Download - Connective Tissue
Tissue: Connective Tissue
Connective Tissues• Composed of cells & extracellular matrix• Extracellular Matrix : fibers & ground substance)
secreted by cells• Cells rarely touch due to usually large amount of
intercellular material (extracellular matrix)• Consistency varies from liquid or gel to solid• Function is to support, connect, protect and insulate• Good nerve & blood supply except cartilage &
tendons
Types of Connective Tissue Fibers• Collagen (25% of protein in your body)
– tough, resistant to pull, yet pliable – formed from the protein collagen
• Elastin (lungs, blood vessels, ear cartilage)– smaller diameter fibers formed from protein elastin
surrounded by glycoprotein (fibrillin)– can stretch up to 150% of relaxed length and return to
original shape• Reticular (spleen and lymph nodes)
– thin, branched fibers that form framework of organs – formed from protein collagen
Connective Tissue
Found throughout the body; most abundant and widely distributed of the primary tissues.
4 main classes:– Connective tissue proper– Cartilage– Bone– Blood
Cell Type Representative Product or Activity Representativ
e Function
Fibroblast,
chondroblast,
osteoblast,
odontoblast
Production of fibers and ground substance Structural
Plasma cell Production of antibodies Immunologic
(defense)
Lymphocyte
(several types)
Production of immunocompetent cells Immunologic
(defense)
Eosinophilic
leukocyte
Participation in allergic and vasoactive reactions,
modulation of mast cell activities and the
inflammatory process
Immunologic
(defense)
Neutrophilic
leukocyte
Phagocytosis of foreign substances, bacteria Defense
Macrophage Secretion of cytokines and other molecules,
phagocytosis of foreign substances and bacteria,
antigen processing and presentation to other cells
Defense
Mast cell and
basophilic
leukocyte
Liberation of pharmacologically active molecules
(eg, histamine)
Defense
(participate in
allergic
reactions)
Adipocyte Storage of neutral fats Energy
reservoir, heat
production
Connective Tissue Proper: Dense Regular
Fig. 4.7b
Areolar Connective Tissue: Model
Figure 4.8
Connective Tissue Proper: Loose
Connective Tissue Proper: Loose
Reticular Tissue
Connective Tissue: Bone (Osseous Tissue)
Compact Bone
• Osteon = lamellae (rings) of mineralized matrix– calcium & phosphate---give it its hardness – interwoven collagen fibers (and other proteins) provide strength
and flexibility• Osteocytes in spaces (lacunae) in between lamellae• Canaliculi (tiny canals) connect cell to cell
– Central canal contains blood vessels, nerves & a lymphatic vessel
Structure of Long Bone
Microscopic Structure of Bone: Compact Bone
Bone Model
Fig. 6.10a
Fig. 5.23
Fig. 5.23a
Fig. 5.23b
Spongy Bone (Cancellous Bone)Osteocyte in lacuna
Spongy Bone (Cancellous Bone)1. Trabecula 2. Marrow
cavity 3. Adipose
(fat) cell 4.
Hemopoietic cells
5. Osteocyte in lacuna
Connective Tissue: Hyaline Cartilage
Figure 4.9f
Fig. 4.7h
Hundreds of Eyes Staring Back at YOU!
Connective Tissue: Blood