Chapter 6 Bones and Skeletal Tissues - PowerPoint Presentation

Slide1

Chapter 6Bones and Skeletal Tissues

Part B

Bone StructureSlide2

BonesBones are organs!Contains various types of tissuesOsseous tissue (dominates)

Nervous tissue

Cartilage

Fibrous connective tissue (lining cavities)

Muscle and epithelial tissues in blood vesselsSlide3

BonesWe will look at bone structure on three levelsGrossMicroscopicChemicalSlide4

Bone Structure

Gross Anatomy

Bone Markings, Bone Textures, Bone StructuresSlide5

Bone MarkingsSurface features of bonesSites for attachments for muscles, tendons and ligamentsJoint surfaces

Passages for nerves and blood vesselsSlide6

Bone MarkingsCategories of bone markingsProjections Bulges that grow outward from the bone surfaceDepressions and openingsIndentations, holes, and cavities

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Projections That Are Sites of Muscle and Ligament AttachmentTuberosity – rounded projectionCrest

– narrow, prominent ridge of bone

Trochanter

– large, blunt, irregular surface

Line

– narrow ridge of bone

Tubercle

– small rounded projection

Epicondyle

– raised area above a

condyle

Spine

– sharp, slender projection

Process

– any bony prominenceSlide8

Projections That help to Form JointsHead – bony expansion carried on a narrow neckFacet

– smooth, nearly flat

articular

surface

Condyle

– rounded

articular

projection

Ramus

–

armlike

bar of boneSlide9

Depressions and Openings Allowing Blood Vessels & Nerves to PassMeatus – canal-like passageway

Sinus

– cavity within a bone

Fossa

– shallow,

basinlike

depression

Groove

– furrow

Fissure

– narrow,

slitlike

opening

Foramen

– round or oval opening through a boneSlide10

Bone TexturesCompact bone – dense outer layerLooks solid to the eye

Spongy bone

– honeycomb or spongy appearance

Has small needle-like or flat pieces called

trabeculae

filled with red or yellow bone marrowSlide11

Structure of Long BoneGeneral structure of Long BonesDiaphysisEpiphysesMembranesSlide12

Structure of Long BoneDiaphysisShaft constructed of a thick collar of compact bone that surrounds the medullary

cavitySlide13

Structure of Long BoneMedullary CavityCavity of the shaftContains yellow marrow (mostly fat) in adults

Contains red marrow (for blood cell formation) in infantsSlide14

Structure of Long BoneEpiphysesExpanded ends of long bonesExterior is compact bone, interior is spongy boneJoint surface is covered with

articular

cartilage

Epiphyseal

line separates the

diaphysis

from the epiphysesSlide15

Structure of Long BoneArticular cartilageCovers the external surface of the epiphysesMade of hyaline cartilage

Decreases friction at joint surfacesSlide16

Structure of Long BoneEpiphyseal LineRemnant of epiphyseal plate

Disc of hyaline cartilage that grows during childhood to lengthen the boneSlide17

Structure of Long BoneMembranes of long bonesPeriosteumEndosteumSlide18

Structure of Long BonePeriosteumOutside covering of the boneExcept joint surfacesGlistening white, double-layered membrane

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Structure of Long BonePeriosteumOuter Fibrous layer is dense connective tissue Inner osteogenic layer (next to bone surface) is mostly osteoblasts (bone germinators) and osteoclasts (bone breakers)Slide20

Structure of Long BonePeriosteumRichly supplied with nerve fibers, lymphatic vessels, blood vessels which enter the diaphysis by a nutrient foramen (opening)Slide21

Structure of Long BoneSharpey’s fibersSecures periosteum to underlying bone

Made of collagen fibers

Extends into bone matrixSlide22

Structure of Long BoneArteriesSupplies bone cells with nutrientsSlide23

Structure of Long BoneEndosteumDelicate connective tissueContains osteoblasts

&

osteoclastsSlide24

Structure of Long BoneEndosteumCovers internal surfaces of boneMedullary cavity

Trabeculae

(spongy)

Canals through compact boneSlide25

Structure of Long BoneFigure 6.3Slide26

Structure of Short, Irregular, and Flat BonesSlide27

Structure of Short, Irregular, and Flat BonesThin plates of periosteum-covered compact bone on the outside with endosteum

-covered

diploë

on the inside

Spongy bone in flat bone is called

diploëSlide28

Structure of Short, Irregular, and Flat BonesHave no diaphysis or epiphyses

Contain bone marrow between the

trabeculae

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Red Bone MarrowHematopoietic TissueSlide30

Location of Hematopoietic Tissue (Red Marrow)In infants

Found in the

medullary

cavity and all areas of spongy bone Slide31

Location of Hematopoietic Tissue (Red Marrow)In adultsFound in the diploë

of flat bones, and the head of the femur and

humerus

Remember, the

diploë

is the spongy bone of flat bones Slide32

Yellow Bone MarrowYellow marrow is found in the medullary cavities Yellow marrow can revert back to red marrow if a person becomes very anemic and needs enhanced red blood cell productionSlide33

Bone StructureMicroscopic AnatomySlide34

Microscopic Structure of Compact BoneHaversian system, or osteon

the structural unit of compact boneSlide35

Microscopic Structure of Compact BoneEach osteon is a group of hollow tubes of bone matrix, called lamella, each one placed outside the nextSlide36

Microscopic Structure of Compact BoneEach osteon is oriented parallel to the long axis of the boneSlide37

Microscopic Structure of Compact BoneOsteons are like tiny weight-bearing pillarsSlide38

Microscopic Structure of Compact BoneLamellaThe weight-bearing, column—like matrix tubes composed mainly of collagenSlide39

Microscopic Structure of Compact BoneHaversian, or central canal channel in the center of the osteoncontaining blood vessels and nervesSlide40

Microscopic Structure of Compact BoneVolkmann’s canals channels lying at right angles to the central canal, connecting blood and nerve supply of the

periosteum

to that of the central canalSlide41

Microscopic Structure of Bone: Compact BoneOsteocytes Mature bone cellsSpider-shaped

Lacunae

small cavities in bone that contain

osteocytesSlide42

Microscopic Structure of Bone: Compact BoneCanaliculi Tiny, hair-like canalsconnect lacunae to each other and the central canal

Forms a transport systemSlide43

Microscopic Structure of Compact BoneFigure 6.6a, bSlide44

Chemical Composition of BoneOrganic components and inorganic componentsSlide45

Chemical Composition of Bone: OrganicOsteoblasts – bone-forming cellsOsteocytes

– mature bone cells

Osteoclasts

– large cells that

resorb

or break down bone matrix

Osteoid

–

unmineralized

bone matrix composed of

proteoglycans

,

glycoproteins

, and collagenSlide46

Chemical Composition of Bone: InorganicHydroxyapatites, or mineral saltsSixty-five percent of bone by mass

Mainly calcium phosphates

Responsible for bone hardness and its resistance to compressionSlide47

Chemical Composition of Bone: InorganicHydroxyapatites, or mineral saltsBone is half as strong as steel in resisting compression and fully as strong as steel in resisting tension

Bones last long after death, sometimes many centuriesSlide48

Paris catacombs Slide49

Study Guide

Pages 123 to top of 126

Quiz

Next Time!