Connective Tissue
Four Basic Kinds of Tissues
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Epithelial Tissue
Connective Tissue
Muscle Tissue
Nervous Tissue
Connective Tissue
Extracellular matrix
Fibroblasts
Collagen Fibers
Reticular Fibers
Elastic Fibers
Connective Tissue
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Most abundant & widely distributed tissue
throughout the body (bones, blood, fat, etc.)
No contact with the outside
Composition:
1. Specialized cells (chondrocytes, macrophages,
melanocytes, adipocytes, lymphocytes, etc.)
2. Extracellular protein fibers
(collagen, reticular, or elastic)
3. Ground substance (often fluid)
Matrix
Functions of Connective Tissue
Functions:
• Establishing a structural framework
• Transporting fluids and dissolved materials
• Protecting delicate organs
• Supporting, surrounding and interconnecting
tissues
• Storing energy reserves
• Defending the body from microorganisms
Classification of Connective Tissues
I. Loose Connective Tissue (support, cushioning)
1. Areolar - cushions organs
2. Reticular - live, spleen
3. Adipose - fat
II. Dense Connective Tissue (fibrous)
1. Dense regular - tendons
2. Dense irregular - white, protective layer of eye
3. Elastic – bronchial tubes, large arteries
III. Cartilage (flexible, strong support)
IV. Bone (structure, support)
V. Liquid Connective Tissue (fluid)
1. Blood (erythrocytes – red blood cells, platelets)
2. Lymph (leukocytes – white blood cells)
Loose & Dense Connective Tissue
• Contains varied cells and fiber types; syrupy ground
substance
Cartilage & Bone
• Dense ground substance & closely packed
fibers
Liquid Connective Tissue
• Watery ground substance with dissolved proteins
Loose Connective Tissue
Dense Connective Tissue
Fig. 4.10
Dense Connective Tissue
Dense Connective Tissue
Cartilage
Most abundant, tough but
flexible
Cartilage
Elastic fibers make cartilage flexible and resilient
Cartilage
Dense collagen fibers make fibrocartilage tough and durable
Bone
Bone has very little substance, strength is due to calcium
salts & collagen fibers
Liquid Connective Tissue
Membranes
• Cover and protect other structures in the body
• Composed of epithelium and connective tissue
• Four types
– Mucous
– Serous
– Cutaneous
– Synovial
Membranes
• Fig. 4.15
• Mucous membranes:
Line cavities that are in
contact with the
exterior; kept moist
• Serous membranes:
Line sealed internal
cavities
• Cutaneous
membranes:
Cover the body surface
(skin)
• Synovial membranes:
Lining within joint
cavities
Practice
Loose connective tissue adipose tissue (fat)
Bone
More Practice
Hyaline cartilage
Liquid connective
tissue - blood
More Practice
Dense irregular
connective tissue –
periosteum (outside of all
bones)
Dense regular
connective tissue tendon
More Practice
Elastic connective tissue between vertebrae
Simple columnar
epithelium – lining of
digestive tract