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Muscular System
Muscles are responsible for all types
of body movement
 Three basic muscle types are found in
the body

Skeletal muscle
 Cardiac muscle
 Smooth muscle

Characteristics of Muscle
All Muscle cells are elongated
(muscle cell = muscle fiber)
 All can contract due to the movement
of microfilaments
 All muscles share some terminology

Prefix myo refers to muscle
 Prefix mys refers to muscle
 Prefix sarco refers to muscle

Types of Muscle
Types of Muscle, cont.
Skeletal Muscle
Characteristics





Most are attached by tendons to bones
Cells are multinucleate
Striated – have visible banding
Voluntary – subject to conscious control
Cells are surrounded and bundled by connective
tissue
Characteristics of Smooth
Muscle





Has no striations
Spindle-shaped
cells
Single nucleus
Involuntary – no
conscious control
Found mainly in the
walls of hollow
organs
Cardiac Muscle
Characteristics





Has striations
Usually has a
single nucleus
Joined to another
muscle cell at an
intercalated disc
Involuntary
Found only in the
heart
Functions of Skeletal Muscles





Produce movement
Maintain posture
Stabilize joints
Generate heat

Muscle Fibers blend into a connective
tissue attachment



Tendon – cord-like structure
Aponeuroses – sheet-like structure
Sites of muscle attachment



Bones
Cartilages
Connective tissue coverings of each other
Muscle Tissue
There are three types of muscle tissue
in the body.
 Skeletal muscle is the type that
attaches to our bones and is used for
movement and maintaining posture.
Cardiac muscle is only found in the
heart. It pumps blood.
 Smooth muscle is found in organs of
the body such as the GI tract.
Smooth muscle in the GI tract moves
food and its digested products.

Skeletal Muscle
Skeletal muscle attaches to our skeleton.
 The muscle cells are long and cylindrical.
 Each muscle cell has many nuclei.
 Skeletal muscle tissue is striated. It has tiny
bands that run across the muscle cells.
 Skeletal muscle is voluntary. We can move
them when we want to.
 Skeletal muscle is capable of rapid
contractions. It is the most rapid of the muscle
types.
 No rhythmic contraction.

Cardiac Muscle








Branching cells
One or two nuclei per cell
Striated
Involuntary
Medium speed contractions
Cardiac muscle tissue is only found in
the heart.
Its speed of contraction is not as fast as
skeletal, but faster than that of smooth
muscle.
IT has rhythmic contraction
Smooth Muscle








Fusiform cells
One nucleus per cell
Nonstriated
Involuntary
Slow, wave-like contractions
Smooth muscle is found in the walls of
hollow organs. *.
*The contractions of smooth muscle
are slow and wave-like.
Some has rhythmic contraction
Connective Tissue Wrappings of
Skeletal Muscle
 Endomysium –
around single
muscle fiber
 Perimysium –
around a
fascicle
(bundle) of
fibers
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 6.1
Slide 6.4a
Connective Tissue Wrappings of
Skeletal Muscle
 Epimysium –
covers the
entire skeletal
muscle
 Fascia – on the
outside of the
epimysium
Figure 6.1
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 6.4b
Skeletal Muscle Attachments
 Epimysium blends into a connective
tissue attachment
 Tendon – cord-like structure
 Aponeuroses – sheet-like structure
 Sites of muscle attachment
 Bones
 Cartilages
 Connective tissue coverings
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 6.5
Function of Muscles
 Produce movement
 Maintain posture
 Stabilize joints
 Generate heat
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 6.8
Microscopic Anatomy of Skeletal
Muscle cell (fiber)
 The nuclri are pushed aside by
ribbonlike myofibrils
 Cells are multinucleate
 Nuclei are just beneath the sarcolemma
Figure 6.3a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 6.9a
Microscopic Anatomy of Skeletal
Muscle cell (fiber)
 Sarcolemma – specialized plasma
membrane
 Sarcoplasmic reticulum – specialized
smooth endoplasmic reticulum
Figure 6.3a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 6.9b
Microscopic Anatomy of Skeletal
Muscle cell(fiber)
 Myofibril
 Bundles of myofilaments
 Myofibrils are aligned to give distrinct bands
 I band =
light band
 A band =
dark band
Figure 6.3b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 6.10a
Microscopic Anatomy of Skeletal
Muscle
 Sarcomere
 Contractile unit of a muscle fiber
Figure 6.3b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 6.10b
Microscopic Anatomy of Skeletal
Muscle
 Organization of the sarcomere
 Thick filaments = myosin filaments
 Composed of the protein myosin
 Has ATPase enzymes
Figure 6.3c
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 6.11a
Microscopic Anatomy of Skeletal
Muscle
 Organization of the sarcomere
 Thin filaments = actin filaments
 Composed of the protein actin
Figure 6.3c
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 6.11b
Microscopic Anatomy of Skeletal
Muscle
 Myosin filaments have heads
(extensions, or cross bridges)
 Myosin and
actin overlap
somewhat
Figure 6.3d
Slide 6.12a
Microscopic Anatomy of Skeletal
Muscle
 At rest, there is a bare zone that lacks
actin filaments
 Sarcoplasmic
reticulum
(SR) – for
storage of
calcium
Figure 6.3d
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 6.12b
Striations in
Skeletal Muscle

