Bones Flashcards
What are the functions of bones?
Supports weight.
Protection.
Mineral store.
Blood formation.
What is the function of sesamoid bones?
Redistributes weight to protect tendons from stress, and increases its mechanical effect.
Often a few millimetres in size.
Describe the structure of compact bone.
Organised in circular structures (osteons).
Horizontal perforating Volkmann canals are present.
What are osteons?
Osteocytes and concentric rings of bone matrix surrounding a central Haversian canal.
Describe the structure of spongy bone.
A network of lamellated trabeculae filled with bone marrow. The orientation of trabeculae reflects the main directions of mechanical forces.
No Haversian systems.
What cells are present in bone?
Osteoclasts.
Osteoblasts.
Osteocytes.
What is the bone ECM made of?
Hydroxyapatite crystals - stiff for support, strong under compression.
Type I collagen - gives the bone flexibility, strong under tension.
Water.
What special features does bone have?
A composite material of minerals and collagen.
Can heal themselves of fractures.
Can mechanically adapt as a result of movement.
What are the two types of bone marrow?
Red - forms all blood cells (but not lymphocytes).
Yellow - stores fats. Can be converted into red bone marrow during fever or blood loss.
What is the function of long bones?
Movement of limbs.
How are trunk bones protective?
They vary between long, flat and irregular.
What bones are axial?
Skull, ribs, and vertebral column.
What bones are appendicular?
Clavicle, scapula, hip and limb joints.
What is found in Volkmann’s canals?
Blood vessels.
What are the six types of bone shape?
Long.
Short.
Sutural.
Flat.
Sesamoid.
Irregular.
