Unit H1: Personal Management

Part 1: Muscle Physiology

Overview Muscular System Role & Importance Types of Muscle Tissue Skeletal Muscle Structure Function Examples in the body

Muscle System Why do we have muscles? Brainstorm using a concept map as many of the different roles that muscles perform for the body Some of the Roles of the Muscular System: 1. Create motion at the joints 2. Assist organs 3. Move food throughout the digestive system (persistalsis) 4. Allow us to breathe 5. Moves blood throughout the body by pumping the heart 6. Assist the veins in returning blood to the heart 7. Produce heat for the body 8. Maintain healthy posture 9. Many more!

Muscle System 3 Types of Muscle Tissue: Smooth Muscle Cardiac Muscle Skeletal Muscle All muscle tissue has the ability to? 1. Contract 2. Relax 3. Stretch 4. Return to original shape

Smooth Muscle Where is it found in the body? Lines some of the organs of our body Examples: bladder, stomach Within the walls of our blood vessels Lining the trachea and respiratory tract The iris of the eye What does it do? Smooth muscles provide involuntary control We can not think about these muscles and contract or relax them when we want to Why is this a good thing?

Smooth Muscle Cells

Cardiac Muscle Where is it found in the body? Only in the walls of the heart Attaches to itself! What does it do? Contracts and relaxes in order to pump blood throughout the body Like smooth muscle, cardiac muscle is involuntary Why?

Cardiac Muscle Cells

Skeletal Muscle Where is it found? Surrounding the joints of our entire body Accounts for 40% of your body weight! Mr G’s muscle mass is 72lbs (32kg)! What most of us think of when we say “muscle” What does it do? Primary role is to provide motion at the joints for all of the body movements we need to perform By moving the skeleton! Also helps generate heat, provide stability, and maintain posture

Skeletal Muscle Cells

Skeletal Muscle: Structure Made of special proteins which are grouped together into myofibrils. Myofibrils are joined together in bundles, known as muscle fibers. Many muscle fibers are bundled together to form the muscle belly The muscle belly is connected to bone at either end by tendons = a special connective tissue

Skeletal Muscle: Function Remember: skeletal muscle is connected on either end to bones Skeletal muscle moves the bones of the body by contracting (shortening) or relaxing (lengthening) This creates movement at the joints Example: Elbow flexion What muscles are involved? What bones are involved? How are the bones being moved? Muscles work in pairs at each joint. When one is contracting (prime mover), the other is relaxing (antagonist).

Elbow FlexionElbow Extension Biceps Brachii Prime Mover Contracts (gets shorter) Triceps Brachii Antagonist Relaxes (gets longer) Biceps Brachii Antagonist Relaxes (gets longer) Triceps Brachii Prime Mover Contracts (gets shorter)

Skeletal Muscle: Function In addition to the prime mover – antagonist pair of muscles, there are usually several supporting muscles that contract to stabilize the joint = Stabilizers For example, during elbow flexion the brachioradialis helps stabilize the elbow joint.