The correct option is 2 and 3 only.
Explanation
Nervous tissue is a specialized tissue responsible for the control and coordination of the body. It originates from the ectoderm and is structurally and functionally distinct from epithelial, connective, and muscular tissues.
- Statement 1 is Incorrect: Nervous tissue is not made of epithelial cells. It is primarily composed of two types of cells: neurons (nerve cells) and neuroglia (glial cells). Epithelial tissue is a separate category of tissue that covers body surfaces and lines cavities. Furthermore, nervous tissue is not "randomly arranged"; it forms highly organized networks (circuits) to process information.
- Statement 2 is Correct: The primary function of nervous tissue is to receive stimuli and transmit information throughout the body. This transmission occurs via electrical impulses (action potentials) generated by changes in the electrical potential across the plasma membrane of neurons.
- Statement 3 is Correct: Neurons are the structural and functional units of the nervous system. They are termed excitable cells because they have the unique ability to respond to stimuli by generating electrical signals. Neuroglial cells, while part of the nervous tissue, are generally non-excitable and serve to support, protect, and nourish neurons.
Key Takeaway: Nervous tissue consists of excitable neurons and non-excitable neuroglial cells, specialized for rapid communication via electrical impulses. It is distinct from epithelial tissue in both structure and function.