2. Introduction
A hormone is a chemical substance that is secreted into
the internal body fluids by one cell or group of cells and
has a physiological control effect on other cells of the
body.
4. Local Hormones
Acetylcholine released at the parasympathetic and
skeletal nerve endings.
Secretin released by the deudenal wall and transported
in the blood to the pancreas to cause a watery
pancreatic secretion.
Cholecystokinin released in small intestine and
transported to the gall bladder to cause it to contract and
to the pancreas to cause digestive enzyme secretion.
These hormones have specific local effects,
from where it comes the name local hormones.
6. Important hormones secreted by these glands and
their most important actions
Anterior Pituitary Gland
1. Growth Hormones
2. Adrenocorticotropin
3. Thyroid Stimulating
Hormones(TSH)
4. Follicle Stimulating
hormones(FSH)
5. Leuteinizing
hormones(LH)
6. Prolactin
Posterior Pituitary gland
1. Antidiuretic hormone
2. Oxytocin
I. Pituitary Gland hormones
7. 1. Growth hormone causes growth of almost all cells and
tissues of the body.
2. Adrenocorticotropin causes the adrenal cortex to secrete
adrenocortical hormones.
3. TSH causes the thyroid gland to secrete thyroxine.
4. FSH causes the growth of follicles in ovaries before
ovulation, promotes the formation of sperm in the testis.
5. Prolactin promotes development of breasts and secretion
of milk
Functions of hormones secreted from Pituitary
gland.
8. Antidiuretic hormone also called as vasopressin
causes the kidneys to retain water ,thus
increasing the water content of the body ,also in
high concentration causes constriction of blood
vessels throughout the body and elevates the
blood pressure.
Oxytocin hormone contracts the uterus during
the birthing process , thus helping expel the
baby, also contracts myoepethelial cells in the
breasts,thereby expressing milk from breast
when baby suckles.
9. II. Adrenal cortex hormones
1. Cortisol:- Cortisol for control of the metabolism of
proteins, carbohydrates and fats.
2. Aldosterone :- Aldosterone reduces sodium excretion
by kidneys and increases potassium excretion, thus
increasing sodium in the body while decreasing the
amount of potassium.
10. III. Thyroid Gland
1. Thyroxine
2. Triidothyronine :- Function of 1 & 2 increase the rates
of chemical reaction in almost all cells of the body, thus
increasing the general level of body metabolism.
3. Calcitonin:- It promotes the deposition of calcium in the
bones and thereby decreases calcium concentration in
the extra cellular fluid.
11. IV. Islets of Langerhans in the Pancreas
1. Insulin :- It promotes glucose entry into most cells of
body , in this way controlling the rate of metabolism
of most carbohydrates.
2. Glucagon :- It increases the synthesis and release
of the glucose from the liver into circulating body
fluids.
12. V. Ovaries
1. Estrogen :- It stimulates the development of the female
sex organs ,the breasts and various secondary sexual
characteristics.
2. Progesterone :- It stimulates secretion of uterine milk
by uterine endomentrial glands; also helps promote
development of secretory apparatus of the breasts.
13. VI. Testis
Testosterone:- It stimulates growth of the male sex
organs, also promotes the development of male
secondary sex characteristics.
VII. Parathyroid Gland
Parahormone :- It controls the calcium ion
concentration in the extracellular fluid by controlling
absorption from the gut , excretion of calcium by the
kidneys and release of calcium from the bones.
14. VIII. Placenta
1. Human Gonadotropin:- It promotes growth of the
corpus luteum and secretion of estrogens and
progesterone
2. Estrogens:- It promotes growth of the mother’s sex
organs and some of the tissues of the foetus.
3. Progesterone:- It promotes development of
endometrium in advance of implantation of the fertilized
ovum ; probably promotes development of some of the
fetal tissues and organs; helps promote development
of the secretory apparatus of the mother’s breasts.
4. Human somatomammotropin:- It probably promotes
growth of some fetal tissues as well as aiding in
development of the mother’s breasts.
