10/2/2015 Muscular System Muscles for Locomotion

October 2, 2015October 2, 2015October 2, 2015 Engage Tennis Ball Muscle Activity

October 2, 2015October 2, 2015October 2, 2015 Explore Chicken Wing Dissection The major function of the muscular system is to support our body in movement. Through observations and class discussion, you will make deduction about certain principles of muscle function.

October 2, 2015October 2, 2015October 2, 2015 Explore “Multitalented Muscles” Web Search

October 2, 2015October 2, 2015October 2, 2015 Explain What are some functions of the Muscular System? Contract and relax to move the body. Stores energy Protects internal organs

October 2, 2015October 2, 2015October 2, 2015 Two Muscle Categories Involuntary –NOT under conscious control Voluntary –Under conscious control

October 2, 2015October 2, 2015October 2, 2015 Think About It!! Can you think of one body function that you perform without thinking about it? –Breathing, Heart Beating, Digestion, etc… How about one that one must think about? –Picking up a pencil, walking, running, etc…

October 2, 2015October 2, 2015October 2, 2015 Three Types of Muscles Smooth Muscle Cardiac Muscle Skeletal Muscle

October 2, 2015October 2, 2015October 2, 2015 Smooth Muscle Where  lining of Internal Organs and Blood Vessels Involuntary Non striated Function  Squeeze, exert pressure by slow and prolonged contractions

October 2, 2015October 2, 2015October 2, 2015 Cardiac Muscle Where  Heart Involuntary Striated and branched

October 2, 2015October 2, 2015October 2, 2015 Skeletal Muscle Majority of muscle in the body VoluntaryStriated Found attached to the skeleton by TENDONS.

October 2, 2015October 2, 2015October 2, 2015 Questions What are the two categories of muscles? What are the three types of muscles? Muscle that contract under conscious control are _________. ______ attaches muscle to bone.

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Skeletal Muscle Structure

October 2, 2015October 2, 2015October 2, 2015 Skeletal Muscle Structure Muscle - made of bundles Bundles- many muscle fibers Muscle Fiber – many myofibrils Myofibrils- filaments (thick or thin) Thick filaments –myosin protein Thin filaments –actin protein Thick and Thin give striated look

Skeletal Muscle Structure

October 2, 2015October 2, 2015October 2, 2015 Functional Unit of Muscle Sarcomere –Section of myofibril

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Muscle Contractions

Actin pulled Cross-bridge releases actin Cross-bridge changes shape Myosin returns to original shape Myosin forms cross-bridge with actin Cycle Diagram

October 2, 2015October 2, 2015October 2, 2015 Muscle Contractions

Actin pulled Cross-bridge releases actic Cross-bridge changes shape Myosin returns to original shape Myosin forms cross-bridge with actin Cycle Diagram

October 2, 2015October 2, 2015October 2, 2015 Muscle Attachment to Bone Muscles attached to bone by tendons. Muscles are attached in opposing pairs. One Muscle contracts to raise the limb, while the second will contract to lower it. Bicep / Triceps

Movement Biceps (relaxed) Triceps (contracted) Biceps (contracted) Triceps (relaxed) Figure Opposing Muscle Pairs Section 36-2

October 2, 2015October 2, 2015October 2, 2015 Muscle Strength and Exercise Strength DOES NOT depend upon the number of fibers. Why? Born with all fibers we will have. Depends on the THICKNESS of fibers and how many contract at one time

October 2, 2015October 2, 2015October 2, 2015 Muscle Soreness After Exercise Do muscle cells need O 2 ? –Yes!!! Do muscle cells need ATP? –Yes!!! Working out moderately provides us enough oxygen (aerobic) to change glucose into ATP –Called _________ respiration Working out rigorously does not allow us to get enough O 2 in our blood. What happens with no O 2 (anaerobic)? Lactic Acid Fermentation Lactic Acid builds up in muscle cells passes into the blood stream, causes the blood to become acidic, stimulates breathing, and can cause cramping

October 2, 2015October 2, 2015October 2, 2015 Regular Exercise Improves functioning of muscles Aerobic training can affect a muscle’s ability to share and use energy Increases endurance and thickness of muscle filaments (strength)

October 2, 2015October 2, 2015October 2, 2015 Elaboration The Universe Within Watch the coordination of several different body systems and how they make Mike Powell the world’s greatest long jumper. Muscle Builders! Using various materials, you will build a model that simulates muscle contractions and relaxations. This model depicts one muscle working in isolation, but as we have learned, muscles in the body cooperate in a group effort, like in the chicken wing.