Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Osseous Tissue

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Skeletal System 2 types of skeleton 1. Axial Skeleton bones that form longitudinal axis 2. Appendicular skeleton bones that form limbs and girdles Includes: a. joints flexibility and movement b. ligaments connective tissue…tough and flexible binds bones at joints c. cartilage connective tissue that is flexible and firm

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Fucntions of Bone 1.Support Framework supports and anchors all soft organs Legs support trunk 2.Protection Soft body organs Skull, vertebrae around spinal cord, rib cage 3.Movement Skeletal muscle attach to bone by tendons so can move

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Fucntions of Bone 4. Storage Fat and calcium Ca 2+ and phosphorus P 5. Blood cell formation (hematopoiesis) Within red marrow of spine, ribs, pelvis of adults Children have red marrow in most bones Yellow marrow is the marrow that is no longer producing red blood cells

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Bone  Adults = 206…Baby = 300 because of ossification (hardening to bony substance)  Ex: skull (soft spot), wrist  FYI: longest = femur…smallest = stirrup

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Bone A.Compact  Dense and smooth B.Spongy  Small pieces and open spaces

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Bone 1.Long Bone Longer than wide, heads at both ends Compact bone Ex: limbs (except at joints) 2.Short Bone Cube shaped Spongy bone Ex: joints…wrist, ankle, knee

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Bone 3.Flat Bone Thin, flat, curved Compact---spongy---compact layers Ex: skull, ribs, sternum 4.Irregular ”misc” that doesn’t fit in other 3 categories Ex: vertebrae and hip

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings

Gross Anatomy of a Long Bone  Diaphysis-Shaft  Compact bone  Epiphysis-Ends  Mostly Spongy bone Figure 5.2a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Diaphysis  Periosteum  Protective covering for diaphysis  Arteries  Supply nutrients  Perforating/Sharpey’s Fibers  Secure periosteum to bone Figure 5.2c

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Diaphysis cont…  Medullary cavity  Yellow marrow  Is “inactive” red marrow where red blood cell production occurred as an infant/childe  Fat storage in adults Figure 5.2a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Epiphysis  Articular cartilage  Covers epiphyses  Hyaline cartilage that provides smooth slippery surface that decreases friction at joint  Epiphyseal line  What’s left over from the epiphyseal plate (ie: growth plate)…causes lengthwise growth of long bone

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microscopic Anatomy of Bone Figure 5.3

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microscopic Anatomy of Bone  Osteocytes  Are mature bone cells  Make bone matrix  Lacunae  Cavities for osteocytes  Lamellae  Rings in which lacunae are arranged Detail of Figure 5.3

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microscopic Anatomy of Bone  Osteon  One unit of bone  Includes matrix of rings  Central (Haversian) canal  Lamellae circle around  Run lengthwise through bony matrix carrying blood vessels and nerves  Perforating ( Volkmann’s) canal  Communication pathway from outside bone to inside  Run into compact bone at right angles to shaft  Carry blood vessels/nerves throughout bone

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microscopic Anatomy of Bone  Canaliculus  Radiate from the central canal to lacunae  Connects all bone cells to matrix  Gathers nutrients Detail of Figure 5.3

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bone Growth  Hyaline cartilage = embryo  Replacing by bone = child  Bone = adult (except nose, ribs, joins, ears) Mostly bone except for certain places

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bone Growth…cont  Bones use hyaline cartilage as a model by ossification (ie: bone formation) 1.Hyaline cartilage is covered with bone matrix by osteoblasts (cells that form bone) 2.Hyaline cartilage model is digested and converted to bone EXCEPT: 1)Articular cartilage Covers bone ends Reduces friction at joints 2)Epiphyseal plate Growth in childhood

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings CHILDADULT

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bone Growth  Epiphyseal plates allow for growth  New cartilage formed  Formed continuously on external face of articular cartilage (outer covering) and epiphyseal plate (line beneath articular cartilage)  Older cartilage ossified  On internal face of articular cartilage is broken down and replaces with bony matrix  On top of articular cartilage and epiphyseal plate = CARTILAGE GROWS  Below articular cartilage and epiphyseal plate = REPLACED BY BONE

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings

Long Bone Formation and Growth Figure 5.4b

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings

Long Bone Formation and Growth Figure 5.4a