The main function of muscle tissue is movement, enabling the body to perform various physical activities. Muscle tissue is categorized into three types: skeletal, smooth, and cardiac. Skeletal muscle is under voluntary control and facilitates movement of the skeleton, while smooth muscle is involuntary and controls internal organs, such as the digestive tract. Cardiac muscle, found only in the heart, is also involuntary and responsible for pumping blood throughout the body. Muscle tissue contractions generate movement, maintain posture, and produce heat, making it essential for overall body functioning and interaction with the environment.