Pathology of Inflammatory Responses Flashcards
What are the predominant cell types involved in acute inflammation?
Neutrophils
What are the predominant cell types involved in chronic inflammation?
Macrophages
Lymphocytes
Neutrophils
Define the term “exudate”. What are the two main types?
Fluid rich in protein and/or cells. Two types: Purulent and Fibrinous exudates
Define the term “oedema”
Excess fluid in the extravascular space and body cavities
What is a “transudate”?
An extravascular fluid with low protein content and low specific gravity
Describe the sequence of the events in acute inflammation
- A pathogen binds to Complement C3
- Activation of the Complement cascade
- Release of Histamine and chemo-attractants
- Altered permeability of local vasculature allows fluid exudation (oedema)
- Altered adhesiveness of endothelium allows cellular migration (extravasation by diapedesis)
- Phagocyte recognition of C3b-opsonised pathogen
Define “diapedesis”
The passage of blood cells through the intact walls of the capillaries
State some cell-derived chemical mediators of inflammation
- Cytokines and growth factors
- Nitric Oxide
- Oxygen radicals
- Vasoactive amines
- Arachidonic acid derivates
- Platelet activating factors
- Lysosomal enzymes
State some plasma-derived chemical mediators of inflammation
- Complement system
- Kinin system
- Coagulation & fibrinolytic system
What is a pyrogen?
A substance which resets the temperature control system in the hypothalamus to cause a fever
Give an example of an Exogenous Pyrogen
Lipopolysaccharide (LPS)
Give an example of two Endogenous Pyrogens
IL-1 and IL-6
What is meant by when lungs are “Consolidated” in a Strep pneumoniae infection?
Neutrophils and red blood cells enter alveoli, fluid and cells spread to adjacent alveoli leading to solidification
What is meant by when lungs have undergone “Grey Hepatization” in a Strep pneumoniae infection?
Macrophage recruitment to eat dead neutrophils and digest fibrin mesh occurs
Describe what the structure of an abscess is like?
A core of acute neutrophils often surrounded by chronic inflammatory cells
