The Muscular System – Introduction

IUnit Overview Objectives What are the effects of muscles on exercise? What are the effects of exercise on muscles? How do muscles work – both macroscopically and microscopically ? How do muscles utilize energy? Labs Microscopic Structure Lab Exercise and Cell Respiration Lab Assessment Lab Analysis Questions Exam incorporating lab and lecture information

Physiology Overview Muscular System Functions Movement – by contraction/shortening Stationary Support – by contraction/shortening to maintain posture Stationary Support – by contraction/shortening to stabilize joints Generate Heat Muscles and Motion animation

Levels of Organization

IMacroscopic Overview How do muscles work? Muscles are attached to bones. All muscles cross at least one joint. Each muscle contracts or gets shorter Contraction pulls from an origin to an insertion. Each muscle produces a specific movement - ”ACTION“

I Macroscopic Overview Muscle Actions Produce Joint Movements Joint movements describe the axis in which the body part moves. They occur in pairs that produce opposite movement. Examples: flexion/extension; abduction/adduction;

IMacroscopic Overview Muscles work in pairs located on opposite sides of a joint Muscles ‘pull’- never ‘push’. They work together to undo the action of the opposite muscle of the pair. Prime mover – provides the major force for a specific movement Synergist – assist the prime mover in specific movement Antagonist – opposes or reverses the prime mover. Example: Latissimus dorsi is prime mover for arm adduction; teres major acts as synergist; deltoid acts as antagonist Deltoid is prime mover for arm abduction; supraspinatus is a synergist; latissimus dorsi is the antagonist

IMacroscopic Overview Anterior viewPosterior view

Microscopic Overview Three Types of Muscle Tissue We will focus on skeletal muscle!

Microscopic Overview Three Types of Muscle Tissue We will focus on skeletal muscle!