In human body there are two types of glands. The first type of glands are exocrine glands. The exocrine glands are also known as duct glands. Saliva, bile, tears are from duct glands in the body. The endocrine glands are known as ductless glands. The ductless glands secrete the secretions directly into the blood. The endocrine glands secrete hormones. The hormones in very small quantities show very big effect on the body.

The following are the endocrine glands of the body.

1. Pituitary gland and Pineal gland

2. Thyroid and para thyroid glands

3. Thymus gland

4. Pancreas

5. Adrenal glands

6. Gonads

1. Pituitary gland and Pineal gland

Pituitary gland is known as master gland of the endocrine system. That is all glands work under the control of pituitary gland. The location of pituitary gland and pineal gland is below the brain. These glands secrete different hormones.

2. Thyroid and para thyroid glands

Thyroid gland is near the throat. Thyroid secretes a hormone known as thyroxine or iodine. Deficiency of the hormone causes feeble mindedness, sluggishness, loss of memory etc., Excess of this hormone also causes loss of weight, tension, nervousness etc., Para thyroid is associated with the thyroid gland. Para thyroid controls calcium and phosphorus metabolism. deficiency causes allergies, cramps, tender bones, spasms etc.,

3. Thymus gland is present near the chest towards the heart.

4. Pancreas secretes a hormone known as insulin. It controls blood sugar levels. Deficiency of insulin causes a disease known as diabetes.

5. Adrenal glands are present on the kidneys. That is on two kidneys two adrenal glands are present. Adrenalin is know as fight flight hormone. That means if the organism is weak man fights with it. If the organism is strong man flights or escapes from it. For example if a man can escape from a dog if he is weak by running or can beat it with a stick or stone if available. Adrenalin is useful to absorb shocks. It converts glycogen to glucose. This change gives energy that comes from glucose either to fight or flight.

6. Gonads:

Gonads are different in male and female species.

In males gonads are known as testis. The testis secretes androgens or testosterone. This hormone gives male characteristics. In females the gonads are known as ovaries. ovaries secrete two types of hormones. One hormone is estrogen. The second hormone is known as progesterone. This hormone gives females the female characteristics. The changes occur during the adolescent period that is from early teens to late teens. Teenagers during this time requires special attention.

The endocrine system plays an important role in human behavior. It is a special branch of study in psychology and learning. It is surprising to note that the hormones shape the individual in many ways during his/her life from birth to death or from womb to tomb.