Lecture 4 - Bone tissue and its microscopic structure Flashcards
What is Extracellular Matrix? (ECM)
The extracellular matrix helps cells attach to, and communicate with, nearby cells, and plays an important role in cell growth, cell movement, and other cell functions.
What two components make up ECM?
Inorganic (67%) and organic (33%)
What material mainly makes up Inorganic ECM?
Mineral salts
What material mainly makes up Organic ECM?
Collagen
What is the main function of Inorganic ECM?
Resists compression
What is the main function of Organic ECM?
Resists tension
What allows for blood supply in compact bone?
Foramina (Holes)
Define osteogenic cells
Stem cells that produce osteoblasts
Define osteoblasts
BUILDERS - Produce new bone matrix
Define osteoclasts
DESTROYERS - remove bone matrix
Define osteocytes
MAINTAINERS - Recycle protein and minerals from matrix. Mature bone cells
Define osteon
Longitudinal (lengthwise) unit within compact bone
Define lamellae
A series of cylinders formed of ECM around the central canal
Define canaliculi
Channels for osteocytes through ECM
What is bone homeostasis?
Balance of OB (osteoblasts) and OC (osteoclasts) activity.
What is another word for bone homeostasis?
Bone remodelling
What are two bone forming diseases?
Osteopenia and osteoporosis.
What is osteoporosis?
Imbalance of OB and OC activity, OC > OB
Define central canal
Inner part of bone, contains blood
vessel and nerves
How do bones grow wider? (Appositionally)
Combination of osteocyte, osteoclast and osteoblast activity
