Skeletal System: Anatomy, Diseases, and Medical Procedures

Ossification

Begins after 3-months gestation and continues through adolescence.

Osteoclasts

Carry off old or damaged bone.

Osteoblasts

Build the bones back up.

Periosteum

Tough, fibrous tissue forming outermost covering of bone.

Compact bone

Dense, hard strong bone forming protective outer layers of bone.

Spongy bone

Porous, thus more susceptible to fractures.

Red Bone Marrow

Located inside the ends of long bones and certain short bones.

Medullary cavity

Center of long bones; storage site of red and yellow bone marrow.

Endosteum

Lines medullary cavity.

Yellow bone marrow

Fat storage in long bone medullary cavity.

Cartilage

Smooth, rubbery connective tissue acting as shock absorber.

Articular cartilage

Covers surface of articulations (joints) allowing smooth joint movement.

Meniscus

Curved fibrous cartilage in some joints.

Diaphysis

Shaft of long bones.

Epiphysis

Wider ends of long bones.

Foramen

Opening in a bone allowing passage of blood vessels, nerves, and ligaments.

Process

Projection allowing for the attachment of muscles or tendons.

Fibrous Joints

Inflexible layers of dense connective tissue that hold bones tightly together.

Cartilaginous Joints

Consist of bones connected by cartilage allowing slight movement.

Synovial Joints

Articulation of joints permitting variety of movements.

Synovial capsule

Outermost layer, resembling a sleeve.

Synovial membrane

Lines capsule and secretes synovial fluid.

Ligaments

Fibrous tissues connecting one bone to another bone.

Bursae

Fibrous sac acting as cushion, easing movement in areas subject to friction.

Axial Skeleton

Consists of the bones of the head, chest, and back.

Appendicular Skeleton

Consists of the bones of the shoulders, arms, hips, and legs.

Cranium

8 bones.

Face

14 bones.

Middle ear

6 bones.

Auditory Ossicles

Three tiny bones located in each middle ear: Malleus, Incus, Stapes.

Fontanelles

Also known as 'Soft Spots', allow cranial bones to move together during birth and grow apart as the brain grows.

Thoracic Cavity

The chest contains the Rib Cage

Rib Cage

12 pairs of ribs

True ribs

Ribs 1-7

False ribs

Ribs 8-10

Floating ribs

Ribs 11-12

Combing Form

cost/o = rib

Sternum

Flat bone located in middle of the chest

Manubrium

Forms upper portion of the sternum

Body (sternum)

Forms middle portion of the sternum

Xiphoid process

Made of cartilage; forms lower portion of the sternum

Clavicle

Collar bone; connects manubrium to scapula

Scapula

Shoulder bone

Acromion

Extension of scapula; forms high point of the shoulder

Humerus

Upper arm

Radius

Smaller, shorter bone in forearm

Ulna

Larger, longer bone of forearm

Carpal bones

Eight bones that form the wrist

Metacarpal bones

Five bones that form the palms of the hand

Phalanges

Fourteen bones of the fingers

Cervical vertebrae

Set of seven (C1-C7); form the neck

Thoracic vertebrae

Set of 12 (T1-T12); a pair of ribs attached to each

Lumbar vertebrae

Set of five (L1-L5); largest and strongest vertebrae

Sacrum

Forms lower portion of the back; five separate bones at birth that fuse together

Coccyx

Known as tailbone; forms end of the spine

Ilium

Forms back and sides of pubic bone

Ischium

Forms lower posterior portion of pubic bone

Pubis

Forms anterior portion of pubic bone

Pubic symphysis

Cartilaginous joint uniting left and right pubic bones

Acetabulum

Large circular cavity in each side of the pelvis; articulates with head of femur to form hip joint

Femur

Largest bones in the body

Patella

Kneecap

Tibia

Shinbone; larger anterior weight-bearing bone of lower leg

Fibula

Smaller of the two bones of lower leg

Talus

Articulates with tibia and fibula

Calcaneus

Heel bone; largest of tarsal bones

Metatarsals

Five bones that form part of the foot to which toes are attached

Hallux valgus

Abnormal enlargement of joint at the base of the great toe; also known as a bunion

Osteoarthritis

Most commonly associated with aging; characterized by wearing away of articular cartilage within joints

Gout

Type of arthritis characterized by deposits of uric acid crystals in joints, usually beginning with the big toe

Rheumatoid Arthritis

Chronic autoimmune disorder attacking joints and other organs

Herniated Disk

Breaking apart of intervertebral disk resulting in pressure on spinal nerve roots

Osteoporosis

Marked loss of bone density with increase in bone porosity; frequently associated with aging

Multiple Myeloma

Cancer occurring in blood-making cells found in red bone marrow

Osteoporosis-Related Fractures

Fractures associated with weakened bone due to osteoporosis.

Compression fracture

Compression of bone on itself.

Colles' fracture

Fracture at lower end of radius.

Osteoporotic hip fracture

Broken hip due to osteoporosis; may occur spontaneously or as a result of a fall.

Closed fracture

Bone is broken; no open wound in skin.

Open fracture

Bone is broken; open wound in the skin.

Transverse fracture

Occurs straight across the bone.

Oblique fracture

Fracture is at an angle across the bone.

Comminuted fracture

Bone is splintered.

Greenstick fracture

Bone is bent and partially broken; seen frequently in children.

Pathologic fracture

Due to weakened bone; not due to trauma.

Spiral fracture

Due to twisting action.

Stress fracture

Due to overuse.

Fat embolus

May form with fracture of long bone; fat cells from yellow bone marrow are released into the blood.

Crepitation

Grating sound when ends of broken bone move together.

Callus

Bulging deposit around the area of the break; tissue eventually becomes bone.

Bone Density Testing

Screening test for osteoporosis or other conditions related to loss of bone mass.

Orthotic

Mechanical appliance designed to control, correct, or compensate for impaired limb function.

Prosthesis

Substitute for a diseased or missing body part.

Arthrodesis

Surgical fusion of two bones.

Arthroscopic surgery

Minimally invasive procedure for treating interior of joint.

Chondroplasty

Surgical repair of damaged cartilage.

Total knee replacement

All parts of the knee are replaced.

Partial knee replacement

Only part of the knee is replaced.

Total hip replacement

Restores damaged hip to full function.

Hip resurfacing

Placing of metal cap over head of femur to restore function of the hip.