Mod 6 Skeletal System

Skeletal System

The organ system composed of bones, cartilages, tendons, and ligaments.

Extracellular Matrix

A complex structure consisting of collagen, ground substance, organic molecules, water, and minerals that defines the characteristics of connective tissues.

Collagen

A tough, ropelike protein that provides strength to connective tissues.

Proteoglycans

Large molecules made of polysaccharides that attract water and contribute to the smoothness and resilience of cartilage.

Hydroxyapatite

Mineral crystals, primarily calcium phosphate, that provide compression strength to bone.

Ossification

The process of bone formation by osteoblasts.

Intramembranous Ossification

The process of bone formation that occurs within connective tissue membranes, mainly in skull bones.

Endochondral Ossification

The process of bone formation that occurs within a cartilage model, where the cartilage is eventually replaced by bone.

Osteoblasts

Cells responsible for the formation of bone and its repair.

Osteoclasts

Cells that break down bone tissue during the process of bone remodeling.

Vertebral Column

The central axis of the skeleton, extending from the base of the skull to the pelvis, composed of 26 vertebrae.

Axial Skeleton

The part of the skeleton that includes the skull, vertebral column, and thoracic cage.

Foramen

A hole in a bone through which blood vessels and nerves can pass.

Condyle

A smooth, rounded end of a bone that articulates in a joint.

Synovial Joint

A type of joint characterized by a fluid-filled joint cavity, allowing for free movement.

Amphiarthrosis

A slightly movable joint.

Diarthrosis

A freely movable joint.

Flexion

The act of bending a joint.

Extension

The act of straightening a joint.

Abduction

Movement away from the midline of the body.

Adduction

Movement toward the midline of the body.

Bone Remodeling

The ongoing replacement of old bone tissue by new bone tissue.

Ligaments

Strong, flexible connective tissues that connect bones to other bones.

Tendons

Tough cords that attach muscles to bones.

Articulating Surfaces

The surfaces of bones that come into contact with one another at joints.

Cartilage

A flexible connective tissue found in various parts of the body, providing cushioning in joints.

Periosteum

A dense layer of vascular connective tissue that envelops the bones.

Spongy Bone

Lightweight bone tissue found at the ends of long bones and in the interior of others.

Compact Bone

Dense bone tissue that forms the outer layer of bones.

Sesamoid Bones

Small bones that develop in tendons, such as the kneecap.

Joint Capsule

A fibrous capsule surrounding a synovial joint, providing stability and structure.