Tissue damage, inflammation and repair Flashcards
(23 cards)
Name the 5 physical characteristics of inflammation, and describe how they occur.
- Redness: Dilation of small vessels within damaged area
- Heat: Increased blood flow through region
- Swelling: Accumulation of fluid in extravascular space (Fluid exudate)
- Pain: Stretching and distortion of tissue by increased fluid
- Loss of function: Consciously and reflexively limited by pain. Swelling may also immobilise tissues.
What is necrosis?
Premature cell and living tissue death.
What causes necrosis? (4)
Infections
Toxins
Trauma (extremes of temperature or injury)
Ischemia (Diminished blood supply)-Most common reason
When does necrosis become no longer reversible?
When tissues become infarcted (Blood and oxygen supply become blocked)
What is apoptosis?
The process of programmed cell death.
What is meant by resolution?
The complete restoration of tissues to normal after an episode of acute inflammation.
What are the factors that favour resolution? (4)
- Minimal cell death/tissue damage
- Occurrence in organs/tissue with regenerative capacity
- Rapid destruction of causal agent
- Rapid removal of fluid/debris by good local vascular drainage
What is meant by Healing by regeneration?
Replacing of cells that were originally lost to the point where no visible defects are apparent.
What is meant by Healing by repair?
Healing where tissue has been lost, by the process of fibrosis and scar tissue.
What is suppuration?
The formation of pus
What is pus made up of?
- Living cells (including inflammatory cells)
- Dying cells
- Dead neutrophils
- Cellular debris
- Bacteria
What causes an abcess?
An accumulation of pus within a tissue.
What is organisation of tissues?
Their replacement by granulation tissue.
What is granulation tissue?
Collagen rich tissue that forms at the site of an injury.
What is angiogenesis?
The formation of new blood vessels
What are the predominant features in repair?
- Angiogenesis
- Fibroblast proliferation
- Collagen synthesis (forming scars)
What are the causative agents of acute inflammation? (2)
- Bacterial pathogens
- Injured tissues
What are the causative agents of chronic inflammation? (4)
- Persistent acute inflammation formed by non degradable pathogens
- Viral infection
- Persistent foreign bodies
- Autoimmune reactions
What are the major cells involved in acute inflammation? (5)
- Neutrophils (Primarily)
- Basophils (Inflammatory response)
- Eosinophils (Response to worms and parasites)
- Monocytes
- Macrophages
What are the outcomes of acute inflammation? (3)
Resolution
Abcess formation
Chronic inflammation
What are the major cells involved in chronic inflammation? (5)
Monocytes
Macrophages
Lymphocytes
Plasma cells
Fibroblasts
What are the outcomes of chronic inflammation?
Tissue destruction
Fibrosis
Necrosis
What four factors does loss of cell integrity affect?
- DNA
- Cell membrane
- Energy production
- Protein synthesis
