Download MUSCULAR SYSTEM

The Muscular System
Muscles
1. How many muscles are there in the
human body?
650 Muscles
2. How do muscles work?
Muscles are bundles of muscle fibers held
together by connective tissue.
When the muscles contract, they pull on
the tendons which pull on the bones
causing our limbs to move.
Muscles
• Muscles are either voluntary or
involuntary.
Consider your arm moving to write down
class notes. You control this movement.
VS.
Your heart which beats 60 to 80 beats
every minute without you having to think
about it!
Characteristics of Muscle
Excitability – response to nerve impulse
Contractibility – fibers contract, becoming
short and causing movement
Extensibility – ability to be stretched
Elasticity – returning to its original shape after
being stretched
Functions of Muscles
•
•
•
•
Attach to bones to provide movement
Produce heat and energy
Help maintain posture
Protect internal organs
Types of Muscles
 Cardiac
 Visceral
 Skeletal
Muscle Characteristics
• A difference between skeletal and smooth
muscles is that skeletal muscles are made
of tissue fibers that are striated or striped
(bands of light and dark). Smooth muscle
fibers are not striated.
• The cardiac or heart muscle (also called
myocardium) is a unique type of muscle
that does not fit clearly into either of the
two classes of muscle. Like skeletal
muscles, cardiac muscles are striated.
But like smooth muscles, they are
involuntary, controlled by the autonomic
nervous system.
Skeletal
Smooth
Cardiac
Cardiac and Visceral Muscles
Cardiac Muscles
form the walls of
heart and contracts
to circulate blood
through out the
body.
Visceral Muscles
(smooth muscles)
are found in internal
organs such as the
digestive and
respiratory systems.
Also, these muscle
are found in the eyes
and blood vessels
Skeletal Muscles
• Skeletal Muscles attach bones which
causes body movement.
Involuntary Muscles
• Both cardiac and visceral muscles are
classified as involuntary muscles. These
muscles function without our conscious
control.
Voluntary Muscles
• Skeletal muscles are classified as
voluntary muscles because a person has
control over its action.
Types of Attachments
TENDONS:
• Strong, tough connective tissue cord
• EXAMPLE: Achilles Tendon which attaches to
the gastrocnemius muscle on the calf of the leg
to the heel bone
FASCIA:
• Tough, sheetlike membrane
• Covers and protects
• EXAMPLE: Lumbodorsal Fascia
which surrounds the trunk and
back
Origin and Insertion
• When muscles attach to bones, one end
becomes the origin and one end becomes
the insertion.
ORIGIN: End that does not move
INSERTION: End that moves when
the muscle contracts
Intramuscular Injection Site
• The Deltoid Muscle
is the most common
injection site. This
site is for older
children and adults.
Also, this is the site
where the flu shot is
given.
Other Intramuscular Injection
Sites
• Vastus Lateralis –
muscle located on side of
thigh, site used on infants
and small children and
where vaccines are given
• Gluteus Maximus –
muscle in buttocks, site
used on older children
and adults and where
pain shots are given
Front View of
Muscles
Side View of
Muscles
1 = Biceps Brachii
2 = Pectoralis Major
3 = Rectus Abdominis
4 = Sartorius
5 = latissimus dorsi
6 = trapezius
7 = gluteus maximus
8 = serratus anterior
9 = triceps
10 = gastrocnemius
Movements of Muscles
• ADDUCTION: Moving a body part toward
the midline (moving arm or leg to middle of
body)
• ABDUCTION: Moving a body part away
from the midline (moving arm or leg away
from body)
• CIRCUMDUCTION: Moving body part in a
circle
Movement of Muscles
• FLEXION: Decreasing the
angle between two bones or
bending a body part
• EXTENSION: Increase the
angle between two bones or
straightening a body part
• ROTATION: A circular motion
that turns a body part on its axis
Muscle Tone
• Partially contracted at all times
• Muscle tone allows for state of readiness
Loss of muscle tone can occur when a person is
paralyzed. If a muscle is not used for a long
period of time, it will atrophy (shrink in size and
lose strength).
