ENDOCRINE SYSTEM
● The endocrine system is a network of glands and organs that produce hormones that regulate
many bodily functions like development, metabolism, and response to injury, stress, and mood.
● There are two types of glands in our body- exocrine and endocrine. The exocrine glands pour
their secretions (enzymes) into the bloodstream via ducts whereas the endocrine glands pour
their secretions called hormones into the bloodstream.
● Hormones – They are the chemical messengers produced by one part of the body and they travel
to other parts of the body through blood where they help control how cells and organs do their
work.
Some major parts of the endocrine system include:
1. Thalamus – It is present within the brain below the cerebral cortex. It acts as a relay station that
receives all the information from the body's senses (except smell) and processes it before being
sent to your brain's cerebral cortex for interpretation. It plays a significant role in learning and
memory, reasoning and problem solving.
2. Hypothalamus - Located at the base of the brain, above the pituitary below the thalamus. It acts
as the body's smart control coordinating center to keep your body in a state called homeostasis.
3. Pituitary gland - It is located at the base of the brain, behind the bridge of the nose. It is known
as the "master gland" because it produces hormones that control many other endocrine glands
and bodily functions. It has two main lobes, the anterior lobe, and the posterior lobe, each of
which produces different hormones.
Growth hormones: This is secreted by Pituitary (master gland). It regulates overall
growth and development.
4. Thyroid gland - Located in the front of the neck and secretes thyroxine. It regulates the
metabolism of carbohydrates, fats, and proteins.
5. Parathyroid glands - Located on the back of the thyroid glands, these glands secrete
parathyroid hormone, which increases blood calcium levels
6. Adrenal glands - These glands are located on the top of each kidney, produce over 150
hormones, including adrenaline, which triggers the fight or flight response.
7. Pancreas - Part of both the endocrine and digestive systems, this organ produces both digestive
enzymes and insulin. Insulin hormone reduces and regulates blood sugar level.
8. Ovaries - In women, these organs produce estrogen and progesterone, which help develop
breasts at puberty, regulate the menstrual cycle, and support pregnancy.
9. Testes - In men, these organs produce testosterone, which helps to develop secondary sexual
characters at puberty.
Importance of iodine
Iodised salt is an essential part of thyroxine hormone secreted by thyroid gland. So, we must
consume iodized salt which is necessary for proper working of thyroid gland. Its deficiency
causes a disease called goiter (Swollen neck).
Diabetes
Diabetes is a disease in which blood sugar level increases. The disease is caused due to the
deficiency of insulin hormone secreted by pancreas. Injections of insulin hormone can help in the
treatment of diabetes.
Feedback Mechanism
The excess or deficiency of hormones has a harmful effect on our body. Feedback mechanism
makes sure that hormones should be secreted in precise quantity and at right time.
Example: Feedback mechanism to control the sugar level in blood is as follows
Note: No need to draw these diagrams. Just for information