A- Band- covers the length of the myosin filament

I- Band- covers actin where there is no overlap with
myosin

H- Zone- the portion of myosin that does not overlap
actin

Z- Line- point where actin filaments anchor
Microanatomy of Skeletal
Muscle
Each muscle cell is called a muscle fiber. Within
each muscle fiber are many myofibrils.
Z line
Z line
The sarcomere is the functional unit of a muscle cell
H Band
The area of the sarcomere has only myosin is called the H band.
Sarcomere Relaxed
The part of the sarcomere with only actin filaments is called the I band.
Sarcomere Partially
Contracted
This sarcomere is partially contracted. Notice than the I
bands are getting shorter.
Sarcomere Completely
Contracted
The sarcomere is completely contracted in this slide. The I and H bands
have almost disappeared.
Neuromuscular Components
Neuromuscular junction- the point where a
motor neuron joins muscle fibers,
Motor unit- a motor neuron and all the
muscle fibers it innervates, may be few or
hundred
All or none law-with adequate stimulation,
a muscle cell will contract to its fullest
extent or not at all
Skeletal muscle activity
Muscles have special functions
 1-Irritability : the ability to receive and
respond to stimulus
 2-Contractility : the ability to shorten
 Muscle cell must be stimulated by
nerve impulse to contract
 There is a gap (synaptic cleft)
between the nerve &muscle cell

This gap is crossed by chemical
transmitter called Acetylcholine (Ach)
 Sarcolemma becomes temporarly
permeable to sodium
 This upset generates an electric
current called action potentiual which
is unstoppable leading to contraction

MUSCLE TONE

Relaxed skeletal muscles are always slightly
contracted
 This state is termed “muscle tone”

Stretch receptors in muscles and tendons are
activated




Spinal reflexes continually activate an alternating
subset of motor neurons
No active movement produced
Muscles kept firm, healthy, and ready to respond
to stimulation
Helps stabilize joints and maintain posture
MUSCLE CONTRACTIONS
 Isotonic
contraction
 Muscle length changes and
moves the load
 Cross
bridges are moving
 Once tension is sufficient to
move load, tension remains
relatively constant
 Bending the knee, rotating the
arms and smiling are examples
ISOMETRIC CONTRACTIONS

Tension builds but muscle length
remains constant
Muscle attempts to move a load
greater than the force the muscle
is able to develop
 Try to lift your car or push against
immovable object or trying to lift
400kg are examples

Effect of exercise on Muscle
Muscles are no exceptions to the
saying –use it or lose it Regular exercise increases muscle
size, strength and endurance
 Aerobic exercise (isotonic
contraction)results in stronger muscle
with greater resistance to fatigue
 No increase in size but better heart
&lungs

Isometric(Resistance)contra
ction
Require little time
 No special equipment
 Leads to enlargement of muscle cell
without increase in their number

