Progressive Types Of Cell Injury & Response
Investigating disease includes collating a clinical history, examination, offering a provisional diagnosis and providing a confirmation of diagnosis via diagnostic or lab investigation.Cell injury can be caused by:
- Physical trauma
- Extreme temperatures
- Electrical disturbance
- Chemical or radiation poisoning
- Biological agents
- Nutritional issues
Hypoxia conditions can include:
- Stroke
- Brain trauma
- Arteriosclerosis
- Injury leading to hypoxia
- A decrease in ATP production
- An increase in sodium and H2O into cells
- An increase in potassium outside the cell
- Increased osmotic pressure
- Vacuoles formed
- Increased vaculation
- Increased hydropic degradation
Progressive types of cell injury and response
Cellular adaptation - atrophy, hypertrophy, hyperplasia and metaplasia
Active cell injury - immediate response of the cell
Reversible - decreased ATP, oedema, detachment of ribosomes, autophagy of lysosomes
Irreversible- severe vasculation, Calcium moved into the cell, mitochondrial damage
Apoptosis - normal pathological programmed cell death
Chronic cell injury- subcellular alterations
Accumulations - H2O, pigments, lipids, glycogen and proteins
Pathological calcification- dystrophic and metastatic calcification
Inflammation - a reaction of vascularized tissue to local injury
Non-specific - a defence response of the body, response to tissue damage
1st line of defence - skin, epithelial cells of the GI tract
2nd line of defence - inflammation
Types of necrosis
Necrosis involves oedema and breakdown of organelles including tissue damage via lysosomal enzymes
Coagulative necrosis - tissue appears swollen and firm, no autolysis
Coagulative necrosis - tissue appears swollen and firm, no autolysis
Liquefaction necrosis - neurons rich in hydrologic enzymes
Casseous necrosis - tuberculosis and granulomas
Vascular defence sequence
- Immediately there are pattern recognition receptors
- Mast cells
- Granulocytes (neutrophils, eosinophils, basophils)
- Monocytes/ macrophages
- NK cells
- Platelets
- Endothelial cells
- No memory involved
- Peptides (complement, clotting factors and kinins)
- Four physical symptoms (redness and heat due to hyperaemia, increased blood flow, pain due to chemicals (bradykinin), nerve pressure and damage and swelling due to increased capillary permeability and filtration
3 basic stages of inflammation
- Vascular response,
- Emigration of phagocytes from blood to interstitial fluid &
- Tissue repair
Vascular Response
- Changes that occur in the region of tissue injury include:
- Blood vessel dilation
- Increased permeability in capillaries
- Increased blood flow to remove toxin and dead cells
- Adherence of white blood cells to inner walls of blood vessels
- Immediate
- Swelling
- Plasma moves out and blood flow slows as blood increases in viscosity
- Increased blood flow and RBC count leading to redness
- WBC adhere to capillary walls, biochemical mediators e.g histamine stimulates endothelial cells to retract and more plasma enters leading to swelling.
What substances are involved?
- Histamine (basophils, platelets and mast cells)
- Neutrophils attracted to injured site stimulates release of histamine kinins
- Prostaglandins (lipids are released from damaged cells)
- Leukotrienes
- Result in vasodilation and increased
Comments
Post a Comment