skeletal cartilage contains no blood vessels or nerves contains no blood vessels or nerves...
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Skeletal CartilageSkeletal Cartilage
Contains no blood vessels or nervesContains no blood vessels or nerves Surrounded by the perichondrium (dense Surrounded by the perichondrium (dense
irregular connective tissue) that resists irregular connective tissue) that resists outward expansionoutward expansion
Three types – hyaline, elastic, and Three types – hyaline, elastic, and fibrocartilagefibrocartilage
Hyaline CartilageHyaline Cartilage
Provides support, flexibility, and resilienceProvides support, flexibility, and resilience Is the most abundant skeletal cartilageIs the most abundant skeletal cartilage Is present in these cartilages:Is present in these cartilages:
Articular – covers the ends of long bonesArticular – covers the ends of long bones Costal – connects the ribs to the sternumCostal – connects the ribs to the sternum Respiratory – makes up larynx, reinforces air Respiratory – makes up larynx, reinforces air
passagespassages Nasal – supports the noseNasal – supports the nose
Elastic CartilageElastic Cartilage
Similar to hyaline cartilage, but contains Similar to hyaline cartilage, but contains elastic fiberselastic fibers
Found in the external ear and the epiglottisFound in the external ear and the epiglottis
FibrocartilageFibrocartilage
Highly compressed with great tensile strengthHighly compressed with great tensile strength Contains collagen fibersContains collagen fibers Found in menisci of the knee and in Found in menisci of the knee and in
intervertebral discsintervertebral discs
Growth of CartilageGrowth of Cartilage
Appositional – cells in the perichondrium Appositional – cells in the perichondrium secrete matrix against the external face of secrete matrix against the external face of existing cartilageexisting cartilage
Interstitial – lacunae-bound chondrocytes Interstitial – lacunae-bound chondrocytes inside the cartilage divide and secrete new inside the cartilage divide and secrete new matrix, expanding the cartilage from withinmatrix, expanding the cartilage from within
Calcification of cartilage occursCalcification of cartilage occurs During normal bone growthDuring normal bone growth During old ageDuring old age
Bones and Cartilages of the Human Bones and Cartilages of the Human BodyBody
Figure 6.1
Classification of BonesClassification of Bones
Axial skeleton – bones of the skull, vertebral Axial skeleton – bones of the skull, vertebral column, and rib cagecolumn, and rib cage
Appendicular skeleton – bones of the upper Appendicular skeleton – bones of the upper and lower limbs, shoulder, and hipand lower limbs, shoulder, and hip
Classification of Bones: By ShapeClassification of Bones: By Shape
Long bones – Long bones – longer than longer than they are wide they are wide
(e.g., (e.g., humerus)humerus)
Figure 6.2a
Classification of Bones: By ShapeClassification of Bones: By Shape
Short bonesShort bones Cube-shaped Cube-shaped
bones of the bones of the wrist and wrist and ankleankle
Bones that Bones that form within form within tendons (e.g., tendons (e.g., patella)patella)
Figure 6.2b
Classification of Bones: By ShapeClassification of Bones: By Shape
Flat bones – Flat bones – thin, thin, flattened, flattened, and a bit and a bit curved (e.g., curved (e.g., sternum, and sternum, and most skull most skull bones)bones)
Figure 6.2c
Classification of Bones: By ShapeClassification of Bones: By Shape
Irregular Irregular bones – bones – bones with bones with complicated complicated shapes (e.g., shapes (e.g., vertebrae vertebrae and hip and hip bones)bones)
Figure 6.2d
Function of BonesFunction of Bones
Support – form the framework that supports Support – form the framework that supports the body and cradles soft organsthe body and cradles soft organs
Protection – provide a protective case for the Protection – provide a protective case for the brain, spinal cord, and vital organsbrain, spinal cord, and vital organs
Movement – provide levers for musclesMovement – provide levers for muscles
Function of BonesFunction of Bones
Mineral storage – reservoir for minerals, Mineral storage – reservoir for minerals, especially calcium and phosphorusespecially calcium and phosphorus
Blood cell formation – hematopoiesis occurs Blood cell formation – hematopoiesis occurs within the marrow cavities of boneswithin the marrow cavities of bones
Bone MarkingsBone Markings
