Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Human Anatomy & Physiology SEVENTH EDITION Elaine N. Marieb Katja Hoehn PowerPoint ® Lecture Slides prepared by Vince Austin, Bluegrass Technical and Community College C H A P T E R 6 Bones and Skeletal Tissues P A R T A

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bones and Cartilages of the Human Body Figure 6.1

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Bones  Axial skeleton – bones of the skull, vertebral column, and rib cage  Appendicular skeleton – bones of the upper and lower limbs, shoulder, and hip

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Bones: By Shape  Long bones – longer than they are wide (e.g., humerus) Figure 6.2a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Bones: By Shape  Short bones; cubelike  e.g. cube-shaped bones of the wrist and ankle Figure 6.2b

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Bones: By Shape Sesamoid Bones form within tendons (e.g., patella) Figure 6.2b

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Bones: By Shape  Flat bones – thin, flattened, and a bit curved (e.g., sternum, scapulae, ribs, and most skull bones) Figure 6.2c

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Classification of Bones: By Shape  Irregular bones – bones with complicated shapes (e.g., vertebrae and hip bones) Figure 6.2d

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Function of Bones  Support – form the framework that supports the body and cradles soft organs  Protection – provide a protective case for the brain, spinal cord, and vital organs

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Function of Bones  Movement – provide levers for muscles (muscle attachment)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Function of Bones  Mineral storage – reservoir for minerals, especially calcium and phosphorus  Blood cell formation – hematopoiesis occurs within the marrow cavities of bones

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bone Markings  Bulges, depressions, and holes that serve as:  Sites of attachment for muscles, ligaments, and tendons  Joint surfaces  Conduits for blood vessels and nerves

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bone Markings: Projections – Sites of Muscle and Ligament Attachment  Tuberosity – rounded projection  Crest – narrow, prominent ridge of bone  Trochanter – large, blunt, irregular surface  Line – narrow ridge of bone

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  Tubercle – small rounded projection  Epicondyle – raised area above a condyle  Spine – sharp, slender projection  Process – any bony prominence Bone Markings: Projections – Sites of Muscle and Ligament Attachment

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bone Markings: Projections – Projections That Help to Form Joints  Head – bony expansion carried on a narrow neck  Facet – smooth, nearly flat articular surface  Condyle – rounded articular projection  Ramus – armlike bar of bone

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Bone Markings: Depressions and Openings  Meatus – canal-like passageway  Sinus – cavity within a bone  Fossa – shallow, basin-like depression  Groove – furrow  Fissure – narrow, slit-like opening  Foramen – round or oval opening through a bone

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bone Markings Table 6.1

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Gross Anatomy of Bones: Bone Textures  Compact bone – dense outer layer; solid, strong & resists bending  Spongy bone – honeycomb of trabeculae filled with red or yellow bone marrow ( in living bones)  Also called cancellous bone  Reduces weight of skeleton

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Structure of Long Bone  Long bones consist of a diaphysis and an epiphysis  Diaphysis  Tubular shaft that forms the axis of long bones  Composed of compact bone that surrounds the medullary cavity  Yellow bone marrow (fat) is contained in the medullary cavity

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structure of Long Bone  Epiphyses  Expanded ends of long bones  Exterior is compact bone, and the interior is spongy bone to reduce weight of skeleton  Joint surface is covered with articular (hyaline) cartilage  Epiphyses “articulate” with other bones  Epiphyseal line separates the diaphysis from the epiphyses

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structure of Long Bone Figure 6.3

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structure of Long Bone Figure 6.3a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structure of Long Bone Figure 6.3b

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bone Membranes  Periosteum – double-layered protective membrane—place where new bone cells arise  Outer fibrous layer is dense regular connective tissue  Inner osteogenic layer is composed of osteoblasts and osteoclasts  Vascular; richly supplied with nerve fibers, blood, and lymphatic vessels, which enter the bone via nutrient foramina  Continuous with ligaments and tendons  Secured to underlying bone by Sharpey’s fibers

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structure of Long Bone Figure 6.3c

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bone Membranes  Endosteum – delicate membrane covering internal surfaces of bone  Surrounds medullary cavities  Thin layer of squamous epithelium

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Structure of Short, Irregular, and Flat Bones  Thin plates of periosteum-covered compact bone on the outside with endosteum-covered spongy bone (diploë) on the inside  Have no diaphysis or epiphyses  Contain bone marrow between the trabeculae

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structure of a Flat Bone Figure 6.4

