Connective Tissue Flashcards
Embryonic connective tissue
Mesenchyme 2. Mucous
Adult Connective Tissue
- Connective Tissue Proper a. Loose (Areolar) b. Reticular c. Dense Regular d. Dense Irregular
e. Adipose 2. Specialized a. Blood
b. Supporting Connective Tissue
1) Cartilage 2) Bone
Functions of connective tissue
Binds, supports, strengthens – incredibly abundant. Protection, insulation, compartmentalization, transport, storage of energy reserves, immune responses.
Protection
Bone tissue protects brain for example, adipose protects organs, etc.
Compartmentalization
Sections organs and body
Storage of Energy Reserves
Adipose tissue
Immune responses
Blood - white blood cells in particular.
Common characteristics of connective tissue
Incredibly diverse tissue - share the presence of cells in an extracellular matrix, common origin, varying degrees of vascularity.
General Composition of Connective Tissue
Cells (make ground substance) and ECM
ECM
Protein Fibers a. Collagen b. Reticular c. Elastic 2. Ground Substance
a. Glycosaminoglycans (GAGs) (ex. hyaluronic acid and chondroitin sulfate) b. Proteoglycans c. Multiadhesive Glycoproteins (ex. laminin and fibronectin)
Fibroblast, chondroblast, osteoblast, odontoblast
Production of fibers and ground substance-Structural
Mesenchyme
Loosely organized embryonic connective tissue. Has undifferentiated elongated mesenchymal (stem) cells. These cells have an oval nucleus usually, fine chromatin. Have cytoplasmic processes. Brown substances between cells is very viscous. Source of all connective tissues.
Plasma cell
Production of antibodies - Immunologic
Lymphocyte
Production of immunocompetentcells - Immunologic
Eosinophil
Participation in allergic and vasoactive reactions, modulation of mast cell activities and the inflammatory process - Immunologic
Neutrophil
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
Mesenchymal stem cells
Can also differentiate into muscle and epithelial tissue.
Mast cell, Basophil
Liberation of pharmacologically active molecules (e.g., histamine) - defense
Adipose cell - adipocytes
Storage of neutral fats and thermogenesis - Energy reservoir, heat production. From mesenchymal cells. One of the largest cells in body, fat droplet is directly exposed to cytoplasm.
Three Types of Fibers
Collagen – collagen protein 2. Reticular – collagen protein 3. Elastic – elastin protein
EC Matrix
Protein fibers + ground substance. These are secreted by some of the cells.
Collagen
Most abundant protein in human body - 30% of dry body weight. Polymerize into fibers/fibrils. Over 20 types of collagen proteins. Resistant to pulling forces, still flexible (see dermis of skin). In bone, cartilage, tendons, ligaments.
Elastic
Create networks. These are very strong and can be stretchted to 150% of their original length w/o breaking (and can return to shape). Found in skin, blood vessels, lungs, etc.
Reticular
Similar to other collagen fibers, but much thinner, found in networks 0.5-2 microm in width. Provide a lot of framework and structure for other cells. Problem, as these don’t stain with others. Use silver stain to stain them black. Main connective tissue associated with lymphatic system. Lymphocytes hang off of it.
Ground substance
Provides medium through which nutrients, proteins and other substances may diffuse. Can be fluid, semifluid, gelatinous or calcified (no diffusion). Very hydrophilic, binds water and is thus able to be easily compressed (can withstand forces).