What type of tissue are all glands in the body primarily composed of?

Glands in the body are primarily composed of epithelial tissue. This type of tissue is specialized for secretion and absorption, which is essential for the function of glands. Epithelial tissue forms the protective outer layer of the body and lines internal organs and cavities. It's structured to form sheets or membranes, allowing it to effectively produce and release hormones, enzymes, and other substances.

The composition of glands as epithelial tissue facilitates various functions: for instance, endocrine glands secrete hormones directly into the bloodstream, while exocrine glands release their products through ducts to the surface of an organ or to outside the body. This characteristic of epithelial tissue makes it integral to the functioning of all types of glands, establishing their primary role in maintaining the body's biochemical balance and responding to physiological needs.

Other tissue types, such as connective tissue, nervous tissue, and muscle tissue, serve different primary functions and are not the main components of glands. Connective tissue primarily supports, binds together, and protects tissues and organs; nervous tissue is involved in transmitting signals and communication within the body; and muscle tissue is responsible for movement. While glands may contain elements of these other tissues, epithelial tissue remains the predominant component crucial to their structure and function.