Pathology Cheat Sheet
Inflammation in Motion
Acute inflammation for NEET-PG: cardinal signs, vascular permeability, neutrophils, selectins and integrins, histamine, prostaglandins, and complement.
MedNext Academy | 3 min read
Inflammation in Motion
Acute inflammation for NEET-PG: cardinal signs, vascular permeability, neutrophils, selectins and integrins, histamine, prostaglandins, and complement.
The vascular and cellular events of acute inflammation and the chemical mediators that drive them.
High-yield lines
- The five cardinal signs of inflammation are redness, heat, swelling, pain, and loss of function.
- Vascular events begin with transient vasoconstriction, then vasodilatation causing increased flow, and increased vascular permeability causing exudate.
- Increased vascular permeability is chiefly due to endothelial contraction in venules mediated by histamine, bradykinin, and leukotrienes.
- Neutrophils are the first leukocytes recruited in acute inflammation, typically dominating in the first 24 hours.
- Leukocyte extravasation proceeds through margination, rolling, adhesion, and transmigration.
- Selectins mediate rolling while integrins binding ICAM-1 mediate firm adhesion of leukocytes.
- Histamine from mast cells is the principal mediator of the immediate transient permeability response.
- Arachidonic acid gives rise to prostaglandins via cyclooxygenase and to leukotrienes via lipoxygenase.
- Leukotriene B4 is a potent chemoattractant while leukotrienes C4, D4, and E4 cause bronchospasm and increased permeability.
- The complement products C3a and C5a are anaphylatoxins, and C5a is also a strong chemotactic factor.
- Bradykinin, generated by the kinin system, causes pain, vasodilatation, and increased permeability.
- Exudate is protein-rich fluid of inflammation with high specific gravity, whereas transudate is protein-poor fluid of altered haemodynamics.
Mapped competency codes
- PA4.1
- PA4.2
Continue into the full chapter
This summary maps to PA4-inflammation.
Frequently Asked Questions
Which cell is the first responder in acute inflammation?
The neutrophil, which predominates in the tissue during the first 24 hours of an acute inflammatory response.
What mediates leukocyte rolling and firm adhesion?
Selectins mediate rolling along the endothelium, while integrins binding endothelial ICAM-1 mediate firm adhesion before transmigration.
How do exudate and transudate differ?
Exudate is protein-rich inflammatory fluid with high specific gravity, whereas transudate is protein-poor fluid resulting from altered hydrostatic or oncotic pressure.
What is the main mediator of the immediate increase in vascular permeability?
Histamine released from mast cells, which causes endothelial contraction in venules and early leakage.
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