Pathology Flashcards
What is the role of the autopsy?
Who was the deceased?
When did they die?
Where did they die?
How did they come about their death?
What is the structure of an autopsy?
- History
- External examination
- Evisceration
- Internal examination
- Reconstruction
Name the three types of death referred to the coroner?
Presumed Natural (Cause not known
Presumed Iatrogenic
(Caused by care or surgery)
Presumed Unnatural
Define acute inflammation
Initial and transient series of tissue reactions to injury of short duration that normally resolves
Define chronic inflammation
Subsequent and prolonged tissue reactions following initial response (Sequel to acute that may never resolve)
What are the 5 cells involved in inflammation?
Neutrophil polymorphs Macrophages Lymphocytes Endothelial cells Fibroblasts
Describe the roles of neutrophil in inflammation
- Short lived - first cells on scene
- Cytoplasmic granules full of bacteria killing enzymes
- Die at the scene of inflammation
- Release chemicals that attract other inflammatory cells (Macrophages)
Describe the role of macrophages in inflammation
- Long lived (Weeks to months)
- Phagocytic
- Ingest bacteria and debris
- May carry debris away
- Present antigens to lymphocytes
Describe the role of lymphocytes in inflammation
- long lived
- Produce chemicals that attract other inflammatory cells
- Immunological memory for past infections and antigens
Describe the role of endothelial cell in inflammation
- Line capillary blood vessels in areas of inflammation
- Become sticky in areas of inflammation so inflammatory cells adhere to them
- Become porous to allow inflammatory cells to pass into tissues
- Grow into areas of damage to form new capillary vessels
Describe the role of fibroblasts in inflammation
Long lived cells that form collagen in areas of chronic inflammation and repair
Name the 6 causes of acute inflammation
- Microbial Infections
- Hypersensitivity reactions
- Physical agents (Trauma, ionising radiation, heat and cold)
- Chemicals (Corrosive, acids, alkalis and reducing agents)
- Bacterial toxins
- Tissue necrosis
Define hypersensitivity Reactions
Reaction which occurs when an altered state of immunological responsiveness causes an inappropriate or excessive immune reaction that damages tissues
What are the 5 characteristic of acute inflammation
- Redness (Dilation of small blood vessels) Rubber
- Heat (Due to increased blood flow) Calor
- Swelling (oedema from accumulation of fluid in the extravascular space) Tumor
- Pain (Due to tissue distortion, pus under pressure in abscess cavity and chemical mediators that induce pain (Bradykinin, serotonin and prostaglandins) Dolor
- Loss of function
Name the three processes involved in the acute inflammatory response
- Change in vessel calibre (width) and increased flow
- precapillary sphincters regulate flow through the capillary bed - Increased vascular permeability and fluid exudate formation
- Formation of cellular exudate due to increased capillary hydrostatic pressure and escape of plasma proteins
Name the 4 outcomes of acute inflammation
1. Resolution = complete restoration of tissue to normal 2. Suppuration = formation of pus 3. Organisation = tissue replaced by granulation tissue 4. Progression to chronic inflammation
What are the 4 causes of chronic inflammation?
- Primary chronic inflammation
- Transplant rejection
- Progression from acute inflammation
- Recurrent episodes of acute inflammation
What are the features of chronic inflammation?
- Cellular infiltrate consists of lymphocytes, plasma cells and macrophages
- Macrophages may form multinucleate giant cells
- Neutrophils are scarce
- Continued tissue destruction - necrosis
What is a granuloma?
Aggregate of epithelioid histiocytes
Name some examples of granulomatous inflammation?
- Tuberculosis
- Leprosy
- Crohns disese
- Sarcoidosis
What causes histolytic giant cells to form?
Accumulation of particulate matter that is indigestible by macrophages
What do fibroblasts produce?
Collagen
Name 6 types of cell that are capable of regeneration
Hepatocytes Pneumocytes All blood cells Gut epithelium Skin epithelium Osteocytes
Name 2 types of cell that do not regenerate
Myocardial cells
Neurones