The Skeletal System

Key Notes:

Definition of the Skeletal System:

• The skeletal system is the framework of bones that supports and shapes the body.

Functions of the Skeletal System:

• Support: The bones provide structure and support for the body, helping to maintain shape.
• Movement: Bones work with muscles to enable movement.
• Protection: The skeletal system protects vital organs (e.g., the skull protects the brain, and the ribcage protects the heart and lungs).
• Production of Blood Cells: Bones contain bone marrow, which produces red and white blood cells.
• Storage of Minerals: Bones store important minerals like calcium and phosphorus.

Types of Bones:

• Long Bones: Found in arms and legs (e.g., femur, humerus).

• Short Bones: Found in wrists and ankles (e.g., carpals, tarsals).

• Flat Bones: Protect internal organs (e.g., skull, ribs).

• Irregular Bones: Have complex shapes (e.g., vertebrae, jawbone).

Major Parts of the Skeletal System:

• Skull: Protects the brain.

• Spine (Vertebral Column): Consists of vertebrae and supports the body.

• Ribcage: Protects the heart and lungs.

• Limbs: Includes arms and legs, made up of bones like the humerus (upper arm), radius and ulna (forearm), femur (thigh), and tibia and fibula (lower leg).

Joints:

Definition: Joints are places where two or more bones meet.

Types of Joints:

• Hinge Joint: Allows back-and-forth movement (e.g., elbow, knee).

• Ball-and-Socket Joint: Allows movement in many directions (e.g., shoulder, hip).

• Pivot Joint: Allows rotation (e.g., neck).

Cartilage:

• A flexible, rubbery tissue that cushions joints and prevents bones from rubbing together.

Ligaments:

• Strong tissues that connect bones to each other at joints.

Bones and Health:

• Bone Care: Exercise and a diet rich in calcium and vitamin D are important for strong bones.
• Osteoporosis: A condition where bones become weak and brittle due to lack of calcium.

Let’s practice!