Human endocrine gland

Hypothalamus

• It is located in the diencephalon in the brain. It is known for producing hormones like oxytocin and antidiuretic hormone.
• Hypothalamus is responsible for controlling the pituitary gland, and hence it is called the control centre.
• Oxytocin and vasopressin hormones are produced by the hypothalamus and secreted into the blood directly. 

Pituitary gland

• It is one of the most important human endocrine glands responsible for producing several hormones.
• It is controlled by the hypothalamus and is known as the master gland.
• It is further divided into the anterior and posterior pituitary gland, and each is known for releasing its set of hormones.

Hormones released by the anterior pituitary gland

1. Growth hormone supports a person’s normal growth.
2. Prolactin supports the growth and development of the mammary glands and hence controls milk secretion in lactating women.
3. Gonadotropic hormone regulates the secretion of hormones like oestrogen in females and testosterone in males.
4. Thyroid-stimulating hormones stimulate the thyroid gland for the secretion of thyroid hormone.
5. Adrenocorticotropic hormones stimulate adrenal glands for the secretion of the hormones.

Hormones released by the posterior pituitary gland

1. Oxytocin helps with uterine contraction during childbirth.
2. Vasopressin is known for reabsorption of water from the nephron and concentrates the urine.

Thyroid gland

• The thyroid is the largest endocrine gland.
• It is nearly 5cm in diameter, bilobed in structure and located below the larynx attached to the trachea.
• It is responsible for the production of T4 (thyroxine) and T3 (triiodothyronine)
• Thyroid hormones are responsible for regulating the metabolic process in the body. 

Parathyroid gland

• The gland is present in pairs, oval in shape, and located above the thyroid gland.
• It is known for the release of parathyroid hormones, which helps with balancing the calcium and phosphate level in the blood. 

Thymus

• The gland is pinkish, large during puberty, but its size shrinks with age.
• It is known to secrete thymosin which helps in the formation of the WBCs, lymphocytes and hence helps with fighting infection. 

Pancreas

• It is a part of both digestive systems and is a crucial human endocrine gland located behind the stomach.
• The pancreas produces hormones that promote digestion. Two important hormones released by the pancreas are insulin and glucagon.
• The Islets of Langerhans are the endocrine cells. The ß-cells secrete the insulin, and α-cells secrete glucagon. 

Adrenal gland

• The human endocrine gland is a pyramid-shaped gland located above the kidneys.
• The adrenal glands are known for releasing corticoids which are: 

1. Glucocorticoids help with the process of carbohydrate metabolism.
2. Mineralocorticoids help with maintaining the mineral balance.
3. Sex-corticoids help with the maintenance of external sex characteristics.

The hormones released by the adrenal gland helps in controlling blood pressure, heart rate, maintaining a level of salt in the body, promoting sex hormone production etc.  

Pineal Glands

• It is a small gland located in the brain which is responsible for the production of melatonin hormone.
• The hormone produced by the pineal gland is known to regulate sleep patterns, stimulate the immune system, prevent cancer cell growth, etc.

Gonads

It includes the male and the female sex organs which are:

• Testes are a paired structure responsible for the production of testosterone which supports development of secondary sexual character in males.
• Ovaries are the female gonad which is known for producing female hormones like oestrogen and progesterone.