND,are called HORMONES;THEY GREATLY affect the function of the body and the course of its development.

THE ACTIVITY OF ENDOCRINE GLAND is regulatery in nature.THERE SECRETION serves to control the individual,s metabolism,the chemical recation taking place in all living tissue by which energy is provided to carry on the life processes and by which growth take place in bones,muscles and nervous tissue.THESE GLANDS ALSO HELP to maintain internal conditions within an optimal range.THEY PLAY A LARGE ROLE in co-ordinating the activities of the body.IN SUDDEN fears for example,a hormons is circulated through the blood which brings about such widely diverse activities as dialation of the pupil of the eye,constrication of the blood vessels in the wall of the stomach ,and an increase in the rapidity with which blood clots in the presence of the air.


IN HELPING TO MAINTAIN equilbirium and coordinate body functions,the various endocrine gland closely work together.IF ONE gland is working slowly,another gland may relases the hormones to stimulaion;if one gland is over active,another may secrate the hormones that maybe slow it down.DAMAGE OR REMOVEL of one gland may disrupt the functioning of the entire system.


1 THE PITUITARY GLAND

THE PITUATIRY, A small structure attached to the underside of the brain and located in the centre of the head,secrets a numbers of hormones,which perform various functions concerned with growth and maintaince.PARTICULERLY, vital to normal bodly development during childhood is the pituatry growth hormones,control the growth of the skeleton muscles and various internal organs.THE PITUATRY ALSO produse the variety of middle man hormones,which act directly upon other endocrine glands, most notably the thyriod glands, the sex gland and the adernal cortex to stimulate there functioning.


2 THE THYRIOD GLAND

LOCATED IN THE NECK at either side of the ADAM APPLE are the thyriod glands.which produse the harmone called thyroxin. OPERATING IN close connection with pituatry it affects the body metabolism and help to control the rate of physcial growth.HIGH THYRIOD OUTPUT goes with the high general activity and low output goes with the sluggishness of movement.LIKE THE PITUATRY,the thyriod appeared to secreate hormones which stimulate the sex glands.THYRIOD SECRETION influence the structure of the nervous system,especially in the devlopment of intelligent system.


3 THE ADERNAL GLANDSLOCATED AT THE upper side of the kidneys are the two adernal glands,each consisting of the two parts: an inner core and an outer layer.THE ADERNAL MEDULLA is directly control by the nervous system,which stimulate the gland to secrets its hormones.


4 THE GONADS
THE SEX GLANDS or gonads, have a dual purpose in both sexs:
THE SECRETION of sex hormones that influence bodily development and behaviour,
THE production of gamets.

REFERANCE

PSYCHOLOGY AND LIFE BY FLOYD L,RUCH

REGARDS