Skeletal System Overview – Key Vocabulary

These vocabulary flashcards cover bone types, internal bone structures, key cells, physiological processes, and common fracture classifications discussed in the lecture.

Carpal Bones

Eight short bones forming the wrist.

Tarsal Bones

Seven short bones forming the ankle.

Sesamoid Bones

Small, round bones embedded in tendons; reduce friction and handle pressure.

Patella

The kneecap; largest sesamoid bone in the body.

Flat Bones

Thin, often curved bones such as cranial bones and scapulae; provide protection and surface area for muscle attachment.

Cranial Bones

Flat bones forming the skull to protect the brain.

Scapulae

Shoulder blades; flat bones important for upper-limb articulation.

Irregular Bones

Complex-shaped bones like the vertebrae that do not fit other categories.

Vertebrae

Series of irregular bones making up the spinal column.

Compact Bone

Dense, hard outer layer of bone providing strength and protection.

Spongy Bone (Cancellous/Trabecular)

Porous inner bone tissue housing bone marrow.

Bone Marrow

Soft tissue inside bones; contains red and yellow varieties.

Red Bone Marrow

Marrow responsible for hematopoiesis—the production of blood cells.

Yellow Bone Marrow

Fat-rich marrow serving as long-term energy storage.

Hematopoiesis

Process of forming red blood cells, white blood cells, and platelets.

Intraosseous Infusion

Emergency delivery of fluids or drugs directly into bone marrow.

Fat Embolism Syndrome

Rare complication where marrow fat enters bloodstream after severe fracture.

Osteoblasts

Bone-building cells that synthesize new bone matrix.

Osteocytes

Mature bone cells maintaining bone tissue.

Osteoclasts

Bone-resorbing cells that dissolve bone using acids and enzymes.

Bone Remodeling

Continuous cycle of bone resorption and formation adapting to stress.

Resorption Pit

Depression created by osteoclasts during bone breakdown.

Osteoid

Unmineralized bone matrix laid down by osteoblasts.

Mineralization

Hardening of osteoid as calcium and phosphate crystallize.

Calcium Homeostasis

Hormonal regulation of blood and bone calcium levels.

Chondroblasts

Cartilage-forming cells that produce cartilage matrix.

Chondrocytes

Mature cartilage cells that maintain cartilage tissue.

Cartilage

Flexible connective tissue cushioning joints and forming bone templates in development.

Fracture Hematoma

Blood clot that forms immediately after bone fracture.

Callus

Cartilage and bone tissue that stabilizes a fracture during healing.

Closed (Simple) Fracture

Bone break that does not penetrate the skin.

Open (Compound) Fracture

Bone break that pierces the skin, increasing infection risk.

Comminuted Fracture

Fracture where bone splinters into three or more pieces.

Impacted (Buckle) Fracture

Fracture where bone ends are driven into each other; common in children.

Greenstick Fracture

Partial fracture where bone bends and cracks but doesn’t break completely; typical in children.