Describe The Hormones and Type
DESCRIBE THE HORMONES AND TYPES :- Hello friends welcome to yourstudynotes.com today topic is hormones. I hope this topic is very useful in your study. so let’s start.
The secretion of endocrine gland is commonly called as hormone. This name has been derived from the greek word “hormonein”which literally means to excite. English physiologist E.H. Starting coined the term hormone. According to Guillemin (1977)hormones are chemical messengers which after begin secreted by certain cells reach to the distance or nearby target cell through blood or lymph or the axons of the neurons and affect their physiology
Type of hormones:-
Hormones are grouped into two main categories:-
These hormones are circulated to all the part of the body through blood and generally affect the physiology of distantly situated cells. These hormones are also known as circulatory hormones.
2. Tissue hormones:-
These hormones are restricted to the tissue fluid and do not circulate with blood. Such local hormones affect the physiology of nearby target cells. Tissue hormones that affect secretary cells only are called autocrine. On the contrary, Such tissue hormones which affect the other cells found near the secretory cells are called paracrine.
Properties of hormones:-
- Each hormones acts on a particular tissues or organ to produce a specific change of affects a particular funcation.
- Hormones do not affect the organ in which they are produced but have their effect in parget organs or tissues situated away from their production sites.
- They produce very high biological response hence secreted in very small amount. For example one gram adrenaline hormone can stimulate the hert of 10 million frogs and one gram insulin can reduce the blood sugar level in 1.25 lac rabbits.
- Molecules of most of the hormones are small and have less molecular weight. Therefore they are easily diffused form blood into cells and tissues.
- Hormones are not stored in the body rather liver and kidney quickly remove then form the blood and decompose. Their continuous secretion into the blood is essential to maintain their proper concentration for a lasting effect.
- Most of the hormones are not species specific. hence hormones produced by different animals can be used for therapeutic purpose.
- some hormones produce a quick response like adrenaline while some other have their effect after a lag period like estrogens. (HORMONES AND TYPES)