The Muscular System Lesson 1 3 Classification How

The Muscular System Lesson 1. 3

Classification: How Muscles Work Voluntary Muscles • Muscles that are under your direct control • Examples: –Skeletal muscles (biceps, triceps etc. )

Classification: How Muscles Work Involuntary Muscles • Muscles that are not under your conscious control. They work automatically without you thinking about it. • Involuntary muscles are found in: –The stomach and intestines –The heart –Blood vessels

Classification: Types of Muscles Three types of muscle tissue: • skeletal muscle • smooth muscle • cardiac muscle

Skeletal Muscle • Attached to the bones of your skeleton. • Voluntary muscles – muscles you have conscious control of. • Provide the force that moves your bones. • Work in pairs • React quickly and tire quickly. • Tendons - strong connective tissue that attaches muscles to bones. • Ligaments – strong connective tissue that connects bones together at joints

Smooth Muscle • involuntary muscles - they work without your conscious effort. Smooth muscles are found in: • The stomach • The intestines

Cardiac Muscle • Involuntary muscles • Found only in the heart. • Do not get tired. A Cardiac Muscle Cell

How Do Muscles Work? Muscles work by contracting, or becoming shorter and thicker. – Muscle cells can only contract, not extend – Skeletal muscles must work in pairs. • One muscle contracts • the other muscle in the pair relaxes and returns to its original length. To bend arm: biceps muscle contracts triceps relaxes. To straighten arm: triceps muscle contracts biceps muscle relaxes

https: //www. youtube. com/watch? v=V Cminz-X 52 I • Video on animation of muscles

How Do Muscles Work? Flexor: the muscle that contracts to bend your arm or leg Extensor: the muscle that contracts to straighten your arm or leg To bend arm: biceps muscle contracts triceps relaxes. To straighten arm: triceps muscle contracts biceps muscle relaxes

Anatomy of a Muscle

Think Act Share Which muscle is the extensor muscle in your arm? Which muscle is the flexor in your arm? Is the flexor muscle in your thigh in the front or the back?