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 – diaphysis2 ends – epiphysisLayers Periosteum

Medullary canalred marrowyellow

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

FontanelsSoft 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

SprainTwisting action tears ligaments

OsteoporosisSoftening of bone due to lack of

calcium

Curvatures of the Spine

• Scoliosisside-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

Vocabularyarthro- jointchondro- cartilagecost- ribcrani- skullcarp- wristmyelo- bone marrow, spinal cordosse-, 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