Content

• How many soft bones are we born with?


  About 300
• What happens to cartilage during childhood and adolescence?


  It grows and is slowly replaced by hard bone
• How many bones are in the adult skeleton?


  206 bones
• What is bone primarily made of?

  A mixture of flexible collagen fibers and mineral salts like calcium phosphate
• What are bones classified as?


  Living, growing, and developing organs
• What do bones require for their function?

  Oxygen and nutrients
• What system provides support and movement in the body?


  The musculoskeletal system
• What percentage of the body's calcium is contained in bones?


  99%
• What do bones produce?

  Red blood cells
• How strong are bones compared to steel?


  Bones are as strong as steel
• How often does the skeleton replace parts of itself?


  Every 7-10 years
• What are the four main types of bone?

  • Long bone: Arm and leg bones
  • Short bone: Wrist and ankle bones
  • Flat bone: Ribs, shoulder blades, breast bone, skull
  • Irregular bone: Vertebrae
• What are the two types of bone tissue?

  • Compact bone: Hard outer layer, strong and dense
  • Spongy bone: Lighter, less dense, found in ends of long bones
• What is compact bone also known as?

  Cortical bone
• What are Haversians in compact bone?


  Cylinders that form the structure of compact bone
• What runs through the Haversian canal?


  Blood vessels and nerves
• What are lamellae in bone structure?


  Layers of hard bone that surround the Haversian canal
• What do lacunae contain?


  Living osteocytes (bone cells)
• What are canaliculi in bone?


  Tiny channels found in bone for nutrition
• Where does spongy bone lie?


  It lies beneath most compact bone
• How does spongy bone appear?


  It looks like a honeycomb or sponge
• What are trabeculae in spongy bone?


  Thin columns and plates of bone that create a spongy structure
• Where is cancellous bone located?


  At the ends of long bones and in the pelvis, ribs, skull, and vertebrae