Bones: Structure, Function and Movement
Your skeleton does much more than just hold you up! Bones protect vital organs like your brain and heart, while providing attachment points for muscles via tendons. They form joints (connected by ligaments) that allow both fine and gross movements as they act as levers for your body.
Bones aren't just structural - they're living tissue! They store important minerals like calcium and phosphorus to maintain strength. Inside, bone marrow produces both red blood cells (for oxygen transport) and white blood cells (for fighting infections), increasing production when your body needs them.
The skeleton features different bone types, each with specific purposes. Long bones like the femur generate strength and speed, working as levers. Short bones (carpals in wrists) spread weight loads, while flat bones (skull, ribs) offer protection, and irregular bones (vertebrae) provide both protection and muscle attachment.
Quick Tip: Remember the main movements at joints with this trick - Flexion decreases angles (like bending your arm), Extension increases angles (straightening your arm), Abduction moves away from center (think "aliens abduct"), and Adduction moves toward center.
Your joints enable different types of movement depending on their structure. Ball and socket joints (like your hip) allow the most freedom, while hinge joints (like your elbow) permit movement in one plane. The human skeleton contains 206 bones, from the tiny bones in your ear to the large femur in your thigh.



