types and histology of bones
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Types and Histology of Bones. Ch. 6. 4 types of bones. Long Short Flat Irregular. Other Types of Bones. Sutural or Wormian bones – small bones located between joints of ___________ bones - PowerPoint PPT PresentationTRANSCRIPT
Types and Histology of Bones
Ch. 6
4 types of bones
• Long• Short• Flat• Irregular
Other Types of Bones
• Sutural or Wormian bones – small bones located between joints of ___________ bones
• Sesamoid bones – small bones wrapped in ______________ where pressure is great – patella (knee cap)
4 types of bone
• Long bone– _________________ – Longer than they are wide– Ex: femur, humerus
4 types of bone
• Short bones– As long as they are wide– Sometimes have
_____________ shape
4 types of bone
• Flat bones– When bone tissue
invades and hardens fibrous membranes
– They are ___________ in shape
– Usually ____________ rather than flat
4 types of bone
• Irregular– ______________ in shape– Do not fit into other categories
2 types of skeletons
• Axial – 80 bones– ______________ axis of
skeleton– 28 are skull bones– 26 vertebrae– 25 rib cage bones– 1 unattached hyoid bone
2 types of skeletons
• Appendicular skeleton– 126 ______________ bones– Includes bones of
_____________ – 64 bones in upper
extremities– 62 bones in lower
extremities
Bone Histology
• Made up of matrix of– 25% __________– 25% protein– 50% mineral salts
• 4 types of cells– Osteoprogenitor cells– Osteoblasts– Osteocytes– Osteoclasts
4 types of cells
• Osteoprogenitor cells– Osteo = bone, pro = precursor, gen = to produce– Unspecialized cells – Stem cells– Undergo mitosis and develop into osteoblasts– Found in: inner periosteum, endosteum, and in
canals
4 types of cells
• Osteoblasts– Cells that form bone– Lost ability to divide– Secretes collagen which helps build bones– Found on surface of bones
4 types of cells
• Osteoclasts– Develop from circulating
monocytes (WBC)– Settles on surface of bone– Function is bone
resorption (destroying matrix)
– Helps development, growth, maintenance and repair of bone
4 types of cells
• Osteocytes– Mature bone cells from
osteoblasts– Principal cells of bone
tissue– Can’t divide– Maintains cellular activity
• Exchange of nutrients and waste with blood
• Calcium absorption
2 regions of bone
• Compact and spongyor cancellous tissue
Compact bone
• External layers of bone• Protection and support• Helps long bones resist stress of weight on them• Tensile strength – resistance to being stretched
apart• Haversian canals – openings for blood vessels• Volkmann’s canals – opening for blood vessels
that are perpendicular to Haversian canals
Compact bone
Spongy bone
• No true osteons• Makes up epiphysis of long bones• In hips, ribs, sternum, spine, skull and end of
bones• Sites of red bone marrow storage• Trabeculae – thin plates of lamellae
Spongy bone