Musculoskeletal System
Musculoskeletal System
• 1. Bones (oste/o=bone)- provides the
framework around which the body is
constructed and protect and support internal
organs
• 2. Joints (arthr/o; articul/o= joint)- places at
which bones come together
• 3. Muscles (my/o; myos/o=muscle)- attached
to bones, or to internal organs and blood
vessels. They are responsible for movement
Terms
• -Orthopedic- (orth/o= straight; ped/i= child);
physicians who treat bone & joint disease
• -Rheumatologist- (rheumat/o= watery flow); one who
specializes in the study of joint diseases (because
joint diseases are marked by collection of fluid in joint
spaces
• Chiropractor- (chir/o= hand)- use physical means to
manipulate the spinal column
• -Osteopathy- (oste/o=bone; path= disease)- p/t to
diseases of the bone
– Osteopathic physicians (DO)
Bones
• -Complete organs composed of connective tissue
called osseous (bony) tissue ; plus a rich supply of
blood vessels and nerves
• Osseous tissue consists of osteocytes (bone cells),
collagen (dense connective tissue), and calcium salts
• Ossification- bone formation; “to harden”
• Osteoblasts- immature osteocytes that produce bony
tissue that replaces cartilage during ossification
• Osteoclasts- (-clast=to break); large cells that function
to reabsorb, digest bony tissue. They enlarge the
inner bone cavity so bones do not become too heavy
• *Calcium and Phosphorus are minerals necessary to
produce enzymes to give bones strength
Structure of bones
• 206 bones in the body
• Long bones- found in thigh, lower leg, and upper and
lower arm; strong and broad at end where they join
other bones. They have large surface areas for
muscle attachment.
• Short bones- found in wrist and ankle and are small
with irregular shapes
• Flat bones- cover soft body parts
• Sesamoid bones- small, round and resembles a
sesame seed in shape. They are found near joint.
• Irregular shaped bones- odd shaped (vertebrae)
• What is the largest sesamoid bone in the body?
____________________
Structure of bones
• Diaphysis- (dia-=through/complete; -physis-to grow)
shaft or middle region of a long bone
• Epiphysis- (epi-=above,upon; -physis= to grown) end
of the long bones
• Metaphysis- (meta-=change/beyond) flared portion of
the bone
• Periosteum- (peri-=surround; oste/o=bone) strong,
fibrous, vascular membrane that covers the surface of
long bones
• Articular cartilage- where the ends of long bones and
the surface of any bone meet
• *the bones of a fetus are mostly made of cartilage
Structure of bones
• Compact bone- layer of hard, dense bone
that lies under the periosteum near the
diaphysis of long bones
• Haversian canal- small canals containing
blood vessels that bring O2 and nutrients;
remove waste products (CO2)
• Cancellous bone- “spongy or trabecular”;
porous and less dense than compact bone;
red bone marrow is located here
– Trabeculae- spongy latticework
Bone Processes
• Bone processes are enlarged areas to serve as
attachment for muscles and tendons
• Bone head- rounded end of a bone separated from
the body of the bone by a neck
• Greater Trochanter- large process on the femur for
attachment of tendons and muscle (lesser trochanter
is just smaller)
• Condyle- rounded, knuckle-like process at a joint
• Tubercle- rounded process on many bones for
attachment of tendons and muscles
– Tuberocity- small rounded elevation on a bone
Bone openings or hollow regions
• Fossa- shallow cavity in or on a bone
• Foramen- opening for blood vessels and
nerves
• Fissure- narrow, deep, slit-like opening
• Sinus- hollow cavity within a bone
A) Divisions of a long bone and interior bone structure.
B) Composition of compact (cortical) bone.
Fig. 15-1AB.
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A) Divisions of a long bone and interior bone structure.
B) composition of compact (cortical) bone.
Fig. 15-1AB.
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Bone processes on the femur and humerus.
Fig. 15-2AB.
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Axial vs. Appendicular Skeleton
• Axial- 80 bones
–
–
–
–
–
Skull & face =22
Ear= 6
Thoracic cage (ribs/sternum)= 25
Vertebral column= 26
Hyoid= 1
• Appendicular Skeleton- 126 bones
– Pectoral Girdle= 4
– Upper Extremities= 60
– Pelvic Girdle= 2
– Lower Extremities= 60
TOTAL # of Bones in the body = 206
Cranial bones (lateral view).