Energy for muscle contraction
ATP store in the muscle supplies
energy ONLY for 4-6 seconds
 ATP then comes from
1-direct phosphorylation of ADPby
reaction with creatine phosphate(CP)
-No need for oxygen
-1 ATP for 1 CP
-Provides energy for 15 seconds only

 2-Anaerobic
respiration:
glycolysis and lactic acid
formation
 -No need for oxygen
 -2ATP per glucose
 -lactic acid accumulate
 - Provides energy for 30-60
seconds only
 -after that muscle become
sluggish
3-aerobic mechanism (oxidative
phosphorylation)
 Oxygen is needed to oxidize glucose,
pyruvic acid, lactic acid, free fatty
acids and aminoacids
 36 ATP for 1 glucose
 Duration of energy is HOURS

Tetany
Sustained contraction of a muscle
 Result of a rapid succession of nerve
impulses delivered to the muscle.

Tetanus
This slide illustrates how a muscle can go into a sustained
contraction by rapid neural stimulation. In number four the
muscle is in a complete sustained contraction or tetanus.
Muscle fatigue.

Muscle fatigue occurs when an exercising
muscle can no longer respond to the same
degree of stimulation with the same degree of
contractile activity.
 Factors for this include an increase in
inorganic phosphate, accumulation of lactic
acid, and the depletion of energy reserves.
 Increased oxygen consumption is needed to
recover from exercise (paying off an oxygen
debt).
Naming Skeletal Muscle
Direction of
Muscle
Fibers
Location
Action
Skeletal
Muscle
Origin
&
Insertion
Size
Shape
Number
Of
Origins
Naming Skeletal Muscle

Direction of Muscle Fibers


Relative to the Midline
RECTUS means parallel
to midline
• Rectus Abdominus

TRANSVERSE means
perpendicular to midline
• Transversus Abdominus

OBLIQUE means
diagonal to midline
• External Oblique
• Internal oblique
Naming Skeletal Muscle
 Location
 Structure
near
which a muscle is
found
 Muscle near
 frontal bone =
Frontalis
 Muscle near the
Tibia = Tibialis
Naming Skeletal Muscle

Size


Relative Size of
Muscle
MAXIMUS means
largest
• Gluteus Maximus

MINIMUS means
smallest
• Gluteus Minimus

LONGUS means
longest
• Fibularis Longus

BREVIS means short
• Fibularis Brevis

Number of Origins


Number of tendons of
origin
BICEPS means two
• Biceps Brachii

TRICEPS means
three
• Triceps Brachii

QUADRICEPS
means four
• Quadriceps Femoris
Naming Skeletal Muscles

Shape





Relative Shape of the
Muscle
DELTOID means having
a triangular shape
TRAPEZIUS means
having a trapezoid
shape
SERRATUS means
having a saw-toothed
shape (Serratus Ant.)
RHOMBOIDEUS means
having a diamond shape
(Rhomboid Major)
Naming Skeletal Muscles

Origin & Insertion


STERNOCLEIDO
MASTOID
attaches to the
Sternum, Clavicle,
and Mastoid
Process
ILIO COSTALIS
attaches to the
ilium & ribs
Naming Skeletal Muscles
NAME
FLEXOR
EXTENSOR
ACTION
EXAMPLE
Decrease angle at a joint
Flexor Carpi Radialis
Increase angle at a joint
Extensor Carpi Ulnaris
ABDUCTOR
Move bone away from
midline
Abductor Pollicis Longus
ADDUCTOR
Move bone toward midline
Adductor Longus
LEVATOR
Produces upward
movement
Levator Scapulae
DEPRESSOR
Produces downward
movement
Depressor Labii Inferioris
SUPINATOR
Turn palm
upward/anteriorly
Supinator
PRONATOR
Turn palm
downward/posteriorly
Pronator Teres
Types of Skeletal Muscle




Prime mover (Agonist) – muscle with the
major responsibility for a certain movement
Antagonist – muscle that opposes or
reverses a prime mover
Synergist – muscle that aids a prime mover
in a movement and helps prevent rotation
Fixator – stabilizes the origin of a prime
mover
Types of body movements
–
Movement
that
decreases
angle
between 2
bones.
 Flexion
–
movement
that
increases
angle
between 2
bones
 Extension
 Abduction
–
movement
away from
the midline
of the body
Muscular System
 Adduction
–
movement
towards the
midline of
the body
Rotation – movement
around a longitudinal
axis
 Circumductioncombination of flexion,
extension, abduction,
and adduction. seen in
ball and socket joints as
the shoulder

