Lecture 3 Flashcards
When it comes to periodontal disease, what is responsible for nearly all the destruction seen?
(Indirect injury) The host’s response to to antigenic bacterial plaque
When it comes to periodontal disease, the host’s immune system is responsible for nearly all the destruction seen. What does it do to tissue?
Alter tissue and causes irreversible changes in architecture
For disease to develop, what three things need to be present
A causative agent, favorable environment and susceptible host
A diseases onset and severity is determined by
Interaction of host with microorganisms
Bacterial plaque contributes to periodontal breakdown by
Direct injury to tissues
Indirect activation of host inflammatory and immune systems
How does bacterial plaque directly injure tissues?
Caused by bacterial toxins, enzymes and products of metabolism
Bacterial toxins
• Exotoxins
Proteins released by organisms
• Endotoxins - lipopolysaccharides
Cytotoxic agent released from cell wall of gram negative bacteria
Initiate inflammation and cause destruction
Bacterial enzymes facilitate___
Name some bacterial enzymes
Bacterial penetration
• Collagenase
• Hyaluronidase
• Chondroitin sulfatase
• Proteases
• Elastases
How does bacterial plaque indirectly injury tissues?
• Chronic bacterial accumulation results in persistent antigenic stimulus
• Bacterial waste products and toxins are recognized by body as foreign - antigens
• Stimulate a host response: inflammatory and immune systems
• Defense mechanism or response of body against pathogens- Protective
• Same response also causes tissue destruction- Destructive
What explains episodic and site specific nature of disease?
Intensity variation
• Intensity varies from individuals
• Local immune response intensity varies from site to site
• One site with active disease and high levels of inflammatory cells
•Second site with no disease and normal levels of inflammatory cells
Bacterial irritation either indirectly or directly initiates___
The inflammatory response
•a series of protective responses
What is some observable alterations in tissue during an inflammatory response?
Vascular permeability, dilation, infiltration of leukocytes that results in erythema, heat, pain, edema, loss of tissue function
What are the three stages of inflammation?!
Immediate, acute and chronic
What leukocytes control the immediate, acute and chronic stages of inflammation?
Agranulocytes
Granulocytes
Describe acute inflammation from start to finish
- Invasion of pathogens or injury
- Inflammatory cells migrate by chemotaxis (Process of leukocytes to locate and migrate to injury site)
• Neutrophils (PMNs)
• Monocytes → macrophages (histiocyte)
• Lymphocytes (Plasma cells from B lymphocytes) - Aim is to eliminate bacteria
•Phagocytosis: Process by which cells ingest particles of larger size and prevent spread of invading bacteria - If injury minimal and brief and source removed, then tissue undergoes regeneration or repair
Describe chronic inflammation
Injury continues weeks, months or indefinitely
Immune system activated after long duration: next line of defense
Leukocytes seen under inflammation response
Granulocytes: Neutrophils, Basophils, Eosinophils
Agranulocytes: monocytes and lymphocytes
The leukocytes have differing cell counts that can be used in
Detection and monitoring of disease states
Neutrophils
• Polymorphonuclear leukocyte (PMNs)
• Large White Blood Cell
• Most numerous of all WBCs (70%)
• Hallmark of acute inflammation
• Essential for control of bacterial infections
• Responds to chemotactic substances
• Arrive 1st during inflammatory response
• Phagocytosis
•Releases prostaglandin and cytokines during phagocytosis
• Short lived
• Releases destructive enzymes collagenase, elastase, and MMP
Eosinophils
Few in number
Prominent in allergic reactions
Basophils
Increase vascular permeability allow more phagocytic cells to enter into injury site during inflammation
Lymphocytes
Inflammatory response
• Can revert to blast-like cell
• Multiply as immunologic need arises
• Plasma cell
• Seen and most numerous in chronic inflammation;immune response happening in background
Immune response
Primary cell involved in the immune response
Derived from stem cells in bone marrow that migrate to lymphoid tissue/organ then matures
Role is to recognize and respond to antigens
• B lymphocytes
• T lymphocytes
• NK lymphocytes
Monocytes
Inflammatory response
• Large white blood cells
• 2nd cell to participate in inflammatory response
• Phagocytosis function
• Called monocytes in bloodstream but differentiate into macrophages in the tissues
• Seen and most numerous cell in chronic inflammation
•Remain in tissues to repair damages
•Produce destructive enzymes collagenase and MMP
• Produces cytokines and prostaglandins
Immune response
•Macrophages process and present antigens to B-lymphocyte
Macrophages development from
Agranulocytes then monocytes then macrophages