Hubs Bone Microatomic Structure

Question 1

Bone tissue components

Answer 1

2% connective tissue, 98% extracellular

Question 2

Bone extracellular organic component

Answer 2

33% - collagen (protein), proteoglycans(lublication gel)

Question 3

Bone extracellular inorganic component

Answer 3

67% -hydroxyapatite and other ca minerals

Question 4

Bone cells

Answer 4

Osteogenic, osteoblasts, osteocytes, osteoclasts

Question 5

Osteogenic cells

Answer 5

Stem cells that make osteoblasts

Question 6

Osteoblasts

Answer 6

Produce new bone matrix (and develop into osteocytes once surrounded by bone)

Question 7

Osteocytes

Answer 7

Nature bone cells-maintainers - recycle protein and minerals and communicate with other cells

Question 8

Osteoclasts

Answer 8

Destroyers - remove bone matrix

Question 9

Compact bone structure

Answer 9

Made of osteons containing circumferential lamallae surrounding a central canal for blood to reach osteocytes in the lacunae through canaliculi

Question 10

Osteon definition

Answer 10

Longitudinal unit within compact bone

Question 11

Lamallae definition

Answer 11

Series of cylicers formed of ECM around the central canal (forming shape and resisting forces )

Question 12

Lacunae definition

Answer 12

’ Lakes ‘ for osteocytes - where they sit

Question 13

Canaliculi

Answer 13

Channels for nutrients to travel to osteocytes through the ECM

Question 14

How does compact bone resist tension?

Answer 14

Osteons are aligned in the same direction to channel force- often along stress-lines

Question 15

Cancellous bone structure

Answer 15

Made of a network of trabeculae with marrow in the cavities and osteocytes within (in lacuna in between lannellae /on surface )

Question 16

How does cancellous bone resist compression?

Answer 16

Proximally-force channeled towards compact bone, distally-spreads force across joint surface. Based on trabecular shape and density

Question 17

How do bones grow wider?

Answer 17

Appositional growth -osteoblasts add bone outwards and osteoclasts remove some from the medullary cavity

Question 18

Bone homeostasis

Answer 18

Constant rate of formation/destruction - allows bone to change shape etc and mobilize minerals from the bone matrix

Question 19

What happens if OC > OB activity?

Answer 19

Osteopenia then osteoporosis ( clinically significant version)

Question 20

What is osteoporosis?

Answer 20

Loss of compact bone, thinning of cancellous, increased risk of fracture