A&P Exam 2

Compact bone

Dense/cortical bone; about 80% of bone mass.

Spongy bone

Cancellous/trabecular bone; about 20% of bone mass.

Hyaline cartilage

Cartilage with no visible fibers.

Elastic cartilage

Cartilage containing elastic fibers.

Fibrocartilage

Cartilage containing collagen fibers.

Support

A bone function that provides a framework for the body.

Protection

A bone function that protects internal organs.

Movement

A bone function that allows muscles to use bones as levers.

Mineral storage

a bone function that stores calcium and phosphate.

Hematopoiesis

Blood cell formation in bone marrow.

Long bone

A bone with a shaft and two ends.

Short bone

A cube-shaped bone.

Sesamoid bone

A bone encased in a tendon; example: patella.

Flat bone

A bone that is thin, flat, and slightly curved.

Irregular bone

A bone with a complicated shape, such as a vertebra.

Osteoprogenitor cell

A stem cell that matures into an osteoblast.

Osteoblast

A bone-forming cell that synthesizes and secretes osteoid.

Osteoid

The initial semisolid organic form of bone matrix.

Osteocyte

A mature bone cell that detects stress and triggers bone formation.

Osteoclast

A large, multinuclear, phagocytic cell that resorbs or breaks down bone matrix.

Bone matrix

The material that makes up bone tissue, including organic and inorganic components.

Hydroxyapatite

Mineral salts, mainly calcium phosphates, that give bone hardness and resistance to compression.

Diaphysis

The shaft of a long bone.

Epiphysis

The end of a long bone.

Metaphysis

The region between the diaphysis and epiphysis.

Medullary cavity

The hollow cavity inside the shaft of a long bone.

Periosteum

The tough outer membrane covering bone.

Endosteum

The membrane lining the internal surfaces of bone.

Articular cartilage

Hyaline cartilage covering the ends of bones at joints.

Epiphyseal plate

A cartilage plate responsible for lengthwise bone growth.

Epiphyseal line

The remnant of the epiphyseal plate after growth ends.

Red bone marrow

Hematopoietic tissue that forms blood cells.

Yellow bone marrow

Fatty marrow formed from red marrow degeneration.

Osteon

The functional unit of compact bone.

Lamellae

Concentric rings of bone matrix surrounding a central canal.

Central canal

A canal containing blood vessels and nerves within an osteon.

Lacuna

A small space containing an osteocyte.

Canaliculi

Small canals that connect osteocytes.

Trabeculae

Rods and plates that form the open lattice of spongy bone.

Osteogenesis/ossification

The process of bone tissue formation.

Intramembranous ossification

Bone formation from a fibrous membrane.

Endochondral ossification

Bone formation by replacing a hyaline cartilage model.

Primary ossification center

The area where bone formation begins in the diaphysis.

Secondary ossification centers

Areas where bone formation occurs in the epiphyses.

Longitudinal growth

Growth that increases the length of a bone.

Appositional growth

Growth that increases the thickness of a bone.

Bone remodeling

The continuous process of bone formation and bone resorption.

Bone deposition

Formation or addition of new bone.

Bone resorption

Breakdown and removal of bone by osteoclasts.

Wolff’s law

Bone grows and remodels in response to the forces placed on it.

Calcitonin

Hormone released when blood calcium rises; stimulates calcium salt deposition in bone

Parathyroid hormone (PTH)

Hormone released when blood calcium falls; stimulates bone breakdown and calcium release.

Axial skeleton

The skull, vertebral column, and rib cage.

Appendicular skeleton

The upper and lower limbs, shoulder girdle, and hip girdle.

Intervertebral disc

A structure between vertebrae that helps connect and cushion them.

Kyphosis

An abnormal curvature of the top of the spine (hunchback).

Lordosis

An abnormal curvature of the spine with excessive inward curvature (swayback).

Scoliosis

An abnormal lateral curvature of the spine.

Ischial tuberosity

The “sit bones” of the pelvis.

Fracture

A break in a bone.

Partial/incomplete fracture

A fracture in which the bone is not completely broken through.

Complete fracture

A fracture in which the bone is completely broken.

Simple/closed fracture

A fracture in which the bone does not penetrate the skin.

Compound/open fracture

A fracture in which the bone penetrates the skin.

Nondisplaced fracture

A fracture in which the bone ends remain aligned.

Displaced fracture

A fracture in which the bone ends are out of alignment.

Transverse fracture

A fracture that runs across the long axis of the bone.

Linear fracture

A fracture that runs parallel to the long axis of the bone.

Oblique fracture

A fracture that runs diagonally across the bone.

Comminuted fracture

A fracture in which the bone breaks into multiple pieces.

Spiral fracture

A fracture caused by a twisting force.

Impacted fracture

A fracture in which broken bone ends are driven into each other.

Greenstick fracture

An incomplete fracture.

Compression fracture

A fracture caused by crushing of the bone.

Depression fracture

A fracture in which bone is pressed inward.

Epiphyseal fracture

A fracture involving the epiphyseal region.

Colles fracture

A fracture of the distal radius.

Pott’s fracture

A fracture involving the ankle region.

Reduction

Realignment of a fractured bone.

Closed reduction

Realignment of a fracture without surgery.

Open reduction

Surgical realignment of a fracture.

Internal fixation

Stabilization of a fracture using hardware inside the body.

External fixation

Stabilization of a fracture using hardware outside the body.

Hematoma

A collection of blood that forms after a fracture.

Soft callus

Early repair tissue formed during fracture healing.

Bony callus

Spongy bone formed during fracture healing.

Osteoporosis

A disorder involving loss of bone mass and increased fracture risk.

Rickets

A disorder involving impaired mineralization of growing bones.

Paget disease

A disorder involving abnormal bone remodeling.

Osteomyelitis

An infection of bone.

Fibrodysplasia ossificans progressiva (FOP)

A disorder involving abnormal bone formation in soft tissues.

Joint/articulation

The location where two bones meet.

Synarthrosis

An immovable joint.

Amphiarthrosis

A slightly movable joint.

Diarthrosis

A freely movable joint.

Fibrous joint

A joint in which bones are connected by dense fibrous connective tissue with no joint cavity.

Cartilaginous joint

A joint in which bones are connected by cartilage with no joint cavity.

Synovial joint

A joint in which bones are connected by ligaments, fluids or capsules with a joint cavity.

Suture

A rigid, interlocking fibrous joint of the skull.

Syndesmosis

A joint in which bones are connected by ligaments or bands of fibrous tissue.