The Muscular SystemThe Muscular System

Support SystemsSupport SystemsSupport SystemsSupport Systems

Unit 2Unit 2

Functions of the Muscular SystemFunctions of the Muscular System

• Heat Production (thermogenesis)

– Heat is a byproduct of muscle

contraction

• Movement Facilitation

– Muscles shorten and pull on bones – Muscles shorten and pull on bones

which produces movement

• Structure (postural support)

– Contraction of muscles keeps us

upright and maintains posture

Functions cont.Functions cont.

• Protection of Internal Organs – Contraction of abdominal muscles causes them to

become hard and offers protection to the underlying

organs

– Other muscles con contract prior to receiving a blow

thus protection bones and soft tissue.

• Controls the volume of hollow • Controls the volume of hollow

organs– Smooth muscle surrounds our hollow organs and

contractions propel the substances through them, aid

in their emptying, or helps control their volume

• Stomach and small intestines

• The bladder

• Blood vessels

Anterior Skeletal Muscles

Anterior Skeletal Muscles

Anterior Skeletal Muscles

Anterior Skeletal Muscles

Posterior Skeletal Muscles

Posterior Skeletal Muscles

Posterior Skeletal Muscles

Posterior Skeletal Muscles

Cardiac Muscle

• Striated – appears striped

under a microscope

• Involuntary- no conscious

control

• Found in the heart

Smooth MuscleSmooth Muscle

• Located in walls of hollow internal surfaces such as:

– blood vessels -stomach

– urinary bladder -– urinary bladder -intestines

• Non-striated in appearance

• Involuntary

Skeletal MuscleSkeletal Muscle

• Attached to

bones

• Striated

appearance

under a under a

microscope

• Voluntary control

(conscious

control)

Diseases and Diseases and

Disorders of the Disorders of the

Muscular SystemMuscular SystemMuscular SystemMuscular System

TendonitisTendonitis

• Characterized by Inflammation of the tendons due to overuse or age-related changes of the tendon.

• Common in individuals • Common in individuals who begin a new exercise or increase their level of exercise.

• Treatment includes: rest, ice, compression, and elevation (RICE).

StrainsStrains

• A tearing of a muscle or

its attaching tendon

• Occurs when a muscle

receives a stress that

overcomes its strengthovercomes its strength

– Sudden, quick heavy

lifting

– During sports

– While performing work

tasks

Strains cont.Strains cont.•• 3 types of strains3 types of strains

–– A 1A 1stst degree occurs when the muscle is stretched degree occurs when the muscle is stretched

causing microcausing micro--tears in the muscle fiberstears in the muscle fibers

–– A 2A 2ndnd degree strain occurs when the muscle or degree strain occurs when the muscle or

tendon is partially torntendon is partially torn

–– A 3A 3rdrd degree strain occurs when the muscle is degree strain occurs when the muscle is –– A 3A 3 degree strain occurs when the muscle is degree strain occurs when the muscle is

completely rupturedcompletely ruptured

•• Signs & symptoms include:Signs & symptoms include:

–– Pain, especially when the muscle is contracting Pain, especially when the muscle is contracting

which limits functionwhich limits function

–– SwellingSwelling

–– BruisingBruising

•• Treatment includes Rest, Ice, Compression, Treatment includes Rest, Ice, Compression,

ElevationElevation

Muscle SpasmMuscle Spasm

• An involuntary muscle contraction

• Also called a “Charlie Horse” or

“muscle cramp”

• Main causes are electrolyte

imbalances, dehydration and imbalances, dehydration and

fatigue

Muscle Spasm cont.Muscle Spasm cont.

• Initial treatment is to put the muscle

that has the spasm on stretch

– If spasm persists ice or heat can be

used

• Prevention incudes maintaining a • Prevention incudes maintaining a

proper diet, drinking plenty of water

and proper conditioning

– Sports drinks may be beneficial

during exercise to help replace lost

sodium due to sweating

Muscular DystrophyMuscular Dystrophy

• An inherited disorder in which

the muscles are missing a

certain protein causing

degeneration of muscle tissue

• Causes progressive weakness • Causes progressive weakness

and loss of function of the

affected muscles

• There is no cure but physical

therapy can lessen the severity

of the disorder.