Final answer:
The three types of muscles in the human body are skeletal muscles, which allow voluntary movements, cardiac muscles, which form the heart and contract involuntarily, and smooth muscles, which are found in internal organs and also move involuntarily.
Step-by-step explanation:
Human bodies contain three distinct types of muscle tissue. These are: skeletal muscles, cardiac muscles, and smooth muscles. Each type has a unique structure and function.
- Skeletal muscles are the ones we can control voluntarily. They are attached to bones by tendons and enable us to make conscious movements.
- Cardiac muscle forms the walls of the heart. This muscle makes the heart contract and beat without conscious thought.
- Smooth muscle is found in the walls of internal organs such as the stomach, intestines, and blood vessels. These muscles work involuntarily to move substances through the body.
Muscle contraction starts with an action potential that activates myofilaments within the muscle cells. These myofilaments, made of the proteins actin and myosin, are organized in units called sarcomeres. During contraction, myosin and actin fibers slide past each other, shortening the muscle fiber and generating movement.