TISSUES

A chapter on tissue in biology may cover the following topics: Definition Tissue is a group of cells that work together to perform a specific function. The word "tissue" comes from the French word tissu, which is the past participle of the verb tisser, meaning "to weave". Organization Tissue is a biological organizational level that falls between cells and organs. Organs are formed by grouping multiple tissues together. Types There are four types of tissue in animals: connective, muscle, nervous, and epithelial. Study The study of tissues is called histology, and the study of disease-related tissues is called histopathology. Tools The classical tools for studying tissues are the paraffin block, histological stain, and optical microscope. Examples Columnar epithelium is a type of tissue that lines organs like the intestines, helping with absorption and secretion. Nervous tissue is made up of neurons, neuroglia, and neurosecretory cells.