Endocrine system is also known as gland system. There are different glands in the human body. These glands are secreting different hormones and enzymes. The secreted hormones and enzymes travel throughout the body by ducts and blood. Exocrine glands andendocrine glands are the two types of the endocrine system.
A. Exocrine Glands
Exocrine Glands produce and releaseessential substances such as sweat, tears, saliva, and digestive juices. These substances are known as hormones and enzymes. The produced hormones and enzymes travel to relative organs through ducts. Sweat glands, lacrimal glands, slavery gland, inammaryglands, and liver are the examples of exocrine glands.
B. Endocrine Glands
The glands without ducts or tubes are endocrine glands. The secreted hormones and enzymes by these glands are released directly into the blood and travel to tissues and organs all over the body. The introduction and functions of endocrine glands are given below.
a. Pituitary Gland
Pituitary gland is located in the middle of th e brain and just below the cerebrum. The average length and breadth of pituitai·y gland is 12 millimetres and 8 millimetres respectively. It weighs about 500 milligrams. It is called the master gland because it comman ds and controls the other endocrine glands. It plays a vital role in the growth of the body. It activates the inammary glands to produce inilk during pregnancy and after child birth. It controls the blood pressure and water retention in the body. It stimulates adrenal glands. It also helps to produce sex hormones.
b. Pineal Gland
The pineal gland is a tiny gland which is located in the nliddle of the brain. It is shaped like a tiny pea. The function of the pineal gland is to produce melatonin hormone that plays a role in managing our sleep-wake cycle.
c. Thyroid Gland
The thyroid gland is located at the base of the neck. It looks like a butterfly in shape. It produces thyroxine hormone. This hormone regulates vital body functions such as breathing, heartbeat, digestion rate, and body temperature. It also controls the growth of the bones and muscles. Similarly, it helps in mental development.
d. Parathyroid Gland
There are four parathyroid glands at the back of the thyroid. It releases parathormone hormone. The main function of this hormone is to control calcium levels in the blood. It also manages the balance in the levelof phosphorus and calcium in the body. It has a vital role in the growth and development of bones.
e. Adrenal Gland
The adrenal gland is the triangular-shaped gland located on top ofboth kidneys. It has two parts. The covering part is acortex and the inner part is a inedulla. The cortex and medulla secrete corticosteroids and adrenaline hormones respectively . These hormones affect digestive activity, heart rate, the amount of oxygen in the blood, and sexual activity.
f. Thymus Gland
The thymus gland is located inside the chest and protected by chest bones. It produces white blood cells called lymphocytes. It develops
an antibody in our body that helps our irnmune system fight the
disease and infection.
g. Gonad
Gonad is a sex gland or reproductive gland. The male one is known as the testis and the female one is the ovary. The testis releases the testosterone hormone. It helps to produce sperms. It is also responsible for the development of male characteristics such as growing moustaches, growing hairs under the arms, growing pubic hairs, deep voice, and enlargement of the penis.
The primary function of the ovary is to secrete estrogen and progesterone hormone. Estrogen plays a role in producing ova. It is also responsible for the developn1ent of female characteristics such as growing hairs under the arms, growing pubic hairs, and enlargement of breasts. On the other hand, progesterone prepares a suitable environment to implant and grow the fertilized ovum.It supports the fetus to develop and grow in the uterus. It also helps to produce milk after child birth.
h. Pancreas
Pancreas is located below the abdomen which is attached to the duodenum of small intestine. It is called mixed gland because it performs both functions ; functions of exocrine and endocrine glands. It releases the digestive juice as the exocrine gland, whereas it produces insulin and glucagon hormone as endocrine glands. These hormones control the sugar level in the blood.
Functions of Endocrine System
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It helps in circulation, respiration and digestion.
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It helps to control the body temperature in the body.
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It absorbs the essential nutrients.
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It plays a vital role in the growth and development of the bones.
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It develops the immune system to protect from disease and infection by producing antibodies.
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It helps the reproductive process by producing sex hormones.