1. INTRODUCTION TO THE MUSCULAR SYSTEM Part 1: Functions, Properties & Muscle Types

2. OBJECTIVES  Explain the main functions of the muscular system  Explain the 5 major properties of muscular system  Explain the 3 types of muscles

3. FUNCTION OF THE MUSCULAR SYSTEM  The primary function is to provide movement for the body  Muscle receive their ability to move the body through the nervous system

4. 5 PROPERTIES OF THE MS 1.Excitable or irritable …They are capable of receiving stimulation and responding to stimulation from the nerves 2.Contractible …They are capable of contracting or shortening after receiving stimulation 3.Extensible …A muscle can be stretched without damage by the application of force

5. 5 PROPERTIES OF THE MS 4.Elasticity …A muscle is able to return to its original resting shape and length after being extended or contracted 5.Adaptability …It can be changed in response to how it is used …A muscle can enlarge (hypertrophy) through increased work …A muscle can waste away (atrophy) if deprived of work

6. MUSCLE DEFINED  Is an organ that can contract in a coordinated fashion and includes muscle tissue, blood vessels, nerves and connective tissue  Two different controls of muscles: …Voluntary: is movement that is controlled consciously such as moving arms and legs. …Involuntary: is movement that is controlled without conscious thought such as contraction of the stomach wall

7. MUSCLE TYPES  Three types of muscle tissue: …Skeletal …Smooth …Cardiac

8. SKELETAL MUSCLE  Is responsible for moving parts of the body …For example: your limbs, trunk, & face  It is made up of elongated cells called muscle fibers  Each fibers contains many nuclei and is crossed by light and dark stripes called striations  Skeletal muscle fibers are grouped into dense bundles called fascicles  These fascicles are bound together by connective tissue to form a muscle  Skeletal muscle is voluntarily controlled

9. SKELETAL MUSCLE

10. SMOOTH MUSCLE  Forms the walls of the stomach, intestines, blood vessels and other internal organs  Individual cells are spindle shaped, have a single nucleus, and interlace to form sheets  It lacks striations and is surrounded by connective tissue  It is involuntarily controlled

11. SMOOTH MUSCLE

12. CARDIAC MUSCLE  Makes up the walls of the heart  It is striated and is involuntarily controlled  The junction of one cell with another in a particular chain is known as an intercalated disc …It appears as a heavy dark line running across the fiber cylindrical shape  Each cell has a somewhat cylindrical shape with one centrally-located, oval nucleus.  Cross-striations are apparent but they are not as regular nor as prominent as those of skeletal muscle

13. CARDIAC MUSCLE Intercalated Disc Oval-shaped nucleus