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Chemical Coordination and Integration

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CBSE Gujarat Board Haryana Board

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Class 10 Class 12
 Why is the endocrine system considered a chemical extension of the nervous system ?

The functions of the body are controlled and coordinated by nervous system. However, the chemical control is done by the hormones secreted by endocrine glands. The hormones are chemical messengers and regulators.
For example the hypothalamus, which is a part of nervous system secretes TSH-RH (Thyroid stimulating hormone - releasing hormone). The hormone is transported to pituitary gland where it stimulates anterior pituitary to secrete Thyroid stimulating hormone TSH. The TSH in turn stimulates the thyroid gland to secrete thyroxin. Thus, endocrine system and nervous system operate in coordination and many functions of the endocrine system are under control of nervous system. The two are collectively called as neuro-endocrine system. Thus, endocrine system is a chemical extension of nervous system.

Name the endocrine gland which is H shaped.

Thyroid gland.

Name the largest endocrine gland.

Thyroid gland.

Why is the Parathyroid hormone called hypercalcemic hormone?

PTH or parathyroid hormone is also called hypercalcemic hormone as it increase the calcium level in the blood.

Name the cells that the thyroid gland is composed of.

The thyroid gland is composed of the following :
i. Follicles
ii. Stromal tissue

What is goitre?

Goitre is the condition in the the thyroid gland is enlarged and the neck portion becomes swollen .It is due to the deficiency of iodine in our diet which results in the less production and secretion of the thyroid hormones that is hypothyroidism.