The glands of the system secrete chemical substances that are collectively known as . these chemicals diffuse into the bloodstream and communicate with distant cells called cells.

The correct answer will be option-

1. Endocrine glands

2. Hormones

3. Target cells

Explanation:

Animal cells communicate with each other through one of the signalling ways: autocrine, Paracrine and endocrine signalling.

Endocrine signalling occurs when a chemical is secreted by a cell acts on a target cell which is distant from the producer cell.

The group of cells called tissues (glands) which secretes the chemical is thus known as an endocrine gland and the chemical secreted by the endocrine gland is known as the hormone.  

A hormone acts on the distant cell after it gets diffused in the bloodstream and gets transported to the target cell.

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