Bulges, depressions, and holes that serve as: Bulges, depressions, and holes that serve as: Sites of attachment for muscles, ligaments, and Sites of attachment for muscles, ligaments, and
tendonstendons Joint surfacesJoint surfaces Conduits for blood vessels and nervesConduits for blood vessels and nerves
Bone Markings: Projections – Bone Markings: Projections – Sites of Muscle and Ligament Sites of Muscle and Ligament
AttachmentAttachment
Tuberosity – rounded projectionTuberosity – rounded projection Crest – narrow, prominent ridge of boneCrest – narrow, prominent ridge of bone Trochanter – large, blunt, irregular surfaceTrochanter – large, blunt, irregular surface Line – narrow ridge of boneLine – narrow ridge of bone
Tubercle – small rounded projectionTubercle – small rounded projection Epicondyle – raised area above a condyleEpicondyle – raised area above a condyle Spine – sharp, slender projectionSpine – sharp, slender projection Process – any bony prominenceProcess – any bony prominence
Bone Markings: Projections – Bone Markings: Projections – Sites of Muscle and Ligament Sites of Muscle and Ligament
AttachmentAttachment
Bone Markings: Projections – Bone Markings: Projections – Projections That Help to Form Projections That Help to Form
JointsJoints Head – bony expansion carried on a narrow Head – bony expansion carried on a narrow
neckneck Facet – smooth, nearly flat articular surfaceFacet – smooth, nearly flat articular surface Condyle – rounded articular projectionCondyle – rounded articular projection Ramus – armlike bar of boneRamus – armlike bar of bone
Bone Markings: Depressions and Bone Markings: Depressions and OpeningsOpenings
Meatus – canal-like passagewayMeatus – canal-like passageway Sinus – cavity within a boneSinus – cavity within a bone Fossa – shallow, basin-like depressionFossa – shallow, basin-like depression Groove – furrowGroove – furrow Fissure – narrow, slit-like openingFissure – narrow, slit-like opening Foramen – round or oval opening through a Foramen – round or oval opening through a
bonebone
Gross Anatomy of Bones: Bone Gross Anatomy of Bones: Bone TexturesTextures
Compact bone – dense outer layerCompact bone – dense outer layer Spongy bone – honeycomb of trabeculae filled Spongy bone – honeycomb of trabeculae filled
with yellow bone marrowwith yellow bone marrow
Bone MarkingsBone Markings
Table 6.1
Structure of Long BoneStructure of Long Bone
Long bones consist of a diaphysis and an Long bones consist of a diaphysis and an epiphysisepiphysis
DiaphysisDiaphysis Tubular shaft that forms the axis of long bonesTubular shaft that forms the axis of long bones Composed of compact bone that surrounds the Composed of compact bone that surrounds the
medullary cavitymedullary cavity Yellow bone marrow (fat) is contained in the Yellow bone marrow (fat) is contained in the
medullary cavitymedullary cavity
Structure of Long BoneStructure of Long Bone
EpiphysesEpiphyses Expanded ends of long bonesExpanded ends of long bones Exterior is compact bone, and the interior is Exterior is compact bone, and the interior is
spongy bonespongy bone Joint surface is covered with articular (hyaline) Joint surface is covered with articular (hyaline)
cartilagecartilage Epiphyseal line separates the diaphysis from the Epiphyseal line separates the diaphysis from the
epiphysesepiphyses
Structure of Long BoneStructure of Long Bone
Figure 6.3
Structure of Long BoneStructure of Long Bone
Figure 6.3a
Structure of Long BoneStructure of Long Bone
Figure 6.3b
Structure of Long BoneStructure of Long Bone
Figure 6.3c
Bone MembranesBone Membranes
Periosteum – double-layered protective Periosteum – double-layered protective membranemembrane Outer fibrous layer is dense regular connective tissueOuter fibrous layer is dense regular connective tissue Inner osteogenic layer is composed of osteoblasts Inner osteogenic layer is composed of osteoblasts
and osteoclastsand osteoclasts Richly supplied with nerve fibers, blood, and Richly supplied with nerve fibers, blood, and
lymphatic vessels, which enter the bone via nutrient lymphatic vessels, which enter the bone via nutrient foraminaforamina
Secured to underlying bone by Sharpey’s fibersSecured to underlying bone by Sharpey’s fibers
Bone MembranesBone Membranes
Endosteum – delicate membrane covering Endosteum – delicate membrane covering internal surfaces of boneinternal surfaces of bone
Structure of Short, Irregular, Structure of Short, Irregular, and Flat Bonesand Flat Bones
