What are the 4 bone classes and give an example of each.
Long - femur, humerus
Short - carpals
Flat - sternum, ribs
Irregular - vertabrae
What are the 2 principle types of connective tissue?
Describe structure and function of compact bone.
Function as levers
Overview the structure and function of cancellous bone.
Constructed of traberculae
Function - weight bearing and shock absorbtion
Describe the structure function of inorganic component in bone matrix.
Hydroxyapatite (mineral salts)
Describe the structure and function of organic component in bone matrix.
Ground substance (proteoglycans)
Resists tension (adds "spring" to bones)
List the 3 principle cell types in bone
Perform endochondral ossification
The bone builders
Involved in remodelling
Breakdown bone matrix
Found in lacunae
Mature osteoblasts (about 20%)
Cytoplasmic processes link to other osteoclasts in bone matrix
Describe an osteon and it's parts
Functional unit of compact bone responsible for maintenance
Consists of blood vessel in central canal surrounded by concentric bone layers called lamallae
Blood vessels feed osteocytes in lacunae via their cytoplasmic processes running through canaliculi.
Name two sites of bone growth
Diaphysis - primary centre
Epiphysis - secondary centre
Describe how bones grow in length.
Bone grows for the diaphysis against the growth plate, an area of inactive cartilage between the diaphysis and epiphyses. This allows bone to grow in length at end of diaphysis without reaching the epiphyses and joining it.
Joining of the epiphyses and diaphysis only occurs when bone has reached it's full size
Describe how bones grow in width.
Osteoblasts in the sub-periosteal layer ossify bone, building outwards.
Osteoclasts remodel the bone on the inside, maintaining bone thickness and the medullary cavity.
Describe how the structure of cancellous bone relates to its function.
Cancellous bone consists of highly ordered traberculae which are arranged to best cope with stresses on the bone through weight and activity
List the 5 functions of the skeletal system.
How many bones comprise the axial skeleton?
How many bones in the appendicular skeleton?
What are the functions of the appendicular skeleton?
Protects organs involved in locomotion, excretion, reproduction and digestion
What are the functions of the axial skeleton?
Protection of organs (ribcage, skull)
Maintains upright posture, transmit weight down to lower extremities
What 3 bone groups comprise the skull?
What are the divisions of the vertebral column and how many bones in each?
Sacrum and coccyx
What are the divisions of the hand and how many bones in each?
Phalanges (3 per finger, 2 for thumb)
What are the divisions of the foot and how many bones in each?