Health Occupations
Muscular System – Unit 1
Muscle
Location
Frontalis
Temporalis
Above nose & eyes
Temples
Orbicularis Occuli
Masseter
Around eye
Jaw
Function
Raises eyebrows
Closes the jaw
Closes eye
Clenches teeth
Closes lips, kisses
Extends head, shoulder
Turns & flexes head
Abducts arm, injection
Adducts & flexes arm
Extends lower arm
Moves scapula
Flexes lower arm
Extends, adducts arm
Orbicularis Oris
Trapezius
Sternocleidomastoid
Deltoid
Pectoralis
Triceps
Serratus
Anterior biceps
Lattisimus dorsi
Around lips
Upper back & neck
side of neck
Shoulder
Upper chest
Upper arm
Ventral lower ribs
Upper arm
Spine around to chest
Rectus abdominis
Exterior oblique
Ribs to pubis
Compresses abd
Lower abd/pelvis (lat) Bends/rotates vertebrae
Sartorius
Rectus femoris
Vastus lateralis
Vastus medialis
gastrocnemius
Tibialis anterior
Front of thigh
Front of thigh
Lateral thigh
Medial thigh
Back of lower leg
Bicep femoralis
Front of lower leg
Back of thigh
Gluteus maximus
buttocks
Achilles tendon
Back of calf
Abducts & flexes
Extends leg
Extends knee
Extends knee
Flexes sole of foot
Flexes & inverts foot
Flexes knee, lat rotate thigh, extends
hip
Extends thigh, injection
Allows calf to function
Frontalis
Trapezius
Sternocleidomastoid
Deltoid
Pectoralis
Triceps
Serratus
Biceps
Latissmus dorsi
Rectus abdominus
Exterior oblique
Rectus femoris
Vastus lateralis
Vastus medialis
Sartorius
Gluteus maximus
Gastrocnemius
Tibialis anterior
Achilles tendon
Muscular System
Made up of over 600 muscles
 Organs – bundles of muscle fibers held
in place by connective tissue
 Contraction

– Movement of muscles when stimulated

Tonus
– Muscle’s ability to maintain slight &
continuous contraction
Muscular System

Types of stimulation
– Electrical
– Mechanical
– Chemical

When not contracted, muscles are
FLACCID or soft
Properties of muscles

Excitability
– Irritability, ability to respond to a stimulus such as
a nervous impulse

Contractility
– Ability to shorten forcefully when stimulated

Extensibility
– Ability to be stretched

Elasticity
– Ability to recoil to its resting length when relaxed
Functions of muscle
Aids in movement
 Provides & maintains posture
 Protects internal organs
 Provides movement of blood, food, &
wastes through the body
 Opens & closes body openings
 Produces heat

Types of muscle tissue
Muscle type
Appearance
Manner of
control
Skeletal
Striated
Voluntary
Visceral
Smooth
Involuntary
Cardiac
Indistinctly
striated
involuntary
Skeletal Muscle





>40% of body weight
Increases in size & weight with exercise
Decreases in size & weight with inactivity
Variety of sizes & shapes due to genetics,
nutrition, & exercise
Tendons – attach muscles to bone
– Narrow strips of dense connective tissue
– Gastrocnemius
• Calf muscle attaches with the Achilles tendon to the heel
Skeletal Muscle

Fascia –
– Tough, sheetlike membrane
– Covers & protects tissue
• Deep muscles of back & trunk are surrounded by
lumbodorsal fascia

Named by:
–
–
–
–
–
Location
Related bones
Shape
Action
Size
Skeletal Muscle

Appearance
– Striated under microscope
– Made up of bundles of fine fibers
– Number of fibers doesn’t increase much
after birth
– Muscle mass increases due to increase in
fiber SIZE not number
Actions & Movements of skeletal
muscles








Adduction – toward midline
Abduction – away from midline
Flexion – decreasing angle between 2 bones
Extension – increasing angle between 2
bones
Rotation – turning a part around its own axis
Circumduction – moving in a circle @ a joint
Pronation – turning hand or foot downward or
backward
Supination – turning hand or foot upward or
forward
Flexion
Extension
Rotation
Abduction
Adduction
Supination Pronation
Sarcomere

Basic unit of muscle fibers causing muscular
contraction
 Made up of actin & myosin myofibrils
 Most contract under voluntary control
 3 parts to skeletal muscle
– Origin – the end of muscle attaching to less
moveable part of bone
– Action or body – thick, middle part of muscle
– Insertion – the end of muscle attaching to most
moveable part of bone
Sarcomere (cont)

Movement occurs by pulling bones, working
in PAIRS
– One muscle contracts
– Counteracting muscle relaxes

Prime mover – AGONIST
– Pulls to contract muscle

Antagonist muscle –
– Relaxes when agonist contracts

Synergists & fixators
– Keep muscle & bone stable during movement
Contracted
Skeletal Muscle Tissue
Relaxed
Origin
Action or body
Relaxed
Insertion
Contracted
Sarcomere (cont)

Atrophy
– Shrinking in size & loss of strength of
muscle
– Occurs when muscle is not used over time

Contracture
– Severe tightening of a flexor muscle
– Results in bending of a joint
– Foot drop is common
Visceral Muscle

Smooth, NO striations like skeletal muscle
 Contracts when stimulated
 Controlled by autonomic nervous system
 Lines various organs
– Makes up walls of blood vessels
– Found in tubes of digestive system
– Sphincter muscles (circular)
• Opens & closes pupils
• Urinary bladder
Cardiac muscle
Found only in heart
 Indistinctly striated
 Involuntary control
 Has specialized cells that provide a
stimulus for contraction - PACEMAKER

Range of Motion (ROM)

Standards
– Move each joint slowly, gently, smoothly
– Support each joint during movement
– Don’t move joint past its present level of
movement
– If pain occurs, stop movement & report
– Watch face, especially eyes, for signs of pain
– Discuss exercise plan with charge nurse
– Perform ROM on one side of body at a time
– Move each joint 5 times
ROM Procedure
Wash hands
 Identify client
 Explain procedure & ask permission to
perform skill
 Provide privacy

ROM

Shoulder
– Hold wrist & elbow
– Flexion & extension
– Abduction & adduction
– Horizontal abduction & adduction (hand to
opposite shoulder, then back out to
shoulder level)
– Rotation of elbow, up & down like hand
signal
ROM

Elbow
– Hold wrist & elbow
– Flexion & extension
– Rotation of hand, up & down towards face
& feet
ROM

Wrist
– Hold wrist & fingers
– Flexion & extension
– Hyperextension of hand
– Abduction & adduction of wrist
– Tilt Hand towards toes, bring hand, thumb
side up, towards nose
ROM

Fingers/Thumbs
– Hold hand
– Make fist to flex fingers
– Straighten fist by extending fingers
– Abduction, adduction of all fingers
– Thumb abduction, adduction
– Thumb opposition
ROM

Hip & Knee
– Hold knee & ankle
– Flexion knee & hip, extend knee, return to
resting position
– Abduction & adduction
– Rotation of leg, inward & outward
ROM

Ankle
– Hold ankle & foot
– Flexion & extension of foot
– Foot abduction & adduction
ROM

Toes
– Hold foot
– Flexion & extension of toes
– Abduction & adduction of toes

To finish
–
–
–
–
Position comfortably
Bed lowest position
Side rails up, call light in place
Wash hands