Connective Tissue Flashcards
Functions of Glycocalyx
- Cell to cell recognition
- communication
- intercellular adhesion
Name the 4 Major Tissue of the Body
- Epithelial
- Connective
- Muscle
- Nerve
Mesenchyme
Embryonic Connective Tissue
Connective Tissue Proper
Adult Connective Tissue
Which Connective Tissue is specialized?
- Adipose Tissue
- Blood
- Bone and Cartilage
Fibroblasts (Resident or Migratory cells?)
Resident
Macrophages (Resident or Migratory cells?)
Migratory
Reticular Fibers (Function)
Provide a supporting framework for the cellular constituents of various tissues + organs
Elastic Fibers (Function)
Allow tissues to respond to stretch and distention
*Elasticity is genetically controlled
Ground Substance Contents
Specialized macromolecules (10%)
Water (90%)
Ground Substance Functions
- fill space b/w cells + fibers
- lubrication
- diffusion of water soluble molcules
- path for cell migration
- anchor cells through cell to ECM adhesion
2 Major Classifications of Connective Tissue Proper
- Loose/Areolar CT
- Dense CT (Regular + Irregular)
Loose Connective Tissue Functions
- Diffusion of oxygen/carbon dioxide + nutrients/waste
- Inflammatory + Immune Reactions
- Provides Structural Supoprt
Loose Connective Tissue Characteristics
- Flexible
- Well Vascularized
- Cellular
Dense Regular CT (Arrangement + Functions)
Arrangement: Fibers arranged in orderly parallel bundles
- Transmit force of muscle contraction
- Attach muscles to bones
- Protection (ligaments + cornea)
Dense Irregular CT (Arrangement + Functions)
Arrangement: Fibers arranged randomly
- Provide tensile strength
- Protection
ex) skin and GI tract
How does Connective Tissue provide nutrition?
- Reservoir for water and electrolytes
- Stores energy in the form of triglycerides (adipocytes)
- Support blood vessels
- Passageway for nutrients and gases
Collagen Fiber System Components
Collagen Fibers + Reticular Fibers
Elastic Fiber System Components
Elastic Fibers
What causes scurvy?
Vitamin C deficiency
*Vitamin C is essential for the synthesis of collagen; the matrix produces in scurvy is not calcifiable => bone formation is impaired
Reticular Fibers (Location + Function)
Found in lymphatic organs
Support hematopoietic + lymphoid organs
Elastic Fibers (Location + Function)
Found in walls of large blood vessels + ligaments
Functions: elasticity, resilence + shape control
Desmosine + Isodesmosine Function
Cross-linking elastic fibers (enable their stretch + recoil)
Extracellular Matrix Components
Ground substance + Fibers
Extracellular Matrix Function
Informs cells about the biochemical + mechanical changes in their extracellular environment
Glycosaminoglycans (GAGs)
metabolically cheap bulking agent (acidic -> attract ions (Ex. Na+) -> attracts water => molecule puffs up in gel to fill the space
compressive strength
Hyaluronic Acid (Functions)
- resist compression
- promotes flexibility
- shock absorber
- immobilizes molecules (Ex. growth factors)
- Insulator (Prevents diffusion through the dense network)
Hyaluronic Acid (Location)
Cartilage
Hyaluronic Acid (Characteristics)
- Free carbohydrate chain
-linker proteins help proteoglycans indirectly bind to HA - large, rigid non-sulfated GAG synthesized on cell surface
Hyaluronidases
- enzymes that degrade HA
- lowers the viscosity of CT
- increases tissue permeability
How does the ECM communicate with the contents of the cytoplasm?
multi-adhesive glycoproteins facilitate attachment between Cell - CT element / CT element - CT element
Fibroblasts are precursors of …
… ground substance
… collagen
… elastic fibers
Myofibroblast
specialized fibroblast in the salivary gland
Fibroblast (Structural Features)
- spindle-shaped cells
- elliptic nucleus
- thin cytoplasm
Fibroblast (Functions)
- synthesis and secretion of collagen + elastic precursors, proteoglycans and glycoproteins
Diapedesis
WBC leave blood by migrating b/w the epithelial lining of capillaries to enter
When does diapedesis increase?
inflammation
Signs of inflammation
- redness
- swelling
- heat
- pain
Macrophage (Functions)
- activation and presentation (antigen presentation to lymphocytes by ingesting antigen, chewing and spitting it to MHC II)
- phagocytosis (release cytokines + enzymes that break down GAGs)
Macrophage (Structural Features)
- Lysosomes
- Numerous phagocytic nucleus
- Oval/kidney shaped nucleus
*Dust cells present in lungs of smokers
Mast Cells (Functions)
- Release chemical mediators
- important in allergic responses
Mast Cells (Location)
Origin: Arise from multipotent hematopoietic stem cells in the bone marrow
Oval to round cells with microvilli
Nucleus is centrally located (surface expresses IgE receptors)
Cytoplasm contains dense basophilic secretory granules
Eosinophilic
Plasma Cells (Functions)
Produce single class of antibodies in response to antigen
Plasma Cells (Location)
Concentrated in areas that are more likely to be penetrated by foreign material
Ex. GI tract
Plasma Cells (Structural Features)
- Oval Cell
- Eccentric nucleus
- Golgi Ghost
- Cytoplasm is NOT eosinophilic
