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
Osteons
the chief structural unit of compact (cortical) bone, consisting of concentric bone layers called lamellae, which surround a long hollow passageway, the Haversian canal
Haversian system
- concentric rings of calcified matrix surrounding a haversion canal
Haversian Canal
Any of the tiny, interconnecting, longitudinal channels in bone tissue through which blood vessels, nerve fibers, and lymphatics pass.
What connects haversian canals together in compact bone?
Volkman’s Canal
Volkman’s canal
connects haversian canals together in the compact bone
In spongy bone there is…
- latticework of thin plates of bone called trabeculae oriented along lines of stress
- the space between trabeculae is filled with red bone marrow
- found in ends of long bones and flat bones
What types of bone contain red bone marrow?
- flat bones (cranial, pelvic, ribs, and sternum)
- proximal humerus and femur
Whats another word for bone formation
ossification