Cell injury & Inflammation Flashcards
What certain things can trigger inflimation?
- Foreign Bodies
- Infection
- Ischemia/infarction
- Physical/Chemical Injury
- Immune reactions
What are some of the key components of Acute Inflammation?
- Rapid host response triggering vascular and cellular reactions
- Vasodilation- increased blood flow to sight of injury
- Vascular Permeability- it’s an immediate transient response
Together these mechanisms cause leakage of intracascular fluid into the extravascular spaces
What’s the main aim of Inflimmation:
To recruit leukocytes to an area of damage.
What does the term ‘Margination’ mean in terms of inflimmations?
It is when RBC flow to the centre of vessel lumen and WBC flow peripherally. Causing WBC fall into peripheral flow.
What does term ‘Rolling’ mean in terms of inflimmation?
When increased numbers of WBC roll along the edge of damaged endothelium.
What does the term ‘Adgesion’ mean in relation to inflimmation?
When leukocytes finally stop and adhere to the endothelium. Cytokines secreted by injured cells encourage this.
What does ‘Transmigration’ mean in terms of inflammation?
It’s when leucocytes are encouraged to pass through endothelium to extravascular space.
What are Chemotaxis?
They’re Exogenous bacteria and endogenous substances that attract leukocytes towards the area of injury
Name some leucocyte receptors that recognise foreign micrbes…
- Toll receptors
- G Proteins
- Opsonin receptors
- Cytokine receptors
Which is NOT a leucocyte receptor that detects foreign microbes:
- Toll like receptors
- Na mediated Ion channels
- Opsonin
- Cytokine receptors
Na Mediated Ion Channels are NOT receptors found on leucocytes used to recognise microbes
What does the term PHAGOCYTOSIS mean?
It means when receptors on leucocyte bodies recognise microbes… They can attach themself to the bacteria/damaged cell and engulf them! The Leucocyte kills and degrated the offending agent and removes it’s harmful effect.
Name some characteristics of CHRONIC INFLAMMATION
- It’s caused by persistent infection which are difficult to remove.
- Can be immune mediated when reaction is against the host. (Autoimmune)
- Can be caused by prolonged exposure to toxic agents: Silica, asbestos, lipids (Atherosclerosis)
What are Granulomas? And when do they occur?
It’s the bodys attempt to contain an offending agent it cannot eradicate. Strong Macrophage and T cell activation leading to tissue injury
-occurs in TB - caseating lesions in the lungs
What does FIBROSIS mean?
Thickening/ scarring of tissue. Causing scar formation
What are the clinical signs of Inflammation?
5 Cardinal Signs
- Redness
- Heat
- Swelling
- Pain
- Loss of function
What are some symptoms of inflammation?
- Fever
- Tachy
- Low BP
- Raised WCC
- Raised CRP (C reactive protein- measures amount of inflammation)
- General Malaise
- Weight loss (chronic)
- SEPSIS - large amount of toxins in the body
- SEPTIC SHOCK - cardiovascular failure due to sepsis
Treatments of inflammation???
- NSAIDS
- Anti-histamines
- Steroids
- Targeted biologics against immune response proteins eg. anti TNF
What does Hypertrophy mean in terms of cellular in response to stress?
It means increased size of cells resulting in increased size of the organ.
- Physiologically : body builders
- Pathologically : heart in hypertension
What does Hyperplasia mean in terms of cellular response to stress?
It means increase in cell numbers resulting in a larger organ (hypertrophied)
Can occur alongsied hypertrophy:
-Physiologically : Menstruation
-Pathologically : endometrial hyperplasia if hormone stimulus persists
What does ‘ATROPHY’ mean in relation to cellular response to stress?
It’s the shrinkage of the size of the cell by loss of substance:
- Decresed workload
- Reduced blood supply
- Inadequate nutrition
- loss of hormone stimulation
- Ageing
What does Metaplasia mean in relation to cellular response to stress?
When one cell type is replaced by another adult cell type/
It’s reversible. New type of cell my be more able to withstand stress.
EG- chronic Gastro- oesophageal reflux
Name some causes of cellular injury…
- Hypoxia (low oxygen)
- Ischemia (loss of blood supply)
- Chemical Exposure (cigarette smoke, alcohol, paracetamol)
- Infection
- Radiation
- Lack of Nutrients
- Immunological reaction
- Ageing
What is the difference between APOPTOSIS and NECROSIS
APOPTOSIS: -programmed cell dealth -irreparable damage to the cells DNA/protein or deprived from growth factors -Either Pathological or physiological NECROSIS: -Damage to the membranes allows enzymes to digest the cell -Local Inflammation -Always Pathological
What’s APOPTOSIS?
It’s programmed cell death where the cell degrades it’s own DNA/ proteins resulting in dealth
- Membranes remain intact so no contents leak out .
- Dead cell removed by phagocytosis
Give examples of Physiological Apoptosis…
-embryogenesis
-involution of hormone dependent tissues upon
-hormone deprivation
elimination of cells which have served their purpose
-elimination of potentially harmful self-reactive lymphocytes
Give examples of Pathological Apoptosis…
- DNA damage
- Accumulation of misfolded proteins
- Certain infections
- Pathological atrophy in parenchymal organs after duct obstruction
- Cell death induced by cytotoxic T cells
What are the types of NECROSIS?
- Coagulative Necrosis
- Liquefactive Necrosis
- Caseous Necrosis
- Fat Necrosis
Give examples of why cells might get injured…
- Depletion of ATP,Damage, causing: failure of production of energy, failure of free radical production
- Influx of cancium, causing: activation of enzymes which damage cellular components, can cause apoptosis
- Mitochondrial Damage: failure of production of energy, failure of free radical production
- Oxidative Stress
- Damage to cell membrane can cause:↓ phospholipid synthesis causes↓ATP, oxygen free radicals, lipid breakdown
- DNA Damage: can occur after radiation and may cause apoptosis.
What’s neoplasia?
It’s when a cell has mild DNA damaged which causes a gene mutation which eventually lead to abnormal cells and eventually lead to cancer.