–
occurs when
palms rotate
forward or
upward
 Supination
 Pronation
–
occurs
when
palms
rotate
downward
or
posteriorly
 Dorsiflexion
–
standing on
heal
flexion –
standing on
toes
 Plantar
Inversion
of the foot: turn the
sole medially.
Eversion of the foot: turn the
sole laterally
Opposition: moving the
thumb to touch the tips of the
other fingers
Axial and Appendicular
Muscles
Figure 11–3a
Axial and Appendicular
Muscles
Figure 11–3b
Divisions of the Muscular
System
1.
Axial muscles:



2.
position head and spinal column
move rib cage
60% of skeletal muscles
Appendicular muscles:



support pectoral and pelvic girdles
support limbs
40% of skeletal muscles
Muscles of the face
Figure 11–4a
Muscles of Facial xpression
Figure 11–4b
Extrinsic Eye Muscles

Also called extra-ocular muscles
Figure 11–5a, b
Extrinsic Eye Muscles
Inferior rectus
Medial rectus
Superior rectus
Lateral rectus
Inferior oblique
Superior oblique
Figure 11–5c
Summary: Extrinsic Eye Muscles
Table 11–3
Muscles of Mastication
Figure 11–6
3 Muscles of Mastication

Masseter:


the strongest jaw muscle
Temporalis:

helps lift the mandible
Buccinator
 flattens the cheek,hold the food
between the teeth

Summary: Muscles of the
Tongue
Table 11–5
Muscles of the Pharynx
Figure 11–8
3 Muscles of the Pharynx

Pharyngeal constrictor muscles:


Laryngeal elevator muscles:


move food into esophagus
elevate the larynx
Palatal muscles:

lift the soft palate
Summary:
Muscles of the Pharynx
Table 11–6
Anterior Muscles of the Neck
Figure 11–9
6 Anterior Muscles of the Neck






Digastric:
 from chin to hyoid
 and hyoid to mastoid
Mylohyoid:
 floor of the mouth
Geniohyoid:
 between hyoid and chin
Stylohyoid:
 between hyloid and styloid
Sternocleidomastoid:
 from clavicle and sternum to mastoid
Omohyoid:
 attaches scapula, clavicle, first rib, and hyoid
Anterior Muscles of the Neck
Table 11–7
Muscles of the Vertebral Column
Figure 11–10a
Muscles of the Vertebral
Column
Spinal extensors or erector spinae
muscles (superficial and deep)
 Spinal flexors (transversospinalis)

Superficial Spinal Extensors



Spinalis group
Longissimus group
Iliocostalis group
Deep Spinal Extensors





Semispinalis group
Multifidus muscle
Interspinalis muscles
Intertransversarii muscles
Rotatores muscles
Spinal Flexors

Neck:
longus capitis and longus colli
 rotate and flex the neck


Lumbar:
quadratus lumborum muscles
 flex spine and depress ribs

Muscles of the Vertebral Column
Table 11–8 (1 of 2)
Muscles of the Vertebral Column
Table 11–8 (2 of 2)
Oblique and Rectus Muscles
Figure 11–11a, b
Oblique and Rectus Muscles
Figure 11–11a, c
Oblique and Rectus Muscles

Oblique muscles:
compress underlying structures
 rotate vertebral column


Rectus muscles:
flex vertebral column
 oppose erector spinae

Oblique Muscles
Cervical region:
scalene muscles
 flex the neck

Thoracic region:

intercostal muscles (external and internal
intercostals):
• respiratory movements of ribs

transversus thoracis:
• cross inner surface of ribs
Oblique Muscles

Abdominopelvic region (same pattern
as thoracic):
external oblique muscles
 internal oblique muscles


Transversus abdominis
Rectus Group

Rectus abdominis:
between xiphoid process and pubic
symphysis
 divided longitudinally by linea alba
 divided transversely by tendinous inscriptions


