© 2009 Delmar, Cengage Learning Chapter 7 Muscular System.

© 2009 Delmar, Cengage Learning

Chapter 7

Muscular System

© 2009 Delmar, Cengage Learning

Functions of Muscular System

• Body heat to maintain body temperature

• Body movement

• Body form and shape to maintain posture

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Types of Muscles

• Skeletal muscle– Under conscious control

• Smooth muscle– Not under conscious control

• Cardiac muscle– In the heart only

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Animation – Typesof Muscle Tissue

Click Here to play Types of Muscle Tissue animation

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Characteristics of Muscles

• Contractibility

• Excitability or irritability

• Extensibility

• Elasticity

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Muscle Attachmentsand Functions

• Over 650 muscles in the body

• Muscles must be attached to bones for leverage

• Muscles only pull, never push

• Attached to bone by tendons

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Muscle Attachmentsand Functions

• Muscles are attached at both ends

• Attachments may be to bones, cartilage, ligaments, tendons, skin or to each other

• Origin and insertion

• Prime mover and antagonist

• Synergists

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Sources of Energy and Heat

• Narrow range of normal body temperature

• 98.6 °F to 99.8°F

• ATP (adenosine triphosphate)– Need oxygen, glucose, and other material to make

– By-product is lactic acid

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Contraction of Skeletal Muscle

• Myoneural stimulation

• Contraction of muscle proteins

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Effects of Aging

• Muscle atrophy

• Fibrous tissue replaces the muscle tissue

• Decrease in muscular strength and endurance

• Loss of energy storage– Fatigue

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Muscle Fatigue

• Caused by accumulation of lactic acid in the muscles

• When not enough oxygen can be transported to oxidize all the glucose

– Muscles contract anaerobically

• Excess lactic acid causes fatigue and cramps

• Need to repay oxygen debt

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Muscle Tone

• Muscle tone– Muscles are always slightly contracted and ready to pull

• Proper nutrition and regular exercise

• Isotonic

• Isometric

• Atrophy and hypertrophy

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Principle Skeletal Muscles

• Skeletal or voluntary muscles– Move the skeleton

• Also control movement of the eyeballs, eyelids, lips, tongues, and skin

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Naming of Skeletal Muscles

• Location

• Size

• Direction

• Number of origins

• Location of origin and insertion

• Not all muscles are named by above method

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Muscles

• 656 muscles

• 327 antagonistic muscles and two unpaired muscles

– Orbicularis oris

– Diaphragm

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Muscles

• Head muscles

• Neck muscles

• Trunk and extremity muscles

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Muscles of the Head and Neck

• Control expressions

• Mastication

• Movement of the head

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Muscles

• Muscles of the upper extremities– Shoulder, arm and hand movements

• Muscles of the trunk– Breathing and movement of the abdomen and pelvis

• Muscles of the lower extremities– Thigh, leg, ankle, foot, and toes

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Exercise

• Alters the size, structure, and strength of a muscle

• Atrophy

• Hypertrophy

• Scar formation from injury

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Exercise

• Improved coordination

• Improved respiratory and circulatory system

• Elimination or reduction of excess fat

• Improved joint movement

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Exercise

• Increase in muscle size

• Improved antagonistic muscle coordination

• Improved functioning in the cortical brain region, where the nerve impulses that start muscular contraction

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Massage Muscles

• Potential health benefits

• Terms used in massage therapy to describe type of massage

• Location of surface body muscles

• Physiotherapy and general massage

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Electrical Stimulation

• Passing electrical currents through the skin into the body for therapeutic uses

• Stimulate nerve tissue

• Do not produce heat or cold

• Used in physical therapy

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Intramuscular Injections

• Deltoid (upper arm)

• Vastus lateralis (anterior thigh)

• Dorsal gluteal or ventral gluteal (buttocks)

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Musculoskeletal Disorders

• Muscle atrophy

• Muscle strain

• Muscle spasm

• Myalgia

• Hernia

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Musculoskeletal Disorders

• Flatfeet (talipes)

• Tetanus (lockjaw)

• Torticollis (wry neck)

• Muscular dystrophy

• Myastenia gravis

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Recreational Injuries

• Tennis elbow

• Shin splints

• Rotator cuff disease

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Treatment

• Short term treatment for sprains, tears, pulls

and other minor muscle of joint injuries

• RICE– R – Rest

– I – Ice

– C – Compression

– E – Elevation