Download the muscular system

THE MUSCULAR SYSTEM
HEALTH TERMS:
Smooth Muscles- type of muscle concerned with the movements of internal organs.
Skeletal Muscles- the striped, or striated, muscles attached to bones that cause body
movements.
Flexors- muscles that close a joint
Extensors- muscles that open out a joint
Cardiac Muscle- a special type of striated tissue that forms the walls of the heart
Muscle Tone- the natural tension in the fibers of a muscle
Tendonitis- the inflammation of a tendon
Hernia- a protrusion of an organ or tissue through a weak area in the muscle
FUNCTIONS of the MUSCULAR SYSTEM:

Responsible for all body movement

Pumps blood throughout body

Moves food through Digestive System

Controls movement of air in and out of the lungs
CLASSIFICATION of MUSCULAR MOVEMENT:

Voluntary- movement under conscience control—walking, talking, reaching

Involuntary- automatic movement—breathing, digesting, blinking
MUSCULAR CONTRACTION (Structure):

Skeletal Muscles work by means of two complimentary/ opposing actions
o Contraction- shortening of muscle fibers
o Extension- stretching of muscle fibers
(Contraction/ Extension is triggered by nerve impulses)
o Muscles that close a joint are called FLEXORS

o Muscles that open a joint are called EXTENSORS
Contraction Diagram:
o Skeletal Muscles= Striated
o Striation = Striped
● Nerve impulses are sent to the muscle from the brain.
●
Skeletal Muscle Make-up
o Each stripe is made up of Muscle Cells –linked together
o Each Muscle Cell is made up of Muscle Fibers
o Each Muscle Fiber is made up of Myofibrils
o Each Myofibril is made up of two types of Proteins—Actin & Myosin

The impulse jumps from the motor end plates onto the muscle striations

If the impulse sends the message to Contract, the Actin & Myosin jump on top
of each other, sending a chain-reaction
o Myofibrils shorten,
o Fibers shorten,
o Cells shorten,
o Striations shorten,
o Muscle contracts

If the impulse sends the message to Extend, the Actin & Myosin repel each
other, sending a chain-reaction
o Myofibrils lengthen
o Fibers lengthen
o Cells lengthen
o Striations lengthen
o Muscle extends
TYPES of MUSCLE:

Skeletalo Muscles attached to bones
o Striated= striped
o Form the largest part of the body’s muscular system
o More than 600 muscles
o Voluntary

Cardiaco Special type of Striated tissue that forms the walls of the heart
o Most important muscle in the body
o Responsible for pumping blood through body
o Contracts rhythmically ~ 100,000 times/ day
o Involuntary

Smootho Named for smooth structure
o Forms internal organs—intestines, bladder, pleura of the lungs, walls
of blood vessels
o Involuntary
CARE of MUSCULAR SYSTEM:

Exercise Regularly
o Must use Muscle regularly
 Risk of “Atrophy”—waste away
 Use it or Lose it
o Build Muscle Tone—natural tension in the muscle fibers
o Warm up, Stretch and Cool down when exercising

Eat Well Balanced, Nutritious Meals
INJURY to the MUSCLES:

Muscle Ache
o Due to Lactic Acid Build-up—also results in cramps and knots
o Temporary condition

Strain
o
o
o
o
Pulled muscle
Result from overexertion
Most common in athletes
Treatment consists of R.I.C.E. method

Bruise
o Discolored area under the surface of the skin caused by leakage of
blood after an injury
o Sore or painful to the touch
o Treatment = ice or cold pack reduces pain and possible swelling of
affected area

Tendonitis
o Inflammation of a tendon
o Caused by overuse
o Symptoms include pain, tenderness and restricted movement of muscle
attached to affected tendon
o Treatment may include anti-inflammatory medication, ultrasound, or
injection of corticosteroids.

Hernia
o More serious muscle injury
o Protrusion of an organ or tissue through a weak area in the muscular
wall
o Can occur when one lifts an object that is too heavy
o Treatment usually results in surgery to repair injured area
ILLNESSES to the MUSCLE:

Myasthenia Gravis
o A disorder in which the muscles become weak and easily fatigued
o Eye muscles are most commonly affected
 Droopy eyelids
 Double vision

Muscular Distrophy
o An inherited disorder characterized by a progressive wasting away of
skeletal muscles
o Early detection is crucial
o No Cure
o Muscle weakening can be delayed by regular exercise