Osteology

Question 1

Bone Tissue

Answer 1

• composed of approximately 1/3 organic matter (i.e. bone cells, blood vessels, membranes (endosteum and periosteum) and bone marrow
• Other 2/3 inorganic matter is mostly hydroxyapatite

Question 2

“Rubber Bone”

Answer 2

• Type of preparation that results from the removal of all inorganic materials leaving a purely organic remnant

Question 3

Types of Bone

(5)

Answer 3

• Long bones
• short bones
• flat bones
• irregular bones
• sesamoid bones

Question 4

Intramembranous Ossification

Answer 4

• 1 of 2 mechanisms by which mammalian bone develops
• involves direct formation of bone tissue within a condensed mesenchymal model of the bone
• Largely confined to flat bones of the skull
• the embryonic development of flat bones from an embryonic tissue called the mesenchyme

Question 5

Endochondral Ossification

Answer 5

• bone is first represented as a cartinlaginous model subsequently replaced by bone tissue
• MAJORITY OF MAMMALIAN bones form this way
• Typically, several seperate centres of ossification are formed within the cartilaginous model (e.g. one in the centre of the shaft along the bone, the primary or diaphyseal centre and one at either extremity, secondary or epiphyseal centres)

Question 6

Epiphyseal Cartilage

“Growth Plate”

Answer 6

• The cartilage persisting initially between the separate centres of ossification during bone growth
• Acts as an important site for growth in length of a long bone during early life
• Note: These features are clearly discernable on radiographs

Question 7

Articular Cartilage

Answer 7

• Articular cartilage is the smooth, white tissue that covers the ends of bones where they come together to form joints.
• A further and permanent remnant of the cartilaginous model is the layer of cartilage on the extremeties of long bones which contributes to the moveable joints formed by that bone