PowerPoint Lecture Slides prepared by Barbara Heard, Atlantic Cape Community College Ninth Edition Human Anatomy & Physiology C H A P T E R 6 Annie Leibovitz/Contact Press Images 2013 Pearson Education, Inc.
Classification of Bones Bones Are classified by: Shape Internal tissue organization Bone markings (surface features; marks)
Sutural Bones Sutures Sutural bone Small, extra
Irregular Bones Vertebra Complex
Short Bones Carpal bones Small, thick
Flat Bones Parietal bone External table thin, parallel
Long Bones Humerus Long
Figure 6-1f A Classification of Bones by Shape Sesamoid Bones Patella In ligaments
Bone (Osseous) Tissue Internal sections of bone differ Long vs. Flat
Spongy bone Epiphysis Metaphysis Diaphysis/Epiphysis meet Grows! Compact bone Diaphysis (shaft) Compact bone wall Center-medullary Medullary cavity Metaphysis Epiphysis Articulation Spongy Compact covering
sandwich of spongy bone function? Cortex (compact bone) Diploë (spongy bone)
Osseous Tissue: Cellular Level
Bone (Osseous) Tissue Bone Cells Make up only 2% of bone mass Four types of cells
Bone (Osseous) Tissue Osteocytes Mature bone cells Two major functions of osteocytes 1. maintain protein and minerals 2. repair
Figure 6-3 Types of Bone Cells Canaliculi Osteocyte Matrix
Bone (Osseous) Tissue Osteoblasts Immature bone cells blast = sprout produce bone Osteoblasts osteocytes
Matrix Osteoid Osteoblast
Bone (Osseous) Tissue Osteoprogenitor Cells Mesenchymal cells divide osteoblasts Located in two layers: in endosteum medullary cavity lining In periosteum Assist in fracture repair
Osteoprogenitor cell Medullary cavity Endosteum
Bone (Osseous) Tissue Osteoclasts Greek for broken Dissolve matrix release stored minerals Giant, multinucleate cells Derived from stem cells that produce macrophages
Medullary cavity Osteoclast Matrix Very different than other bone cells
COMPACT vs. SPONGY
Figure 6-4b The Histology of Compact Bone Osteon Compact Bone Lacunae Central canals Lamellae Osteons SEM 182
Compact Bone Central canal Functional Unit: Osteon Concentric lamellae Endosteum The organization of osteons and lamellae in compact bone
Compact Bone Collagen fiber orientation Orthogonal Think concrete and rebar
Compact Bone and Spongy Bone Spongy Bone Trabeculae no blood vessels Filled: red bone marrow RBC formation supplies nutrients to osteocytes Yellow bone marrow In some bones, spongy bone holds yellow bone marrow yellow because it stores fat more blood needed? yellow red
Figure 6-6 The Structure of Spongy Bone Trabeculae of spongy bone Canaliculi opening on surface Endosteum Lamellae
Bone Growth
Bone Formation and Growth Bone Development Human bones grow until about age 25 how does bone osteogenesis happen? Two ways:
Bone Formation and Growth Endochondral Ossification Endochondral hyaline cartilage model Most bones Six steps
Hyaline Cartilage Model Cartilage enlarges
Blood vessels form Mesenchyme osteoblast Epiphysis Shaft ensheathed in bone: -periosteal bone collar Diaphysis
Vessels penetrate -Periosteal bud invades Medullary cavity Spongy bone ossification center Bone toward ends Blood vessel Primary ossification center Superficial bone Spongy bone
Remodeling Medullary cavity opened Medullary cavity Metaphysis
Hyaline cartilage Secondary ossification centers @ epiphyses Epiphysis Metaphysis Periosteum Compact bone Secondary ossification center
Epiphysis filled Hyaline cartilage left for joint Spongy bone Articular cartilage Model continues to elongate -so, bone chases cartilage Epiphyseal cartilage Diaphysis
Bone Formation and Growth Appositional Growth Thickening of bone Compact bone thickens and strengthens long bone with layers of circumferential lamellae
Figure 6-11b Bone Growth at an Epiphyseal Cartilage
Bone Formation and Growth Intramembranous Ossification Intramembranous Also called dermal ossification occurs in the dermis No cartilage model dermal bones Skull mandible (lower jaw) clavicle (collarbone) Four main steps:
Step 1 Mesenchymal cells osteoblast Mesenchymal cell Ossification starts Spicules spread Spicules??? Osteoblast
Step 2 Osteoblast Osteoid Matrix Osteocyte
Step 3 Mesenchyme periosteum Trebeculae Blood vessel surrounded
Trebeculae compact bone Step 4 Diploë
Abnormalities in bone growth
Fibrodysplasia ossificans progressiva (FOP) autosomal dominant, Codon 206: Arg Hist 1 : 2, 000, 000 endothelial cells mesenchymal cells bone
Marfan Syndrome Genetic condition Excessive growth of cartilage Aorta stretches Heart enlarged Excessive growth of long bones