The Muscular System

1. The Muscular System Chapter 7

2. Muscular System Your muscular system is the group of structures that make your body parts move. Muscle tissue specializes in contraction (shortening)

3. Muscle Structure Muscles are organs, which are groups of cells and tissues working together. All of your muscles make up the muscular system, one of your body’s many organ systems. Muscles have nerve tissue in them to tell them when and how to do their jobs.

4. Muscle Classification • Muscles are classified into two basic groups in your body: • Voluntary • Skeletal • Involuntary • Smooth • Cardiac

5. Muscle Classification • Voluntary Muscles: • These muscles you can control by thinking about it. • Involuntary Muscles: • These are muscles that you cannot control. • They work without you even thinking about it. • Exception: breathing • You can control your breathing if you think about. However, you’ll keep breathing even if you don’t think about it.

6. Voluntary vs. Involuntary • Skeletal Muscle • Is muscle attached to bones that enables you to move your body. • Voluntary Muscle • Look like it has stripes (striated)

7. Voluntary vs. Involuntary Smooth muscle Cardiac muscle non striated tapered at each end make up digestive tract • heart muscle • intercalated disks • Striated • involuntary

8. Types of Muscle Tissues

9. Structure of the Skeletal Muscle Origin – the muscle’s attachment to this more stationary bone Insertion – muscle’s attachment to the more moveable bone Tendon – connects the muscle to the bone

10. Muscle Structure • The basic functional unit of a muscle is a sarcomere. • A sarcomere is made up of two kinds of protein filaments called actin and myosin.

11. Sarcomere Actin Myosin Thin myofilament Protein Thick myofilament Protein

12. Sliding Filament Model • Actin and myosin filaments slide past each other and that makes a sacromere contract. • Thick filaments attach to thin filaments using cross bridges that pull the thin filaments toward the center of the sarcomere.

13. Muscle Structure • Muscle cells are often called muscle fibers. • Groups of muscle fibers are wrapped together inside a special covering made of connective tissue. • Bundles of muscle fibers are grouped together to form muscles.