Types of hormone in human endocrine system biology discussion
Answers
Endocrine Glands of Human Beings (with diagram)
I. Pituitary Gland:
II. Thyroid Gland:
III. Parathyroid Glands:
IV. Adrenal Gland (Suprarenal):
V. Pancreas:
VI. Testis:
VII. Ovary:
VIII. Placenta:
answer
Human Endocrine Glands!
Hormones are secreted by the endocrine glands, which are ductless glands.
We shall now loam about some important endocrine glands in the human body.
Pituitary gland:
The pituitary is a small gland attached to the ventral side of the brain. The pituitary is the most important endocrine gland, as it secretes a number of hormones that regulate various functions of the body. It also controls the functioning of the other endocrine glands. Therefore, it is called the master gland of the body.
The pituitary gland consists of two main parts—the anterior lobe and the posterior lobe. The anterior lobe secretes various hormones. One of these is the growth hormone which regulates growth and development of the body. It promotes the growth of bones and muscles when the body is growing.
An excessive secretion of this hormone leads to gigantism, an abnormal condition of excessive growth. On the other hand, insufficient secretion of the growth hormone in childhood retards growth, leading to dwarfism, an abnormal condition of stunted growth.
The anterior lobe of the pituitary gland also secretes hormones that influence the secretion of milk in the mammary glands, the production of sperms in males and the maturing of ova (eggs) in females. Two types of hormones are secreted by the posterior lobe of the pituitary. One of these helps in childbirth and the other influences the reabsorption of water in the kidney.
Pineal gland,
It is a small gland attached to the dorsal side of the brain. It has light-sensitive cells. It controls the biological clock (the timing mechanism by which an organism controls regular activities such as sleeping).
Thyroid gland:
Thyroid is a large gland located behind the larynx (voice box) in the neck. The main hormone secreted by this gland is thyroxin, which contains iodine. Thyroxin controls the metabolism of carbohydrates, fats and proteins, and brings about balanced growth.
Excessive secretion of thyroxin is called hyperthyroidism. It increases the general metabolism of the body. As a result, fat stored in the body is depleted and there is a loss of body weight.
Insufficient thyroxin secretion is called hypothyroidism. It lowers the general metabolism of the body and increases body weight. By slowing down metabolic activity, hypothyroidism retards body growth and brain development in children
When the thyroid gland becomes overactive and secretes excess thyroxin, it becomes enlarged. As a result, the neck swells up and the eyeballs bulge outward. This is called exophthalmia goiter. Swelling of the thyroid may also be due to the deficiency of iodine in the diet. This is called simple goiter. To prevent this it is important for us to have iodized salt in our diet. Iodine is needed for the synthesis of thyroxine.
Parathyroid glands:
These are two pairs of small glands buried in the thyroid gland. They secrete parathormone, which increases the level of calcium in the blood by taking out calcium from the bones. A certain amount of calcium in the blood is essential for functions such as muscular activity and blood clotting.
Thymus gland:
This gland, located near the heart, is present in new-born babies. It gradually becomes smaller with age and is degenerated or lost in the adult. It produces WBCs which fight infection.
hope it is helpful....................*****