Transport systems in Bone

Question 1

Compact Bone

Answer 1

Osteon (Haversian system) = is the basic transport unit

• Osteocytes are arranged in concentric lamellae
• Around a central canal containing blood vessels
• Perforating (Volkmann’s) canals
  - Perpendicular to the central canal
  - Carry blood vessels into bone + marrow
• Circumferential Lamellae – bind osteons together

Question 2

Spongy (Cancellous) Bone

Answer 2

• Does not have osteons
• The matrix forms an open network of trabeculae
• Trabeculae themselves have no blood vessels
• The space b/w trabeculae is filled w/ red bone marrow
  
  • Which has blood vessels
  • Forms red blood cells
  • And supplies nutrients to osteocytes

Yellow bone marrow
- some bones contain yellow bone marrow (stores fat)