Chapter 5: Skeletal System Vocabulary

Comprehensive vocabulary flashcards generated from lecture study notes on Chapter 5: Skeletal System.

Axial skeleton

Bones that form the longitudinal axis of the body, including the skull, spine, and ribs.

Appendicular skeleton

Bones of the limbs and girdles.

Hematopoiesis

The process of blood cell formation that occurs within bones.

Compact bone

Dense, hard bone tissue that provides strength and protection.

Spongy bone

Porous bone tissue found on the ends of bones that provides flexibility.

Long bones

Bones that are longer than they are wide, composed mostly of compact bone.

Short bones

Cube-shaped bones containing mostly spongy bone.

Flat bones

Thin, flattened, and usually curved bones.

Irregular bones

Bones with complex shapes that do not fit other structural categories, such as vertebrae and hip bones.

Diaphysis

The shaft of a long bone.

Periosteum

The protective membrane surrounding the diaphysis of a long bone.

Epiphyses

The ends of long bones.

Articular cartilage

Hyaline cartilage tissue covering the ends of bones at joints.

Epiphyseal plate

Hyaline cartilage layer in growing bone that initiates bone growth.

Epiphyseal line

The remnant of the epiphyseal plate in adult bone.

Medullary cavity

Cavity inside the shaft of a long bone containing yellow marrow in adults and red marrow in children.

Osteoblast

A bone-building cell that takes calcium from the blood and stores it in bone tissue.

Osteocyte

A mature bone cell situated within the lacunae.

Osteoclast

A bone-breaking or resorbing cell that breaks down bone matrix to release calcium into the blood.

Osteon

The structural unit of compact bone.

Central (Haversian) canal

The central canal of an osteon carrying blood vessels and channels.

Lamellae

Concentric rings of bone matrix within an osteon.

Lacunae

Small spaces within the bone matrix that contain osteocytes.

Canaliculi

Tiny channels connecting lacunae that allow communication between bone cells.

Parathyroid hormone (PTH)

Hormone released when blood calcium is low, stimulating osteoclast activity to break down bone and release calcium into the blood.

Calcitonin

Hormone released when blood calcium is high, stimulating osteoblast activity to take calcium from the blood and store it in bone.

Rickets

A disease in children where bones fail to calcify, usually caused by a lack of calcium or vitamin D in the diet.

Simple (closed) fracture

A bone fracture where the bone breaks cleanly without protruding through the skin.

Compound (open) fracture

A fracture where broken ends of bone protrude through the skin, creating a risk of bone infection.

Comminuted fracture

A fracture where the bone breaks into many pieces.

Compression fracture

A fracture where the bone is crushed, typical in osteoporotic bones.

Depression fracture

A fracture where the broken bone is pressed inward, typical of skull fractures.

Impacted fracture

A fracture where broken bone ends are forced into each other.

Spiral fracture

A ragged bone break occurring when excessive twisting forces are applied to a bone, common in sports.

Greenstick fracture

An incomplete bone break common in children who have more collagen in their matrix than adults.

Synarthroses

Immovable joints, such as skull sutures.

Amphiarthroses

Slightly movable joints, such as those found between ribs and vertebrae.

Diarthroses

Freely movable joints, such as those in limbs.

Fibrous joints

Joints connected by fibrous tissue.

Cartilaginous joints

Joints where bone ends are connected by cartilage.

Synovial joints

Joints where articulating bone ends are separated by a joint cavity containing synovial fluid.

Bursitis

Inflammation of a bursa or synovial membrane associated with a joint.

Sprain

Injury in which ligaments or tendons are damaged by excessive stretching or torn from the bone.

Osteoarthritis

A chronic condition common in older people characterized by the breakdown of articular cartilage.

Rheumatoid arthritis

A chronic autoimmune inflammatory disorder that symmetrically affects joints such as fingers, wrists, ankles, and feet.

Gouty arthritis (gout)

Joint disorder caused by excess uric acid in blood depositing needle-shaped crystals in joint soft tissue, typically affecting a single joint like the great toe.

Osteoporosis

A condition involving loss of bone mass leading to thin, fragile bones, particularly affecting vertebrae and the neck of the femur.

Bone remodeling rate

The remodeling process occurring approximately every $300\text{ days}$ in males and every $200\text{ days}$ in females.