The Muscular System Basics
Ever wondered why your heart keeps beating even when you're asleep? That's because you've got two main types of muscles working in your body. Voluntary muscles are the ones you consciously control - like flexing your biceps or kicking a football. These skeletal muscles attach directly to your bones and let you move around.
Involuntary muscles are the clever ones that work automatically without you thinking about them. They contract on their own and include both smooth muscles (found in your digestive system and internal organs) and cardiac muscle (your heart). Your brain controls cardiac muscle through special regions, but you never have to consciously tell your heart to beat.
The connection system is pretty straightforward: tendons attach muscles to bones, whilst ligaments connect bones to other bones. When a muscle contracts, it pulls on the bone through the tendon, creating movement at the joint.
Skeletal muscles work in pairs to produce different types of movement like flexion and extension. Think about your arm - your biceps contracts to bend your elbow (flexion), whilst your triceps contracts to straighten it (extension).
Quick Tip: Remember the difference - tendons connect muscle to bone (think "T" for tendon and "to"), whilst ligaments link bone to bone!