Skeletal System
General Info
• Organs called bones
• Adult human has 206
bones
Functions of Bones
• Framework
– Supports muscle, fat and skin
• Protection
– Surrounds vital organs
– EX: skull, ribs, pelvis
• Levers
– Muscles attach to bones to provide movement
• Production of blood cells
– Red and white blood cells and platelets
• Storage
– Calcium
Bone Anatomy
• Long Bones
Shaft – diaphysis
2 ends – epiphysis
Layers
Periosteum
Medullary canal
red marrow
yellow marrow
Endosteum
Skeleton Sections
• Axial
– Main Trunk
• Composed of skull, spinal column, ribs and
breastbone
• Appendicular
– Extremities
• Shoulder girdle, arm bones, pelvic girdle, leg
bones
Bones of the Body
• Skull
Fontanels
Soft Spots – allow the skull to
enlarge as the brain grows
Sinuses
• Air spaces in the
bones
• Act as resonating
chambers for the
voice
• Lined with mucous
membranes
Ribs
• 12 Pairs
• True ribs
– First 7 pairs
– Attach to thoracic
vertebrae and sternum
• False ribs
– Next 5 pairs
– Attach to the cartilage of
the ribs above
– Floating ribs
• Last 2 pairs of false ribs
• Have no attachment in
the front
Sternum
• Three parts
– Manubrium
– Body
– Xiphoid process
Spinal Column
• 26 Vertebrae
Spinal Section Reference
• Cervical
– C1 to C7
• Thoracic
– T1 to T 12
• Lumbar
– L1 to L5
• Sacral
• Coccyx
Shoulder Girdle
• Each side composed of
– 1 clavicle
– 1 scapula
Arm Bones
• Humerus
– Upper arm bone
• Ulna
– Lower arm bone
• Radius
– Lower arm bone
– On thumb side
Wrist, Hand and Fingers
• Wrist
– 8 carpals
• Hand
– 5 Metacarpals
– Palm of the hand
• Fingers
– 14 Phalanges
Pelvic Girdle
• Composed of 2 os coxae
• Ilium, ischium and the pubis
Upper Leg Bones
• Femur
– Largest bone in
the body
Lower Leg Bones
• Tibia
– Large lower leg bone
• Fibula
– Small lower leg bone
• Patella
– Knee cap
Ankle, Foot and Toes
• Tarsals
– 7 bones
– Ankle
• Metatarsals
– 5 bones
– Instep
• Phalanges
– 14 bones
– Toes
• Calcaneous
– Heel bone
Joints
• Area where 2 or more
bones come together
• Held together by
ligaments
• Types
–
–
–
–
–
–
–
Ball and socket
Hinge
Slightly movable
Immovable
Pivot
Gliding
Saddle
Types of Joints
Diseases
• Arthritis
– Inflammation of the
joint
– Types
• Osteoarthritis
• Rheumatoid
– Terms
• Acute
• Chronic
Fracture
• Greenstick
– Common in children
– Bone bent and splits
Simple and Compound Fractures
• Simple
– Clean break in the
bone
• Compound
– Bone breaks and
pierces skin
Spiral Fracture
Impacted Fracture
Comminuted Fracture
Depressed Fracture
Treatment of Fractures
• Reduction
– Closed
Open Reduction
Bone Repair
Dislocation
• A bone is forcibly displaced from a joint
Sprain
Twisting action tears ligaments
Osteoporosis
Softening of bone due to lack of
calcium
Curvatures of the Spine
• Scoliosis
side-to-side, lateral
curve
Lordosis
• Swayback
• Abnormal inward
curve of the lumbar
region
Kyphosis
• Hunchback
• Rounding or bowing
of the back of the
thoracic area
Vocabulary
arthro- joint
chondro- cartilage
cost- rib
crani- skull
carpwrist
myelo- bone marrow, spinal cord
osse-, ossi-, oste-, osteo - bone
-ectomy surgical removal of
-otomy to cut into
-osis condition
Skeleton Jokes
Why doesn't a skeleton play music in a church?
He has no organ
What does a skeleton order at a restaurant?
Spare Ribs
The End