Lack of use can also result in a contracture, a
severe tightening of the flexor muscle causing a
bending of the joint. Foot drop is a common
contracture.
Muscle Facts
• The Masseter Muscle which closes the jaw
with chewing is the strongest muscle in the
body.
• The Sternocleidomastoid Muscle turns the
head.
• The Trapezius Muscle lifts the shoulder.
• The Biceps Brachii Muscle flexes the arm.
• The Triceps Brachii Muscle extends the arm.
More Facts
• The longest muscle in the body is
___________
Answer: The Sartorius
• The Sartorius runs from the outside of the
hip, down and across to the inside of the
knee. It twists and pulls the thigh outwards.
More Facts
• The smallest muscle in the body is _________
Answer: The Stapedius
• The Stapedius is located deep in the ear. It is
only 5mm long and thinner than cotton thread.
This muscle is involved in hearing.
More Facts
• The biggest muscle in the body is ________
Answer: The Gluteus Maximus
• The Gluteus Maximus is located in the
buttock. It pulls the leg backwards and
is used with walking and running.
DID YOU KNOW?
There are 60 muscles in the face.
Smiling is easier than
frowning.
It takes 20 muscles to smile and over 40 to
frown.
Muscles at a Glance
http://www.kidport.com/RefLib/Science/Hum
anBody/BodyMuscles.htm
Muscle Quiz
http://www.e-learningforkids.org/Courses/Liquid_Animation/Body_Parts/Muscles/index.html
Muscle Pain
Muscle Injuries
Muscle cramps
Caused by over
stretching muscles,
or by abnormal muscle
contraction. They may
also be associated with
loss of fluid due to
excessive sweating.
SYMPTOMS
pain, tenderness, loss of power and stiffening, or
spasms of the muscles
TREATMENT
• Rest, application of an ice pack,
then subsequent gentle stretching.
• DO NOT massage the
affected muscles.
Muscle Strain
• Overstretching or injury to
a muscle and/or tendons
• Frequent sites include the
back, arms, and legs
• Prolonged or sudden
muscle exertion is usually
the cause
Muscle Strain
SYMPTOMS
• Myalgia or muscle pain
• Swelling
• Limited movement
TREATMENT
• Rest and elevation of extremity
• Pain medications
• Alternating heat and cold applications
So what is a Sprained Ankle?
• A sprained ankle
involves the
stretching or tearing
of ligaments.
• So a sprain involves
ligaments while a
strain involves
muscles.
Treatment for a Sprain
Chest cramps
“stitches”
Usually caused by cramps of the
intercostals muscles between the ribs
SYMPTOMS
Brought on by exertion, chest cramps are
identified by sharp, spasmodic pain in the
chest, difficulty in standing upright, and
gasping respirations
TREATMENT
• A “Stitch” will disappear with rest
and by taking deep breaths.
Tennis Elbow
This injury is due to a strain of the
tendons and muscles associated with
the elbow. Severe cases also involve
the ligaments. It is usually a chronic
condition, and presents when the
elbow is over-used or over-stretched.
Symptoms:
TREATMENT
Apply Ice pack
and support in a
sling.
Pain over the bone
on the outer side of
the joint that becomes
more severe on
movement
Disease:
MUSCULAR DYSTROPY
• Group of inherited muscular diseases
• Leads to a chronic progressive muscle
atrophy
• Usually appears in early childhood
• No cure and most types result in total
disability and early death
• Physical Therapy is used to slow
progress
Disease: MYASTHENIA GRAVIS
• Chronic condition in which nerve impulses
are not transmitted properly to the
muscles.
• Leads to progressive muscular weakness
and paralysis
• Can be fatal when it affects the respiratory
muscles
Disease: MYASTHENIA GRAVIS
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•
•
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Considered an Autoimmune Disease
Antibodies attack the body’s own tissue
No cure
Treatment is supportive of symptoms
Medical Story
http://www.huffingtonpost.com/2009/10/15/di
sease-turns-muscle-into_n_322162.html
Boy with rare disease that turns
muscle into bone.