Week 4Tissue
Connective CTL
Tissue Histology I.
(Epithelia & Connective, Muscle, Nervous)
#2. Connective Tissue:
- Found everywhere in the body
- Most abundant primary tissue
- 4 Classes of Connective Tissue: (see latter pages)
o Connective tissue proper
o Cartilage
o Bone
o Blood
- 4 Major Functions:
o Binding / Support
o Protection
o Insulation
o Transportation (blood)
- Common Characteristics:
o Common Origin
§ All arise from mesenchyme (embryonic tissue)
o Degrees of vascularity
§ Avascular (cartilage)
§ Poorly vascular (dense connective tissue)
§ Rich blood supply.
o Largely nonliving:
§ Connective tissue is made up largely of non-living extracellular matrix.
§ Some sparse living cells.
§ Can therefore bear weight, withstand tension, trauma & abrasion.
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, - Structural Elements:
o Extracellular matrix
§ Ground Substance
• Unstructured interstitial (tissue) fluid.
• Cell adhesion proteins (laminin & fibronectin) – allows connective tissue cells
to attach to matrix elements.
• Proteoglycans – trap water, making it more viscous (varying degrees.)
• Functions as a molecular sieve – nutrients diffuse between blood capillaries
and cells.
§ Fibres
• Collagen Fibres (white fibres)
o Constructed of the fibrous protein “Collagen”
o Found in all connective tissues
o Small cross-linked fibrils bundle together into thick collagen fibres.
o Are extremely tough – high tensile strength
• Elastic
o Long, thin fibres forming branching networks
§ Contain a rubberlike protein, elastin.
o Allow for stretch and recoil (skin, lungs, blood-vessels)
• Reticular
o Collagenous fibres that form delicate networks
o Surround blood vessels & support soft tissue of organs.
o Particularly common where connective tissues meet other tissue
types. (basement membrane of epithelial cells)
o Cells
§ Make up connective tissue once matured (blasts = immature, cytes = mature)
§ Fibroblasts – Connective tissue proper
§ Chondroblasts – Cartilage tissue
§ Osteoblast – Bone
§ Hematopoietic Stem cells – Blood
§ White blood cells, plasma cells, macrophages, mast cells.
www.MedStudentNotes.com
Connective CTL
Tissue Histology I.
(Epithelia & Connective, Muscle, Nervous)
#2. Connective Tissue:
- Found everywhere in the body
- Most abundant primary tissue
- 4 Classes of Connective Tissue: (see latter pages)
o Connective tissue proper
o Cartilage
o Bone
o Blood
- 4 Major Functions:
o Binding / Support
o Protection
o Insulation
o Transportation (blood)
- Common Characteristics:
o Common Origin
§ All arise from mesenchyme (embryonic tissue)
o Degrees of vascularity
§ Avascular (cartilage)
§ Poorly vascular (dense connective tissue)
§ Rich blood supply.
o Largely nonliving:
§ Connective tissue is made up largely of non-living extracellular matrix.
§ Some sparse living cells.
§ Can therefore bear weight, withstand tension, trauma & abrasion.
www.MedStudentNotes.com
, - Structural Elements:
o Extracellular matrix
§ Ground Substance
• Unstructured interstitial (tissue) fluid.
• Cell adhesion proteins (laminin & fibronectin) – allows connective tissue cells
to attach to matrix elements.
• Proteoglycans – trap water, making it more viscous (varying degrees.)
• Functions as a molecular sieve – nutrients diffuse between blood capillaries
and cells.
§ Fibres
• Collagen Fibres (white fibres)
o Constructed of the fibrous protein “Collagen”
o Found in all connective tissues
o Small cross-linked fibrils bundle together into thick collagen fibres.
o Are extremely tough – high tensile strength
• Elastic
o Long, thin fibres forming branching networks
§ Contain a rubberlike protein, elastin.
o Allow for stretch and recoil (skin, lungs, blood-vessels)
• Reticular
o Collagenous fibres that form delicate networks
o Surround blood vessels & support soft tissue of organs.
o Particularly common where connective tissues meet other tissue
types. (basement membrane of epithelial cells)
o Cells
§ Make up connective tissue once matured (blasts = immature, cytes = mature)
§ Fibroblasts – Connective tissue proper
§ Chondroblasts – Cartilage tissue
§ Osteoblast – Bone
§ Hematopoietic Stem cells – Blood
§ White blood cells, plasma cells, macrophages, mast cells.
www.MedStudentNotes.com