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Location of Hematopoietic Tissue (Red Marrow)  In infants  Found in the medullary cavity and all areas of spongy bone  In adults  Found in the diploë of flat bones, and the head of the femur and humerus (specifically at base of skull, ribs, sternum, pelvis, vertebrae, clavicles and ends of long bones)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microscopic Structure of Bone: Compact Bone  Tightly packed  Haversian system, or osteon – the structural unit of compact bone  Lamella – weight-bearing, column-like matrix tubes composed mainly of collagen (gives strength & resilience)  Haversian, or central canal – central channel containing blood vessels and nerves  Volkmann’s canals – channels lying at right angles to the central canal, connecting blood and nerve supply of the periosteum to that of the Haversian canal (also called perforating canals)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microscopic Structure of Bone: Compact Bone  Osteocytes – mature bone cells  Lacunae – small cavities in bone that contain osteocytes  Canaliculi – hairlike canals that connect lacunae to each other and the central canal

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microscopic Structure of Bone: Compact Bone Figure 6.6a, b

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microscopic Structure of Bone: Compact Bone Figure 6.6a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microscopic Structure of Bone: Compact Bone Figure 6.6b

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microscopic Structure of Bone: Compact Bone Figure 6.6c

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microscopic Structure of Spongy Bone  Consists of small, needlelike pieces with much open space  No osteons; nutrients received through diffusion

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Chemical Composition of Bone: Organic  Osteoblasts – bone-forming cells (embryonic)  Osteocytes – mature bone cells  Osteoclasts – large cells that resorb or break down bone matrix (dissolve bone)  Osteoid – unmineralized bone matrix composed of proteoglycans, glycoproteins, and collagen

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Chemical Composition of Bone: Inorganic  Hydroxyapatites, or mineral salts  Sixty-five percent of bone by mass  Mainly calcium phosphates  Responsible for bone hardness and its resistance to compression

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bone Development  Osteogenesis and ossification – the process of bone tissue formation, which leads to:  The formation of the bony skeleton in embryos  Bone growth until early adulthood  Bone thickness, remodeling, and repair

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Formation of the Bony Skeleton  Bones form by replacing connective tissue in the fetus  Some form within sheetlike layers of connective tissue (intramembranous bones)  Others form by replacing masses of cartilage (endochondral bones)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Formation of the Bony Skeleton  Begins at week 8 of embryo development  Intramembranous ossification – bone develops from a fibrous membrane  Forms most of the flat bones of the skull and the clavicles  Endochondral ossification – bone forms by replacing hyaline cartilage  Forms most bones of skeleton below the base of the skull (except for the clavicles)

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Endochondral Ossification  Begins in the second month of development  Uses hyaline cartilage “bones” as models for bone construction  Requires breakdown of hyaline cartilage prior to ossification  Primary center of ossification: diaphysis  Secondary center of ossification: epiphysis  Epiphyseal disk/suture—seen when both centers fuse (ossification complete)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Formation of bone collar around hyaline cartilage model. Hyaline cartilage Cavitation of the hyaline carti- lage within the cartilage model. Invasion of internal cavities by the periosteal bud and spongy bone formation. Formation of the medullary cavity as ossification continues; appearance of sec- ondary ossification centers in the epiphy- ses in preparation for stage 5. Ossification of the epiphyses; when completed, hyaline cartilage remains only in the epiphyseal plates and articular cartilages. Deteriorating cartilage matrix Epiphyseal blood vessel Spongy bone formation Epiphyseal plate cartilage Secondary ossificaton center Blood vessel of periosteal bud Medullary cavity Articular cartilage Spongy bone Primary ossification center Bone collar

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings  Epiphyseal plates are responsible for lengthening bones, while increases in thickness are due to appositional growth underneath the periosteum  A medullary cavity forms in the diaphysis due to the activity of osteoclasts

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Skeletal Organization  The axial skeleton:  Skull  Hyoid bone  Vertebral column (vertebrae & intervertebral disks)  Thorax (ribs & sternum)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Skeletal Organization cont’d  Appendicular Skeleton:  Pectoral girdle (scapulae & clavicles)  Upper limbs (humerus, radius, ulna, carpals, metacarpals, phalanges)  Pelvic girdle (coxal bones articulating with the sacrum)  Lower limbs (femur, tibia, patella, tarsals, metatarsals, phalanges)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Red = AxialYellow = Appendicular

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

 Normal number of bones in human body: 206