SKELETAL SYSTEM

What is the skeletal system?

The body's framework made up of bones, joints, cartilage, and ligaments.

What are the two main divisions of the skeleton?

Axial skeleton and appendicular skeleton.

Axial skeleton

Forms the central part of the body, including the skull, vertebral column, ribs, and sternum.

Appendicular skeleton

Includes the bones of the limbs and the structures that attach the limbs to the axial skeleton.

Function of the skull

Protects the brain, provides attachment points for muscles, and helps form the structure of the face and head.

Function of the clavicle (collar bone)

Connects the upper limb to the trunk, stabilizes the shoulder, and allows free movement.

What is the main function of the vertebral column?

Supports the head and trunk, protects the spinal cord, allows trunk movement, and provides muscle attachment.

What is a sesamoid bone?

A bone that develops within a tendon, with the main example being the patella (kneecap).

Osteoblasts

Cells that build new bone.

Osteoclasts

Cells that break down old bone tissue.

What is osteoporosis?

A condition where bones become less dense, weaker, and more fragile, increasing fracture risk.

What is a synovial joint?

A freely movable joint that includes major joints like the shoulder, elbow, and knee.

Flexion

Decreases the angle at a joint.

Extension

Increases the angle at a joint.

What do tendons connect?

Muscle to bone.

What do ligaments connect?

Bone to bone.

Cartilage

Smooth connective tissue that helps protect joints and reduce friction.

Function of the ribs

Protect the heart and lungs and help form the thoracic cavity.

Scapula

Also called the shoulder blade; provides attachment for muscles, forms part of the shoulder joint, and allows arm movement.

Kyphosis

An excessive outward curve of the upper spine.

Scoliosis

An abnormal sideways curvature of the spine.

Bone remodeling

The continuous process of breaking down old bone and building new bone.

Epiphyseal plate

Also called the growth plate, it allows long bones to grow in length.

What is the natural curve of the spine?

Curves help absorb shock, distribute body weight, maintain balance, and allow efficient movement.

What is the function of the pelvis?

Supports the trunk, transfers forces between the upper and lower body, and protects pelvic organs.

What are the five types of bone?

Long, short, flat, sesamoid, and irregular.

Articular cartilage function

Reduces friction, absorbs shock, and allows smooth movement at joints.

Synovial fluid function

Reduces friction and nourishes articular cartilage within synovial joints.

What are the three main types of joint?

Fibrous, cartilaginous, and synovial.

What is neutral spine?

The spine is positioned in its natural alignment, not completely straight, allowing proper force distribution and reduced stress.

What is the role of ligaments?

Connect bone to bone, stabilize joints, and limit excessive movement.