Diaphragmatic muscle or diaphragm:
divides thoracic and abdominal cavities
 performs respiration

Summary: Oblique and
Rectus Muscles
Table 11–9 (1 of 2)
Summary: Oblique and
Rectus Muscles
Table 11–9 (2 of 2)
Functions of Pelvic Floor
Muscles
1.
2.
3.
Support organs of pelvic cavity
Flex sacrum and coccyx
Control movement of materials
through urethra and anus
Perineum

Muscular sheet forming the pelvic floor,
divided into:
anterior urogenital triangle
 posterior anal triangle

Pelvic Diaphragm
Deep muscular layer extending to pubis:
 supports anal triangle

Urogenital Diaphragm

Deep muscular layer between pubic
bones:
supports the pelvic floor
 and muscles of the urethra


Superficial muscles of the urogenital
triangle:

support external genitalia
Muscles of the Pelvic Floor
Table 11-10 (1 of 2)
Muscles of the Pelvic Floor
Table 11-10 (2 of 2)
The Appendicular Muscles
Figure 11–13a
The Appendicular Muscles
Figure 11–13b
The Appendicular Muscles
Position and stabilize pectoral and
pelvic girdles
 Move upper and lower limbs

Divisions of Appendicular Muscles
1) Muscles of the shoulders and upper limbs:
 Position the pectoral girdle
 Move the arm
 Move the forearm and hand
 Move the hand and fingers
2) Muscles of the pelvis and lower limbs
Muscles that Position
the Pectoral Girdle
Figure 11–14a
Muscles that Position
the Pectoral Girdle
Figure 11–14b
6 Muscles that Position the
Pectoral Girdle

Trapezius:
superficial
 covers back and neck to base of skull
 inserts on clavicles and scapular
spines


Rhomboid and levator scapulae:
deep to trapezius
 attach to cervical and thoracic
vertebrae
 insert on scapular border

6 Muscles that Position the Pectoral
Girdle

Serratus anterior:




Subclavius:



on the chest
originates along ribs
inserts on anterior scapular margin
originates on ribs
inserts on clavicle
Pectoralis minor:

attaches to scapula
Muscles that Position the Pectoral
Girdle
Tables 11–11
Muscles that Move the Arm
Figure 11–15a
Muscles that Move the Arm
Figure 11–15b
9 Muscles that Move the Arm

Deltoid:


Supraspinatus:


the major abductor
assists deltoid
Subscapularis and teres major:

produce medial rotation at shoulder
9 Muscles that Move the Arm

Infraspinatus and teres minor:


produce lateral rotation at shoulder
Coracobrachialis:
attaches to scapula
 produces flexion and adduction at
shoulder

9 Muscles that Move the Arm

Pectoralis major:
between anterior chest and greater
tubercle of humerus
 produces flexion at shoulder joint


Latissimus dorsi:
between thoracic vertebrae and
humerus
 produces extension at shoulder joint

The Rotator Cuff

Muscles involved in shoulder rotation

supraspinatus, subscapularis,
infraspinatus, teres minor,and their
tendons
Muscles that Move
the Forearm and Hand
Figure 11–16a
Muscles that Move
the Forearm and Hand
Figure 11–16b
Muscles that Move the Forearm and
Hand
Originate on humerus and insert on
forearm
 Exceptions:

the major flexor (biceps brachii)
 the major extensor (triceps brachii)

Extensors and Flexors

Extensors:


mainly on posterior and lateral
surfaces of arm
Flexors:

mainly on anterior and medial
surfaces
13 Muscles that Move the Forearm and
Hand

Biceps brachii:



Triceps brachii:




flexes elbow
stabilizes shoulder joint
extends elbow
originates on scapula
inserts on olecranon
Brachialis and brachioradialis:



flex elbow
originates on scapula
inserts on radial tuberosity
13 Muscles that Move the Forearm and
Hand

Anconeus:


opposes brachialis
Palmaris longus:
superficial
 flexes wrist


Flexor carpi ulnaris:
superficial
 flexes wrist
 adducts wrist

13 Muscles that Move the Forearm and
Hand

Flexor carpi radialis:




