Introduction to Endocrine System:

Endocrine System

Endocrine System

The endocrine system is the system of glands of the human body. Each of these glands secretes one or more different hormones in the blood for different functions. The secretions of endocrine glands are known as hormones. Each endocrine gland may secrete one or more hormones in the blood and these hormones may or may not have related functions. Generally, the hormones regulate different functions of the human body like growth, mood, development, and metabolism etc. They perform their function by attaching to the target cells and then communicating with them.

Endocrine Glands:

Endocrine glands are ductless glands of the human body that pour their secretions (hormones) directly into the blood. They have three characteristic features that are:

  1. They are ductless
  2. They are highly vascularized
  3. They possess intracellular vacuoles or granules that store the hormones

In contrast to the endocrine glands are the “exocrine glands”. The see a detailed explanation of the difference between endocrine glands and exocrine glands.

Endocrine glands of Human Body:

Endocrine glands of the human body are divided into two categories;

1) Typical endocrine glands,

2) Organs having the secondary endocrine function

1) TYPICAL ENDOCRINE GLANDS: These glands have a primary function of producing hormones for the human body. Typical endocrine glands include;


Typical Endocrine Glands of body

Typical Endocrine Glands

2) ORGANS HAVING SECONDARY ENDOCRINE FUNCTION: These organs primarily belong to some other system of the body but have a secondary function of producing hormones. They include;

  1. PANCREAS(Hormones of Pancreas)
  2. OVARIES (In females) (Hormones of Ovaries)
  3. TESTES (In males) (Hormones of Testes)
  4. KIDNEYS (Hormones of Kidneys)
  5. LIVER (Hormones of Liver)

Functions of the endocrine system:

As stated above, the endocrine system is a regulatory system of the human body. In fact, it associates the nervous system in controlling body functions. The control of body function by the nervous system is called nervous coordination and the control of body functions by the endocrine system is called chemical coordination. The control of body functions by the endocrine system is a long-term control system. All the necessary changes and adaptations of the body, required for the long-term control of a specific function, are influenced by the hormonal system.


Endocrine System Outline:

Typical Endocrine Glands
Pituitary Gland Master gland of the body, It has two lobes, Present at the base of the brain in form of a protrusion, Secretes 9 different major hormones
Thyroid Gland One of the largest glands of the body, Found in the neck below the thyroid cartilage, Mainly controls body metabolism, Secretes 3 different hormones
Parathyroid Glands Four in number, located behind the thyroid gland, produce parathormone
Adrenal Glands Found attached to the kidneys, Consists of two parts; Cortex and Medulla, Adrenal cortex produces 3 different hormones and adrenal medulla produces 4 different hormones
Organs with Secondary endocrine function
Pancreas Primarily an organ of the digestive system produces 4 different hormones including Insulin and Glucagon
Gonads Primarily organs of the reproductive system, Testes in males produce testosterone, Ovaries in females produce Estrogens and Progesterone
Liver Primarily a metabolic organ of human body, produces 3 different types of hormones
Kidneys Primarily an organ of the Excretory system, Produces 4 different types of hormones
Functions Generally it parallels the associates the nervous system in control of body activities, Each hormone has a specific function,