Cont. Skeletal Tissues: Cartilage Skeletal Tissues: …orzo.union.edu/~curreyj/BNG-338_files/Lecture...

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BNG-338: Lecture 7 Cont. Skeletal Tissues: Cartilage Skeletal Tissues: Bone First LBL Presentation on Friday Wednesday, April 15, 15

Transcript of Cont. Skeletal Tissues: Cartilage Skeletal Tissues: …orzo.union.edu/~curreyj/BNG-338_files/Lecture...

BNG-338: Lecture 7

Cont. Skeletal Tissues: Cartilage

Skeletal Tissues: Bone

First LBL Presentation on Friday

Wednesday, April 15, 15

Learning ObjectivesDescribe composition of cartilage and types

Describe composition of bone

Name the types of bone cells and describe their roles

Explain the difference between woven and lamellar bone and when they “appear”

Explain the process of intramembranous ossification

Wednesday, April 15, 15

Skeletal Tissues

Cartilage Bone Tendon and Ligament

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Types of Cartilage

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Hyaline Cartilage

Appears glassy in living tissue

60% to 78% of net weight is water

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Elastic CartilageComposed of same components as hyaline cartilage matrix, plus elastic fibers and interconnecting sheets of elastic material

Surrounded by a perichondrium

does not calcify

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Fibrocartilage

Difficult to distinguish from dense regular connective tissue

Existence of fibrocartilage indicated that the tissue is required to resist compressive and shear forces

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Bone

Specialized connective tissue consisting of a mineralized extracellular matrix with cells residing within this matrix

Mineral contained within the matrix is calcium phosphate in the form of hydroxyapatite crystals

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Hierarchical Structure of

Bone

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The SEM images of collagen/hydroxyapatite composite materials, recorded at different magnification; (a) parallel view with the fibres, (b–c) perpendicular view with the fibres, (d) high resolution SEM at 80,000× magnification.

Ficai, A et al. Chemical Engineering Journal. 160:2: Pages 794-800

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OsteocytesReside in lacunae surrounded by EC fluid

Osteocytes have “arms” that extend into canaliculi and meet processes of other osteocytes

Can pass ions from one cell to another

Believed to be sensors of mechanical load and deformation and can transmit signals to other cells

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Bone Cells

There are 4 types of bone cells:

osteocytes

osteoprogenitor cells (bone lining cells)

osteoblasts

osteoclasts

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Types of BonesLong bones~ longer in one dimension that the other

Short bones~ nearly equal in length and diameter

Flat bones~ thin and plate like

Irregular or sesamoid bones~ shape does not fit into the 3 previous categories

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BoneCortical (Compact) Bone

Porosity of 5-10%

Pores categorized as Haversian canals, Volkmann’s canals, and resorption cavities

Cancellous (Spongy) Bone

Porosity of 75-95%

Pores are filled with Marrow

Made up of trabeculae, 200um thick

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Long Bones

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Bone Continued

Endosteum

Lines marrow cavity and cavities of cortical and cancellous bone

One cell thick which have the capacity to differentiate into osteoblast

Periosteum

Covers outer surface of bone

Contains osteoprogenitor cells

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Lamellar vs Woven Bone

Woven Bone

Lamellar Bone

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Learning Objectives

Describe composition of cartilage and types

Describe composition of bone

Name the types of bone cells and describe their roles

Explain the difference between woven and lamellar bone and when they “appear”

Wednesday, April 15, 15