Intro to Pathology + Defence Cells Flashcards
What is immunology
The study of the immune system
What is pathology
The study of the causes/effects of diseases
What is Aetiology
The cause, set of causes, or manner of causation of a disease or condition
What is morphology
The phenotypic changes associated with a disease
What is pathogenisis
Progressive changes as disease develops
What is sequalae
What happens next? Can involve intervention
Why is immunology and pathology needed
To make the correct diagnosis
To give the correct treatment
To understand systemic diseases
To make appropriate referrals
To advise and educate patients
What is the aetiology, morphology, pathogenesis and sequelae of oral cancer
Aetiology – excessive alcohol/tobacco consumption (increased susceptibility)
Morphology – carcinoma formation
Pathogenesis – Processes of hyperplasia, dysplasia, neoplasia
Sequelae – Radiotherapy, surgery, patient advice
Periodontitis (AMPS)
Aetiology – bacterial origin (plaque)
Morphology – gingival tissue inflammation, tooth loss
Pathogenesis – bacterial protease activity, elevated pro-inflammatory response in gingivae
Sequelae – physical debridement of plaque, removal of infected tissue, patient advice
Rheumatoid Arthritis (AMPS)
Aetiology – Environmental, genetic (hereditary), other diseases
Morphology – Joint inflammation
Pathogenesis – elevated pro-inflammatory response and osteoclast activity, circulating ACPA (antibodies)
Sequelae – NSAIDs, Steroids, treatment of other diseases
What systemic diseases is periodontitis linked to
Diabetes
Rheumatoid Arthritis
Stroke
Alzheimer’s Disease
What is the surgical sieve
The importance of the correct diagnosis
Concept of “surgical sieve” refers to a differential diagnosis in which the clinician must distinguish symptoms of a particular disease or condition from others that present similar clinical features
Being able to distinguish between diseases with some similar symptoms
What are the 4 main organs of the immune system
Thymus
Bone marrow
Lymph nodes
Spleen
What is the largest lymphatic organ in the body
Spleen
Where do T-cells mature
Thymus
What is the yellow tissue in the centre of the bone which makes white blood cells which become lymphocytes
Bone marrow
What is the lymphatic system
The motorway for immune cells to circulate
Links key organs:
-Transports clean fluid back to the blood
-Drains excess fluids from tissues
-Removes ‘debris’ from cells of
body
-Transports fats from digestive system
What are the two branches of the immune system
Innate + adaptive
What is the difference between the two immune systems
Innate - first line of defence
Adaptive - specific and acquired
What is an inflammatory reaction
Reaction aimed to eliminate inciting cause
What can cause an inflammatory response
-invading microorganisms
-particulate materials (e.g. dust, prostheses e.g., denture material)
-altered self cells
-transformed malignant cells (cancer)
What are the stages of inflammation
Initiation – response to harmful agents
Progression – containment of harmful agents
Amplification – modulation of immune response
Resolution – healing (acute inflammation)
What is the failure to resolve inflammation
Chronic inflammation
What are some innate immune cells
monocytes/macrophage
mast cells
neutrophils
NK cells
eosinophils
basophils
Which innate immune cells are lymphoid in origin
Natural Killer cells (NK)
Innate immune cells (ILCs)
Which innate immune cells are myeloid in origin
Mast cells
Monocytes/Macrophages
Dendritic cells
Neutrophils
Eosinophils and Basophils
What is the role of monocytes/macrophages
-Circulate in blood as precursors called monocytes
-Migrate into tissues and differentiate into macrophages
-Early responders to infection or tissue damage
-Long-lived with multiple functions
-Phagocytose and present antigen
How do mast cells act
-Granulocytes
-Early responders to infection or tissue damage
-Migrate from blood and differentiate in tissues (blood precursors not defined)
-Protect against pathogens (particularly parasitic worms)
-Best known for role in allergy
What is the purpose of neutrophils
ARGUABLY MOST IMPORTANT
-Phagocytic granulocytes
-Most numerous/important cells in innate immune responses
-Circulate in blood and move into tissue when required
-Contain numerous granules (intracellular vesicles)
What are NK cells
Large structures with granules
Recognize and kill abnormal cells/tumours/viral infected cells
Important for ‘holding back’ virus infections until adaptive immunity kicks in
What are ILCs
Innate lymphoid cells (ILCs) are non-cytotoxic members of the NK cell family
Three subsets – ILC1, ILC2 and ILC3s
Why do we have Dendritic cells
-Several types of DCs (e.g., Langerhans cells)
-Main role is antigen presentation
-Responsible for bridging innate and adaptive immunity
-Move from tissues to lymph nodes passing on information
-Activate T cell and B cells
What are the adaptive immune defence cells
T cells and B cells
What is the function of T cells
T cells give rise to cellular immunity
Evolved to protect against intracellular microbes and to help B cells responses
Recognize peptides presented by antigen presenting cells through the T Cell Receptor (TCR)
Diversity in TCR (can respond to numerous antigens): T cell repertoire
Checkpoints in place however to ensure T cells only respond to foreign pathogens and not ‘self peptides’
What drives the programming of T cells
DC-T cell interactions
What are the different subsets of T cells
T helper cells (CD4+) function to help support other immune cells to fight threats
-Can be TH1, TH2, TH17, TFH cells
Cytotoxic T cells (CD8+) destroy our own cells which have become infected (usually virus-related)
Regulatory T cells (Tregs) regulate or suppress other cells in the immune system
Which cells form a bridge between the adaptive and innate immune system
Dendritic cells
What are the subsets of B cells
Plasma cells - great big antibody factories
Memory B cells - important to mount a quicker antibody response to any subsequent infections
How do B cells work
-Communicate with T cells
-Have a specific B cell receptor for antigens
-B cells produce antibodies
-B cells are also capable of antigen presentation (to T cells for T cell activation)
