Transcript The Muscular System

The Muscular
System




The ability to move is an
essential activity of the
human body
½ our body weight comes
from muscles
Consists of over 600
individual muscles.
3 purposes:
– Body movement
– Body shape
– Body heat (maintain temp.)
The Muscular
System

Body movements
are determined by
three types of
muscles
– Smooth (involuntary)
– cannot be
controlled by will.
– Cardiac – control the
contractions of the
heart.
– Skeletal (Voluntary)
– can be controlled
by will.
Function of Skeletal muscles

Attach to bones to provide voluntary
movement
– Tendons: strong, tough connective cords
– Fascia: tough, sheet-like membrane
Produce heat and energy for the body
 Help maintain posture
 Protect internal organs
 Called striated (striped) because they have
striations of alternating light and dark
band

Functions cont’d.
Fleshy body parts are made of skeletal
muscles
 Provide movements to the limbs, but
contract quickly, fatigue easily and lack
the ability to maintain contraction for long
periods

– Blinking eyes, talking, breathing, eating,
dancing and writing all produced by these
muscles
Function of Smooth Muscle




Called smooth muscle because they are
unmarked by striations, small spindle shaped
Unattached to bones, act slowly, do not tire
easily and can remain contracted for a long
time
Not under conscious control so they are also
called involuntary muscles
Found in walls of internal organs (intestines,
bladder, stomach, uterus, blood vessels)
Function of cardiac muscle
Found only in the heart
 Involuntary muscle
 Requires a continuous supply of oxygen to
function
 Cardiac muscle cells begin to die after 30
seconds of oxygen cut-off
 Striated and branched

Special muscles

Sphincter (dilator) muscles are openings
between
– the esophagus and stomach
– The stomach and small intestines
– Walls of the anus, urethra and mouth

Open and close to control passage of
substances
Characteristics of Muscles

All muscles have 4 common characteristics
– Excitability – ability to respond to a stimulus
(ie: nerve impulse)
– Contractibility – muscle fibers that are
stimulated by nerves contract (become
shorter) and causes movement
– Extensibility – ability to be stretched
– Elasticity – allows the muscle to return to its
original shape after it has been stretched
Sources of heat/energy
When muscles work, they produce heat
that our body needs to function properly
 Major source of this energy is ATP – a
compound found in muscle cells
 ATP requires muscle cells to have oxygen,
glucose and other materials circulated by
the blood
 When the muscle is stimulated, ATP is
released, thus producing heat

Definitions

Adduction:

– Moving a body part
toward the midline


– Increasing the angle
between two bones or
straightening the body
part
Abduction:
– Moving a body part
away from the midline

Rotation:
– Turning a body part
around its own axis
Flexion:
– Decreasing the angle
between two bones or
bending body parts
Extention:

Circumduction:
– Moving in a circle at a
joint

Buildup of lactic acid caused by vigorous
exercise where blood is unable to be
transported:
– MUSCLE FATIGUE

State of partial contraction is called:
– MUSCLE TONE

Loss of muscle tone occurs when muscles are
not used for a long period of time. Muscles
atrophy (shrink in size and lose strength) and
results in:
– CONTRACTURES
 Foot drop is the most common type of contracture
seen, but fingers, knees and other joints can be
affected
MUSCLES YOU NEED TO KNOW
THE FUNCTIONS OF:







Biceps – flexes lower arm
Deltoid – abducts arm; injection site
Sternocleidomastoid – turns head
Gastrocnemius – flexes sole of feet
Latissimus dorsi – extends & adducts upper arm
Pectoralis major – adducts and flexes upper arm
intercostals – moves ribs for breathing
Trapezius – extends head, moves shoulder
 Triceps – extends lower arm
 Gluteus maximus – extends thigh;
injection site
 Sartorius – abducts thigh, flexes leg
 Vastus lateralis – extends leg
 Rectus abdominus – compresses the
abdomen
 Rectus femoris – flexes thigh & extends
lower leg
 Tibialis anterior – flexes and inverts foot


FIBROMYALGIA

MUSCULAR
DYSTROPHY
Chronic, widespread
pain in specific muscle  Group of inherited
diseases that cause
site; numbness and
chronic, progressive
tingling in arms or
muscle atrophy
legs; headaches
resulting in total
 Cause unknown
disability and early
 Treat symptoms –
death
pain relief; stress
 No cure
reduction and muscle
 Treatment used to
relaxers
slow progression of
disease


MYASTENIA GRAVIS

Chronic condition where
nerve impulses are not
transmitted correctly
leading to progressive
muscular weakness and
paralysis; affects
respiratory muscles and
can be fatal
Cause unknown
Treatment is supportive



MUSCLE SPASMS/CRAMPS

Sudden, painful
involuntary muscle
contractions
Caused from overexertion,
low electrolytes or poor
circulation
Treat by applying gentle
pressure and stretching of
the affected muscle


STRAIN
 Overstretching of a
muscle or tendon
frequently in legs,
back or arms
 Caused by sudden
muscle exertion
 Treated by resting,
muscle relaxants, or
pain medications,
elevation of extremity
and applying hot/cold
compresses

RANGE OF MOTION
????? WHY ?????
Done to maintain health of the
musculoskeletal system (muscle/skeleton)
 Each joint and muscle is moved through
its full range for patients with limited
ability to move
 Administered by: PT, RN, Assistant, or
other authorized personnel (with training)
 Done to prevent problems caused by lack
of movement

Problems from lack of movement

Contractures
– Tightening and shortening of a muscle resulting in a
permanent flexing of a joint

Muscle atrophy
– Muscles become weak and joints become stiff

Circulatory impairment
– Blood clots and pressure ulcers can develop

Mineral loss
– Especially calcium from the bones making bones
brittle and easily to be fractured

Other problems
– Poor appetite; constipation; urinary infections;
respiratory problems; and pneumonia
Types of ROM

Active ROM
– Performed by patients who are able to move each
joint without assistance

Active assistive ROM
– Patient actively moves the joints but receives
assistance to complete the entire range

Passive ROM
– Another person moves each joint for a patient who is
not able to exercise

Resistive ROM
– Exercises are performed by a PT against resistance
Definitions
Abduction – moving away from midline
 Adduction – moving toward midline
 Flexion – bending of body part
 Extension – straightening of body part
 Rotation – moving around its own axis
 Circumduction – moving in a circle at a
joint

Principles to follow









Movement should be slow and smooth
Support provided to the parts above and below
the joint being exercised
Never force a joint beyond its ROM or to the
point of pain
STOP if a person complains of pain
Perform each movement 3-5 times
Encourage patient to assist as much as possible
Prevent patient exposure
Keep door closed and patient screened off
Use correct body mechanics
Body Mechanics
4 main reasons…
Muscles work best when used correctly
 Correct use of muscles makes lifting,
pulling and pushing easier
 Prevents unnecessary fatigue and strain
therefore, saves energy
 Prevents injury to self

8 rules of good body mechanics
Maintain broad base
of support (8-10 in.)
 Bend from hips and
knees to get close to
object
 Use strongest
muscles: shoulders,
arms, hips, thighs
 Use weight of body to
help push/pull

Carry heavy objects
close
 Avoid twisting body;
turn whole body
when changing
direction
 Avoid bending for
long periods
 Get help if object is
too heavy
