Skeleton & Movement

Functions of the Skeleton

• Support: Provides shape and support to the body.
• Protection: Protects vital organs (e.g., skull protects brain).
• Movement: Bones act as levers with muscles to produce movement.
• Blood cell production: Bone marrow produces red and white blood cells.
• Mineral storage: Stores calcium and phosphorus.

Types of Bones

• Long bones: e.g., femur, humerus (support and movement).
• Short bones: e.g., carpals, tarsals (strength and stability).
• Flat bones: e.g., skull, sternum (protection).
• Irregular bones: e.g., vertebrae (protection and support).
• Sesamoid bones: e.g., patella (reduce friction in joints).

Joints and Their Types

A joint is a point a the body where two bones meet.

• Ball and socket: e.g., shoulder, hip (movement in many directions).
• Hinge: e.g., elbow, knee (movement in one plane).
• Pivot: e.g., neck (rotation).
• Gliding: e.g., wrist, ankle (sliding movement).
• Saddle: e.g., thumb joint (flexion, extension, circumduction).
• Immovable: e.g., skull bones (no movement).

Practice Questions

• State five functions of the human skeleton. (5 marks)
• Differentiate between long bones and short bones with examples. (4 marks)
• List three types of joints and give one example each. (3 marks)
• Explain how the skeleton aids movement. (3 marks)
• Short answer: Which bone produces blood cells? (1 mark)