The Skeletal System: Bone Structure, Joints, and Cartilage in Veterinary Anatomy

Bones

Structures that provide support, protection for vital organs, and store minerals.

Cartilage

Tough, somewhat flexible connective tissue found in ears, nose, vocal cords, and trachea.

Ligaments

Strips of tough, fibrous connective tissue that connect bones and cartilages.

Hematopoiesis

Formation of blood cells.

Matrix

Mineralized calcium (CA) and phosphorus (P) that gives bones their strength.

Periosteum

Membrane that contains nerves and blood vessels supplied to the bone.

Osteocytes

Bone cells.

Osteoblasts

Bone forming cells.

Osteoclasts

Bone eating cells.

Endoskeleton

Skeletal structure located beneath the skin.

Exoskeleton

Skeletal structure located on the outside of the animal.

Compact or cortical bone

Outer part of bone that is very strong and hard.

Cancellous or spongy bone

Not dense bone with spicules, involved in bone marrow storage.

Bone Marrow

Tissue that produces red blood cells (RBC) and stores fat cells.

Bone Shapes

Categories of bones including long, short, irregular.

Epiphysis

Located at the ends of the bone, sits upon the epiphyseal plate.

Diaphysis

Shaft of the bone located between epiphyseal plates.

Metaphysis

Widest part of the diaphysis, immediately next to the epiphyseal plates.

Axial Skeleton

Part of the skeleton that includes the head and trunk.

Appendicular Skeleton

Part of the skeleton that includes leg bones.

Visceral Skeleton

Skeleton embedded in soft organs.

Synovial Joints

Joints that allow full movement and can move freely in six directions.

Flexion

Decreases the angle between two bones.

Extension

Increases the angle between two bones.

Abduction

Moves a limb away from the median plane.

Adduction

Moves a limb toward the median plane.

Rotation

Twists a bone on its own axis.

Circumduction

Moves the distal end of an appendage in a circle.

Chondrocytes

Cells that make up cartilage.

Perichondrium

Thin covering membrane over cartilage.

Hyaline Cartilage

Most common type of cartilage, composed of collagen fibers.

Elastic Cartilage

Similar to hyaline but with elastic fibers for flexibility.

Fibrocartilage

Very tough cartilage with more collagen, found in intervertebral disks.

Tendons

Connect muscles to bones.