Fig. 15-3.
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Cranial bones (looking downward at floor of cranial cavity).
Fig. 15-4.
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Facial bones.
Fig. 15-5.
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Sinuses of the skull.
Fig. 15-6.
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Ear bones & Hyoid bone
Vertebral column.
Fig. 15-7.
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Bones of the Thorax (chest cavity)
• Clavicle
• Scapula
• Sternum
• Ribs
• Acromion
Bones of the Arm and Hand
• Humerus
– Olecranon
•
•
•
•
•
Ulna
Radius
Carpals
Metacarpals
Phalanges
Pelvic Bones
• Pelvic girdle – pelvis;
collection of bones
composed of:
ilium
ischium
pubis
*Pubic SymphysisAnterior part of pelvis
where cartilage
connects
Bones of the Leg and Foot
• Femur
• Patella
• Tibia (medial)
-Malleous
• Fibula (lateral)
• Tarsals -(7 bones)*calcaneus- heel bone is the
largest and sits on talus
• Metatarsals
• Phalanges of the toes
Bones of the foot.
A
B
Fig. 15-11AB.
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Bones of the thorax, pelvis, and extremities.
Fig. 15-9.
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Bones of the thorax, pelvis, and extremities.
Fig. 15-9.
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Fractures- break in a bone
• Closed fx – bone is broken but no open wound
• Open fx- bone is broken and a fragment of bone
protrudes through skin
• Crepitus- crackling sound when ends of bones rub
each other or roughened cartilage
• Colles fx- occurs near the wrist joint at lower end of
radius
• Comminuted fx- bone splintered or crushed into
several pieces
• Compression fx- bone is compressed
• Greenstick fx- bone is partially broken; typically
occurs in children
• Impacted fx- one fragment is driven firmly into another
Open fracture
Colles Fracture
Thumb fracture
Comminuted Fracture
Types of fractures.
Fig. 15-13.
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Pathologic conditions
• Ewing Sarcoma- malignant bone tumor
• Exostosis- bony growth arising from the surface of bone (ex=out;
-ostosis= bone condition)
• Osteogenic sarcoma- (-genic= produced by); malignant tumor
arising from bone (osteosarcoma)
• Osteomalacia- (-malcia=softening) softening of bone (loss of
calcium)
• Osteomyelitis- (myel/o= spinal cord; bone marrow); inflammation
of bone & bone marrow due to infection
• Osteoporosis- (-porosis= condition of pores (space); decrease in
bone density (mass); thinning of bone
• Osteopenia- (-penia= deficieny); interior of bones is diminished
in structure
• Osteodystrophy- (dys- bad, painful, difficult, abnormal) (-trophynourishment or development); poor formation of bone
Pathological Conditions
• Talipes- congenital abnormality in hindfoot
(involving talus; clubfoot)
• Kyphosis- “hunchback”; spine curvature in
thoracic cavity
• Lordosis- lumbar spine curves outward
• Scoliosis- lateral curvature of spine
• Sciatica- pain radiating down the leg
(nerve)
Scanning electromicrograph
(A: Normal bone; B: Bone with osteoporosis).
(From Dempster DW, Shane E, Horbert W, et al: A simple method for correlative light and
scanning electron microscopy of human iliac crest bone biopsies: qualitative observations in
normal and osteoporotic subjects. J Bone Miner Res, 1986; 1:15.)
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Fig. 15-15AB.
Forward
Types of joints
• Joint (arthr/o)- a coming together of two or
more bones
• Suture joint- immovable joint
• Synovial joint- freely moveable
• Joint capsule- bones in a synovial joint
composed of fibrous tissue
• Ligaments- connect bone to bone; thick
fibrous band of connective tissue
– Sprain - trauma to a joint with pain, swelling
and injury to ligaments
• Articular Cartilage- covers the smooth end of
the joints surface
Synovial Joints
Types of Joints
• Synovial Membrane- lies under the joint
capsule and lines the synovial cavity
between the bones.
- The synovial fluid contains water and nutrients
that lubricate the joint.
- Bursae (bursa)-sac that contains synovial fluid
that are located near but not within a joint
- Tendons -connective tissue that connects
muscle to bone
- Tenorrhaphy- suture of a tendon
The knee (A: Sagittal; B: Frontal).
A
B
Fig. 15-18AB.
