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Connective Tissue Characteristics
 Characteristics:
 Most widely distributed tissues
 Most abundant tissue in weight
 Resident Cells are present in stable numbers
 Wandering Cells appear temporarily in response
to injury or infection
 Extracellular matrix
 Non-living material that surrounds living cells
 Tensile Strength – ability to stretch & recoil
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Connective Tissue Functions
 Functions:
 Binds body tissues together
 Supports the body
 Provides protection
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Connective Tissue Cells
 Cell Types:
 Fibroblast “Fiber Builder”
 Most common resident cell
 Large, star-shaped
 Secretes proteins into matrix to make fibers
 Macrophage – “Big Eater”
 Wandering White Blood Cells
 Clear away debris by phagocytosis
 Mast Cells
 Release heparin to prevent blood clotting
 Release histamine in response to allergins
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Extracellular Matrix
 Two main elements
 Ground substance –
 Mostly water ( water reservoir)
 Hyaluronic Acid
 Fibers
 Collagen fibers
 Elastic fibers
 Reticular fibers
 Matrix varies from fluid (blood) to solid (bone)
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Connective Tissue Types
 Bone (osseous tissue)
 Structure
 Rigid Matrix of calcium salts and
collagen fibers
 Osteocytes (bone cells) in lacunae
(cavities) with cytoplasmic processes
in canaliculi (tunnels)
 Arranged in thin, concentric layers
called lamellae
 Osteonic Canal (Haversian)longitudinal tubes containing blood
vessel
 Osteon (Haversian System) – cylindershaped unit of osteocytes & lamellae
around osteonic canal. Many of these
osteons cemented together make up
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bone.
Figure 3.19a
Connective Tissue Types
 Bone (osseous tissue)
 Function
 Framework /Support
 Protection
 Stores Salts
 Forms blood cells
 Location
 Skeletal System
Figure 3.19a
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Connective Tissue
 Cartilage
 Structure
 Chondrocytes – cartilage cells
 Chondrocytes located in lacunae
 Enclosed in perichondrium
 Lacks direct blood supply; diffusion from
perichondrium
 3 Types:
 Hyaline; Elastic; Fibrocartilage
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Connective Tissue Types
 Hyaline cartilage
(Most common cartilage) “milk glass”
 Structure
 Fine collagen fibers
 Rubbery matrix
 Function
 Bone Development
Figure 3.19b
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Connective Tissue Types
 Hyaline cartilage
Location
 ‘Rings’ in respiratory walls
 Ends of bones
 Nose
 Entire fetal skeleton
 Attaches ribs to breastbone
 Forms supporting structure of
larynx/voicebox
Figure 3.19b
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Connective Tissue Types
 Elastic cartilage
 Structure
 Elastic fibers
 Function
 Provides elasticity
 Flexible framework
 Location
 Vocal cords (larynx)
 External ear
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Connective Tissue Types
 Fibrocartilage
 Structure
 Large collagen fibers
 Highly compressible
(tough)
 Function
 Shock absorber
 Location
 Intervertebral disks
 Cushions in knees
Figure 3.19c
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Connective Tissue Types
 Dense Connective Tissue
 Structure
 Closely-packed collagen
fibers
 Few Fibroblasts
 Function and Location
 Tendon – attach muscle to
bone
 Ligaments – attach bone
to bone
Figure 3.19d
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Connective Tissue Types
 Areolar (Loose) C. T.
 Structure
 ‘Areolar’ – small open spaces
 Fibroblasts between elastin & collagen
 Soft, pliable tissue
 Function
 Holds organs in place
 Tissue fluid provides water & salts
 Can soak up excess fluid

Edema- swelling from excess fluid
 Location
 Around organs
 Beneath skin
 Between muscles
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Figure 3.19e
Connective Tissue Types
 Adipose tissue
 Structure
 Form of Loose C.T.
 Fat-filled vacuole occupies cell
 Nucleus pushed to membrane
 Functions
 Insulation
Fuel storage
 Protective cushion
 Location
 Beneath skin
Around kidneys
 Between muscles
Around heart
 Behind eyeballs
Around joints
 Abdominal membranes
Figure 3.19f
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Connective Tissue Types
 Blood
 Structure
 RBC
Platelets
 WBC
Plasma- Fluid matrix
 Function
 Transports materials
 Maintains homeostasis
 Location
 Cardiovascular System
Figure 3.19h
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Muscle Tissue
 Function is to produce movement
 Three types
 Skeletal muscle
 Cardiac muscle
 Smooth muscle
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Muscle Tissue Types
 Skeletal muscle
 Can be controlled
voluntarily
 Cells attach to
connective tissue
 Cells are striated
 Cells have more than
one nucleus
Figure 3.20a
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Muscle Tissue Types
 Cardiac muscle
 Found only in the
heart
 Function is to pump
blood (involuntary)
 Cells attached to
other cardiac muscle
cells at intercalated
disks
 Cells are striated
 One nucleus per cell
Figure 3.20b
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Muscle Tissue Types
 Smooth muscle
 Involuntary muscle
 Surrounds hollow
organs
 Attached to other
smooth muscle cells
 No visible striations
 One nucleus per cell
Figure 3.20c
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Nervous Tissue
 Neurons and nerve
support cells
 Function is to send
impulses to other
areas of the body
 Irritability
 Conductivity
Figure 3.21
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Tissue Repair
 Regeneration
 Replacement of destroyed tissue by the
same kind of cells
 Fibrosis
 Repair by dense fibrous connective tissue
(scar tissue)
 Determination of method
 Type of tissue damaged
 Severity of the injury
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Events in Tissue Repair
 Capillaries become very permeable
 Introduce clotting proteins
 Wall off injured area
 Formation of granulation tissue
 Regeneration of surface epithelium
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Regeneration of Tissues
 Tissues that regenerate easily
 Epithelial tissue
 Fibrous connective tissue and bone
 Tissues that regenerate poorly
 Skeletal muscle
 Tissues that are replaced largely with scar tissue
 Cardiac muscle
 Nervous tissue within the brain and spinal cord
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Developmental Aspects of Tissue
 Epithelial tissue arises from all three primary
germ layers
 Muscle and connective tissue arise from the
mesoderm
 Nervous tissue arises from the ectoderm
 With old age there is a decrease in mass and
viabililty in most tissues
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