How many main types of tissue are there in animals?

In animals, there are four main types of tissue: epithelial, connective, muscle, and nervous tissue.

Epithelial tissue serves as a protective barrier and is involved in absorption and secretion. Connective tissue provides support and structure, connecting different parts of the body, and includes bone, blood, and adipose tissues. Muscle tissue is responsible for movement and is categorized into skeletal, cardiac, and smooth muscle, each with distinct functions and characteristics. Nervous tissue is essential for transmitting signals and processing information within the body, comprising neurons and supporting glial cells.

Understanding the four main types of tissue is fundamental to studying animal biology, as they collectively contribute to the overall function and homeostasis of the organism.