ANATOMY

Detailed explanation-1: -Hormone is a substance that directly involve in cellular communication within the human body. Explanation: A hormone is a restrictive substance created in an organism and transported in tissue fluids like blood or sap to stimulate specific cells or tissues into action.

Detailed explanation-2: -Acetylcholine is a chemical secreted at the ends of nerve cells. This chemical helps to send nerve signals across synapses (spaces between nerve cells). After the signal passes across a synapse, an enzyme breaks down the acetylcholine.

Detailed explanation-3: -In long-distance endocrine signaling, signals are produced by specialized cells and released into the bloodstream, which carries them to target cells in distant parts of the body. Signals that are produced in one part of the body and travel through the circulation to reach far-away targets are known as hormones.

Detailed explanation-4: -Hormones can be thought of as chemical messages. From the blood stream, the hormones communicate with the body by heading towards their target cell to bring about a particular change or effect to that cell. The hormone can also create changes in the cells of surrounding tissues (paracrine effect).

Detailed explanation-5: -Answer and Explanation: Hormones are intracellular messenger. Every hormone can execute its function only when it modulated the transcription of particular genes. For this, the hormones have to bind to specific recepotrs located on the target cells.