Pathology Flashcards
What is inflammation
The body’s response to injury or infection using different types of cells
What are the types of inflammation
- Chronic and acute AKA neutrophil-mediated inflammation and macrophages/lymphocyte mediated inflammation
What are neutrophil polymorphs
White blood cells made in the bone marrow with a very short lifespan
What is the rough lifespan of a neutrophil polymorph
2-3 days
Describe the shape of a neutrophil polymorph
Polylobed nucleus
Function of polymorphs
Phagocytose debris and bacteria and kill and digest them using lysosomes
What cell responds first in acute inflammation
Neutrophil polymorphs
What is a macrophage
A type of white blood cell
How do macrophages differ to neutrophils
Macrophages have a longer lifespan than neutrophils
Function of neutrophils
- phagocytose debris and bacteria.
- produce and release pro-inflammatory factors to recruit more immune cells
- They also transport material to lymph nodes and may present the material to lymphocytes so a secondary immune reaction is induced.
Give 3 examples of types of macrophages
- Kupffer cells in liver
- Osteoclasts in bone
- Microglial cells in brain
- Alveolar macrophages
What is a lymphocyte
A type of WBC with long lifespan
Function of lymphocytes
- produce chemicals involved in controlling inflammation and antibodies.
- Immunological memory of the body to scale up an immune response against a previously seen microorganism
Function of a fibroblast
Produce collagenous connective tissue in scarring following some types of inflammation.
What are the 5 cardinal signs of inflammation?
- swelling
- pain
- heat
- loss of function
- redness
Stages of inflammation
- increased vessel permeability inflammatory cytokines mediate vasodilation - e.g. bradykinin, prostacyclin and nitrous oxide
- fluid exudate the vessel becomes leaky and fluid is forced out of the vessel
- cellular exudate neutrophils become abundant in the exudate
Sequence of chronic inflammation
• either progresses from acute inflammation or starts as ‘chronic’ inflammation such as infectious mononucleosis (thus better term is macrophage/lymphocyte-mediated inflammation)
• no or very few neutrophils
• macrophages and lymphocytes, then usually fibroblasts
• can resolve if no tissue damage (e.g. viral infection like glandular fever) but often ends up with repair and formation of scar tissue
What is a granuloma
- particular type of chronic inflammation with collections of macrophages/histiocytes surrounded by lymphocytes
When are granulomas commonly seen?
- MYcobacterial infections
- Tb
- Leprosy
- Chrohns
- sarcoidosis
- may be seen around foreign material in tissues
Broad pattern of acute inflammation
Polymorph neutrophils first then macrophages later.
cells involved in chronic inflammation
• Lymphocytes, plasma cells, macrophages.
• Epithelioid macrophages can sometimes be seen as granulomas
Name five causes of inflammation
- Necrosis
- Infection
- Chemical agents, other physical agents or radiation
- Autoimmune reactions, especially hypersensitivity
- Hypersensitivity reactions
Why does inflammation occur
To bring all the cells needed for healing to the site of inflammation
Name 5 causes of acute inflammation