Skeletal system Flashcards
What is the skeletal system composed of?
Cartilage, bone tissue, epithelial tissue, nerve, blood forming tissue, adipose tissue, and dense regular tissue
What are the 6 functions of bone?
Structure, support, blood cell formation, storage of minerals, protection, and movement
A typical long bone has what 3 major sections
- Epiphysis- end
- Metaphysis- just below epiphysis
- Diaphysis- middle
What kind of tissue is bone
Connective tissue
What are the 4 main types of bone cells
- Osteogenic cells (the ones that undergo mitosis)
- Osteoblast (loses ability to divide and gains ability to form matrix)
- Osteocyte (mature cell contained in hard matrix)
- Osteoclast (large cells formed by WBC to aid in bone growth, maintain, repair, and remodel)
Osteogenic cells
Young cells that undergo mitosis or become osteoblasts
- located beneath endosteum and periosteum
Osteoblasts
Form from osteogenic cells that lose there ability to divide and gain the ability to produce matrix
- located beneath endosteum and periosteum
Osteocytes
Mature bone cell that become surrounded by matrix and incased in lucunae
- located beneath endosteum and periosteum
Osteoclasts
(clean up) Formed from fused monocytes (WBC)
- located beneath endosteum and periosteum
- Secrete enzyme that dissolve bone matrix
- function in bone growth, maintenance, repair, remodelling
What is bone matrix made up of?
15% water
30% organic matrix (collagen fibres)
55% inorganic matrix (minerals & salts)
Mineralization is AKA
Calcification
Calcification is..
Hardening of tissue when mineral crystals deposit around collagen fibres
What 3 main components are in the bone matrix?
- Spaces for red bone marrow and vessels
- spongy bone that has many spaces
- compact bone that has vey few spaces
One way to classify bone
density; compact or spongy (cancellous) bone
Describe compact bone
- solid hard layer of bone
- makes up the shaft of long bone and external layers of all bones
- resist stresses from weight and movement
- composed of osteons