Final answer:
Muscle tissue enables movement, posture maintenance, and heat generation, with excitability, contractility, conductivity, extensibility, and elasticity as its key characteristics. It is classified into skeletal, cardiac, and smooth muscle, each with distinct roles in the body.
Step-by-step explanation:
Muscle tissue facilitates movement, maintains posture, and generates heat. Muscle cells are known for their excitability; they can respond to stimuli. They are also contractile, meaning they can shorten and create force, which, when the muscles are attached to bones, result in motion.
Additionally, muscles help in maintaining posture by a sustained partial contraction and generate heat through muscle contractions, contributing to body temperature regulation. As for the characteristics, muscle tissue is conductive, with the ability to propagate electrical signals; extensible, meaning it can stretch without damage; elastic, allowing it to return to its original shape after being stretched or contracted; and contractile, capable of producing tension and shortening in response to stimulation.
Muscle tissue is categorized into three types: skeletal muscle, which is responsible for voluntary movements and is attached to bones; cardiac muscle, found in the heart, pumping blood through the circulatory system; and smooth muscle, located in various internal organs, facilitating involuntary movements.