Extensor carpi radialis:




superficial
flexes wrist
abducts wrist
superficial
extends wrist
abducts wrist
Extensor carpi ulnaris:



superficial
extends wrist
adducts wrist
13 Muscles that Move the Forearm and
Hand

Pronator teres and supinator:
originate on humerus and ulna
 rotate radius


Pronator quadratus:
originates on ulna
 assists pronator teres

Tendon Sheaths

Extensor retinaculum:
wide band of connective tissue
 posterior surface of wrist
 stabilizes tendons of extensor
muscles


Flexor retinaculum:
anterior surface of wrist
 stabilizes tendons of flexor muscles

The Intrinsic Muscles of the
Hand
Figure 11–18b
Muscles of the Pelvis
and Lower Limbs

Pelvic girdle is tightly bound to axial
skeleton:


permits little movement
has few muscles
Muscles that Position the Lower Limbs
1.
2.
3.
Muscles that move the thigh
Muscles that move the leg
Muscles that move the foot and toes
Muscles that Move the Thigh
Figure 11–19a, b
Muscles that Move the Thigh
Figure 11–19c, d
Muscles that Move the Thigh
Gluteal muscles
 Lateral rotators
 Adductors
 Iliopsoas

Gluteal Muscles (1 of 2)
Cover lateral surfaces of ilia
 Gluteus maximus:

largest, most posterior gluteal muscle
 produces extension and lateral
rotation at hip

Gluteal Muscles (2 of 2)

Tensor fasciae latae:
works with gluteus maximus
 stabilizes iliotibial tract


Gluteus medius and gluteus minimus:
originate anterior to gluteus maximus
 insert on trochanter

Lateral Rotators

Group of 6 muscles, including:
piriformis
 obturator

Adductors

Adductor magnus:


Adductor brevis:


hip flexion and adduction
Pectineus:


hip flexion and adduction
Adductor longus:


produces adduction, extension, and flexion
hip flexion and adduction
Gracilis:

hip flexion and adduction
Muscles that Move the Leg
Figure 11–20a
Muscles that Move the Leg
Figure 11–20b, c
Muscles that Move the Leg

Flexors of the knee:


originate on the pelvic girdle
Extensors of the knee:
originate on the femoral surface
 insert on the patella

Flexors of the Knee
Biceps femoris- Hamstrings
 Semimembranosus- “
 Semitendinosus“
 Sartorius:



originates superior to the acetabulum
Popliteus:

rotates the tibia to unlock the knee
Extensors of the Knee

4 muscles of the quadriceps femoris:
3 vastus muscles
 rectus femoris muscle

Muscles that Move
the Foot and Toes
Figure 11–21a, b
Muscles that Move
the Foot and Toes
Figure 11–21c, d
Muscles that Move
the Foot and Toes

Extrinsic muscles that move the foot
and toes include:
muscles that produce extension at the
ankle
 muscles that produce flexion at the
ankle
 muscles that produce extension at the
toes
 muscles that produce flexion at the
toes

4 Muscles that Produce
Extension at the Ankle
Gastrocnemius
 Soleus
 Fibularis
 Tibialis posterior
+ The Achilles TendonThe calcaneal tendon (Achilles tendon):


shared by the gastrocnemius and soleus
Muscles that Produce
Flexion at the Ankle

Tibialis anterior:

opposes the gastrocnemius
Muscles that Produce Flexion at the Toes
Flexor digitorum longum
 Flexor hallucis longus:


oppose the extensors
Muscles that Produce
Extension at the Toes
Extensor digitorum longum
 Extensor hallucis longus
 Extensor retinacula:


fibrous sheaths hold tendons of toes
as they cross the ankle
The Intrinsic Muscles of the
Foot
Figure 11–22a
The Intrinsic Muscles of the
Foot
Figure 11–22b, c
Effects of Aging
on the Muscular System
1.
2.
Skeletal muscle fibers become
smaller in diameter
Skeletal muscles become less
elastic:

3.
4.
develop increasing amounts of
fibrous tissue (fibrosis)
Decreased tolerance for exercise
Decreased ability to recover from
muscular injuries
Integration with Other
Systems
Figure 11–24