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Pathological conditions
• Arthritis- inflammation of a joint
– Ankylosing Spondylitis- (ankyl/o= stiff;
spondyl/o=spine or vertebrae) chronic, progressive
arthritis with stiffening of spinal joints/pelvis
– Gouty Arthritis -inflammation and painful swelling of
joints caused by excessive uric acid in the body
(hyperuricemia); typically affects the big toe and is
often called “podagra”
– Osteoarthritis -(OA); progressive, degenerative joint
disease characterized by loss of articular cartilage
and hypertrophy of bone
Osteoarthritis and rheumatoid arthritis.
Fig. 15-19.
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Pathological Conditions
• Rheumatoid Arthritis (RA)- Chronic disease in which
joints become inflamed and painful. It is thought to be
an autoimmune reaction against joint tissues
– Pyrexia (fever) – symptom of RA
• Ankylosis - condition of stiff, bent joint
• Bunion - abnormal swelling of the medial aspect of
the joint between the big toe and first metatarsal
• Carpal Tunnel Syndrome-compression of the median
nerve as is passes between the ligament, bones and
tendons of the wrist.
• Arthroplasty- surgical repair of a joint
• Spondyloliasthesis- slipping or subluxation of
vertebrae
Spondylolisthesis
Carpal tunnel syndrome.
Fig. 15-20AB.
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Pathological Conditions
• Herniation of an intervertebral disk- abnormal
protrusion of a fibrocartilaginous
intervertebral disc into the spinal nerves
• Ganglion cyst- A fluid-filled cyst arising from
the joint capsule or a tendon
Injury to a Joint:
• Dislocation -Displacement of a
bone from its joint
– Reduction= restoration of bones to normal position
– Subluxation= partial dislocation
Elbow Dislocation
Knee Dislocations
Ankle dislocation and fx
Pathological Conditions
• Lyme Disease- a recurrent disorder marked
by severe arthritis, myalgia, malaise, and
neurologic and cardiac syndromes
• Sytemic Lupus Erythematosus (SLE)chronic inflammatory autoimmune disease
involving joints, skin, kidneys, nervous
system, heart and lungs;
characterized by ‘butterfly rash”
Protrusion of an intervertebral disc.
*Laminectomy- operation to relieve symptoms of a
slipped disk
Fig. 15-22.
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Muscles
Muscles
• Cardiac muscle- striated in appearance but is like
smooth muscle in action; no conscious controlled;
• Smooth muscle- involuntary or visceral muscle that
move internal organs. They have no dark or light
bands, fibrils, or cytoplasm
• Leiomyosarcoma- malignant tumor of smooth muscle
• Striated muscle- voluntary or skeletal muscle that
move all bones
– Fascia- fibrous tissue that envelops and separates
muscles and contains the blood, lymph, and nerves
Uterine leiomyosarcoma
Cardiac Tissue
Smooth Tissue
Striated Tissue
Muscles
• Skeletal muscle- over 600 in the human
body.
• The point of attachment of the muscle to a
stationary bone is called origin (beginning).
• When the muscle contracts, another bone to
which it is attached to does move. The point
of junction of the muscle to the bone that does
move is called the insertion of the muscle.
• *Most often, the origin of a muscle lies proximal in the
skeleton and insertion lies distal.
• Atrophy- wasting away of muscle (shrinking of size)
a= no, not, or without; trophy= process of development/ nourishment
Origin and insertion of the biceps.
Fig. 15-26.
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Major Muscles
Terms for muscle/joint movement
•
•
•
•
Abduction- movement away from midline
Adduction- movement toward the midline
Dorsiflexion- backward (upward) bending of the foot
Plantarflexion- bending the sole of foot downward to
ground
•
•
•
•
•
Extension- straightening of flexed limb
Flexion- bending a joint
Supination- turning the palm forward
Pronation- turning the palm backward
Rotation- circular movement around a central point
Types of muscular actions.
Fig. 15-27.
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Abbreviations
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•
•
•
•
•
•
•
•
•
•
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ROM- range of motion
ACL- anterior cruciate ligament
PCL- posterior cruciate ligament
MCL- medial collateral ligament
LCL- lateral collateral ligament
EMG- electromyography
RA- rheumatoid arthritis
PT- physical therapy
NSAID- nonsteriodal anti-inflammatory drug
TMJ- temporomandibular joint
THR- total hip replacement
TKR- total knee replacement