Thin plates of periosteum-covered compact Thin plates of periosteum-covered compact bone on the outside with endosteum-covered bone on the outside with endosteum-covered spongy bone (diploë) on the insidespongy bone (diploë) on the inside
Have no diaphysis or epiphysesHave no diaphysis or epiphyses Contain bone marrow between the trabeculaeContain bone marrow between the trabeculae
Structure of a Flat BoneStructure of a Flat Bone
Figure 6.4
Location of Hematopoietic Tissue Location of Hematopoietic Tissue
(Red Marrow)(Red Marrow) In infantsIn infants Found in the medullary cavity and all areas of Found in the medullary cavity and all areas of
spongy bone spongy bone In adultsIn adults
Found in the diploë (between inner and outer Found in the diploë (between inner and outer walls) of flat bones, and the head of the femur and walls) of flat bones, and the head of the femur and humerushumerus
Microscopic Structure of Bone: Microscopic Structure of Bone: Compact BoneCompact Bone
Haversian system, or osteon – the structural Haversian system, or osteon – the structural unit of compact boneunit of compact bone Lamella – weight-bearing, column-like matrix Lamella – weight-bearing, column-like matrix
tubes composed mainly of collagentubes composed mainly of collagen Haversian, or central canal – central channel Haversian, or central canal – central channel
containing blood vessels and nervescontaining blood vessels and nerves Volkmann’s canals – channels lying at right angles Volkmann’s canals – channels lying at right angles
to the central canal, connecting blood and nerve to the central canal, connecting blood and nerve supply of the periosteum to that of the Haversian supply of the periosteum to that of the Haversian canalcanal
Microscopic Structure of Bone: Microscopic Structure of Bone: Compact BoneCompact Bone
Osteocytes – mature bone cellsOsteocytes – mature bone cells Lacunae – small cavities in bone that contain Lacunae – small cavities in bone that contain
osteocytesosteocytes Canaliculi – hairlike canals that connect Canaliculi – hairlike canals that connect
lacunae to each other and the central canallacunae to each other and the central canal
Microscopic Structure of Bone: Microscopic Structure of Bone: Compact BoneCompact Bone
Figure 6.6a, b
Microscopic Structure of Bone: Microscopic Structure of Bone: Compact BoneCompact Bone
Figure 6.6a
Microscopic Structure of Bone: Microscopic Structure of Bone: Compact BoneCompact Bone
Figure 6.6b
Microscopic Structure of Bone: Microscopic Structure of Bone: Compact BoneCompact Bone
Figure 6.6c
Chemical Composition of Bone: Chemical Composition of Bone: OrganicOrganic
Osteoblasts – bone-forming cellsOsteoblasts – bone-forming cells Osteocytes – mature bone cellsOsteocytes – mature bone cells Osteoclasts – large cells that resorb or break Osteoclasts – large cells that resorb or break
down bone matrixdown bone matrix Osteoid – unmineralized bone matrix Osteoid – unmineralized bone matrix
composed of proteoglycans, glycoproteins, composed of proteoglycans, glycoproteins, and collagenand collagen
Chemical Composition of Bone: Chemical Composition of Bone: InorganicInorganic
Hydroxyapatites, or mineral saltsHydroxyapatites, or mineral salts Sixty-five percent of bone by massSixty-five percent of bone by mass Mainly calcium phosphatesMainly calcium phosphates Responsible for bone hardness and its resistance to Responsible for bone hardness and its resistance to
compressioncompression
Bone DevelopmentBone Development
Osteogenesis and ossification – the process of Osteogenesis and ossification – the process of bone tissue formation, which leads to:bone tissue formation, which leads to: The formation of the bony skeleton in embryosThe formation of the bony skeleton in embryos Bone growth until early adulthoodBone growth until early adulthood Bone thickness, remodeling, and repairBone thickness, remodeling, and repair
Formation of the Bony SkeletonFormation of the Bony Skeleton
Begins at week 8 of embryo developmentBegins at week 8 of embryo development Intramembranous ossification – bone develops Intramembranous ossification – bone develops
from a fibrous membranefrom a fibrous membrane Endochondral ossification – bone forms by Endochondral ossification – bone forms by
replacing hyaline cartilagereplacing hyaline cartilage
Intramembranous OssificationIntramembranous Ossification
Formation of most of the flat bones of the Formation of most of the flat bones of the skull and the claviclesskull and the clavicles
Fibrous connective tissue membranes are Fibrous connective tissue membranes are formed by mesenchymal cellsformed by mesenchymal cells