Chapter 8 The muscular system

Objectives Compare the 3 types of muscle Describe 3 functions of muscle Describe how skeletal muscle contracts List substances needed in muscle contraction and describe function of each Define oxygen debt Describe 3 compounds stored in muscle List effects of exercise on muscles Compare isotonic and isometric contraction Explain how muscles work in pairs Explain how muscles are named Name some of the major muscles in each muscle group and describe main function Describe effects of aging on muscles List some muscular disorders WORD ANATOMY!!!

Types of muscle 3 types Smooth Cardiac Skeletal

We will focus on skeletal muscles THE MUSCULAR SYSTEM We will focus on skeletal muscles There are 3 primary functions of skeletal muscle: Movement Maintenance of posture Generation of heat

Structure of muscle Muscles are arranged into muscle fibers and are arranged into bundles called fascicles Endomysium surrounds individual fibers Perimysium surrounds each fascicle Epimysium is around entire muscle TENDONS are the band of connective tissue that attaches muscle to bone!

Key terms/Concepts: Motor Unit Neuromuscular Junction Neurotransmitter Synapse Motor End Plate Action Potential Actin/Myosin Sarcomere Troponin/Tropomyosin Impulses come from the CNS stimulate muscle fibers Motor impulses Made up of neuron and muscle fibers Neuromuscular Junction Contraction Calcium Muscle cells in action

Energy sources All muscle contraction requires energy in the form of ATP Myoglobin, Glycogen, Creatine Phosphate Oxygen Consumption Lactic Acid Oxygen Debt

Exercise and muscle contraction Effects of Exercise Increase in number of capillaries Increase in number of mitochondria Increase in reserves of myoglobin, glycogen and creatine phosphate Types of Muscle Contraction Isotonic (tone or tension stays the same but the whole muscle shortens) Isometric (no change in muscle length but increase in tension)

Muscles working together Prime Mover Antagonist Synergist Levers and Mechanics

Skeletal Muscle groups Muscles are named using different characteristics and grouping them according to body regions. Location for nearby bone or position Size Shape Direction of fibers Number of attached points Action Skeletal Muscle groups

Need to know muscles from these groups: Head and Neck Upper Extremities Trunk Lower Extremities

Muscular disorders/diseases Seizure Colic Strain Sprain Atrophy Muscular dystrophy Myasthenia gravis Myalgia (- associated structures: bursitis, bunions, tendinitis, shinsplints, carpal tunnel syndrome)

Don’t forget to study medical terms (roots, prefixes and suffixes) WORD ANATOMY!!! Don’t forget to study medical terms (roots, prefixes and suffixes)