Chapter 6 Highlights

Question 1

Composition of organic bone matrix

Answer 1

Composed of collagen and proteoglycans

Question 2

Composition of inorganic bone matrix

Answer 2

Ca3(PO4)2 and calcium hydroxide combine to form hydoyapetite crystals

Question 3

What happens when you remove the organic bone matrix?

Answer 3

Bone without its organic matrix is brittle and shatters easily

Question 4

What happens when you remove the inorganic bone matrix?

Answer 4

Bone without its inorganic matrix cannot resist compression

Question 5

Structure of compact bone

Answer 5

Unit = osteon

Question 6

Lamellae

Answer 6

Layers of bone

Question 7

Types of lamellae

Answer 7

• Concentric
• Interstitial
• Circumferential

Question 8

Perforating canals

Answer 8

Connects central canals

Question 9

Trabeculae

Answer 9

• Struts or ribs of bone covered in endosteum

- Not arranged into osteons

Question 10

Intramembranous ossification

Answer 10

Occurs in connective tissue membrane

Question 11

Endochondral ossification

Answer 11

Takes place in cartilage

Question 12

What happens when calcium is low?

Answer 12

• Parathyroid gland secretes PTH
• PTH causes kidneys and small intestine to absorb calcium and phosphate
• Kidneys release calcitriol, which causes kidneys and small intestine to absorb calcium and phosphate
• Goes to the bones and increases activity of osteoclast
• Osteoclasts release calcium and phosphate into the blood

Question 13

What happens when calcium is high?

Answer 13

• C cell of thyroid gland secretes calcitonin
• Causes kidneys and small intestine to not absorb calcium and phosphate
• It will go to the bones and indirectly inhibit PTH from activating osteoclast
• Osteoblast will deposit calcium and phosphate back into the bone

Question 14

Greenstick fracture

Answer 14

Incomplete fracture that occurs on the convex side of the curve of a bone