acute inflammation Flashcards
What is inflammation?
Inflammation is a normal part of immunity, a response to tissue injury aimed to attack and remove the cause of injury and repair damaged tissue. It is self-limiting and beneficial.
What are the stages of inflammatory damage?
- Tissue injury releases chemical signals like histamines.
- Dilation and increased leakiness of capillaries allow phagocytes to migrate to the area.
- Phagocytes consume bacteria and debris, while platelets seal wounded areas.
What are some examples of inflammatory diseases?
Examples include arthritis, bronchitis, colitis, dermatitis, gastritis, hepatitis, nephritis, and psoriasis. -itis ending is all inflammatory diseases
What are the cardinal signs of inflammation?
The cardinal signs are heat, redness, swelling, pain, and loss of function
How do endothelial cells contribute to inflammation?
Endothelial cells line blood vessels, regulate blood flow, and produce nitric oxide (NO), which causes vasodilation, leading to increased blood flow and redness at inflamed sites.
How does oedema occur during inflammation?
Oedema occurs when fluid leaks from blood vessels into tissues, often due to increased vascular permeability caused by molecules like LTC4, LTD4, and LTB4.
What is the role of LTB4 in chemotaxis?
LTB4 is a potent chemotactic agent that attracts inflammatory cells, particularly neutrophils, to the site of inflammation.
What is the role of prostaglandins in inflammation?
Prostaglandins are involved in vasodilation, pain, fever, and they act as targets for anti-inflammatory medications like aspirin and ibuprofen.
How does histamine affect inflammation
Histamine is released from mast cells, basophils, and platelets. It causes vasodilation and increases the permeability of blood vessels, contributing to pain and swelling.
Why is inflammation beneficial?
Inflammation increases the supply of cells and mediators to the site of injury, helping to remove damaged tissue and infectious agents while also providing materials for repair.
What are eicosanoids and their role in inflammation?
Eicosanoids are oxidation products of fatty acids with both pro- and anti-inflammatory actions. Prostaglandins, a type of eicosanoid, play a role in vasodilation, pain, and fever.
What is the role of PGE2 in fever?
PGE2 acts in the hypothalamus to elevate the body’s ‘thermostat,’ leading to an increased metabolism and heat production, which results in fever.
What are the roles of tissue mast cells in inflammation?
Tissue mast cells, similar to circulating basophils, are widely distributed throughout connective tissue and mucosal surfaces. They release inflammatory mediators in response to stimuli such as mechanical injury, allergic reactions (IgE), or chemicals like insect bites.
How does nitric oxide (NO) contribute to the acute inflammatory response?
Nitric oxide (NO), produced by endothelial cells, causes vasodilation, which increases blood flow to the affected area, contributing to the redness and heat characteristic of inflammation.
What are the roles of leukotrienes in oedema and chemotaxis?
LTC4 and LTD4 increase vascular permeability (leading to oedema) without involving neutrophils. LTB4 increases vascular permeability through neutrophil involvement and acts as a potent chemotactic agent, attracting immune cells to the site of inflammation.
What is the significance of endothelial contraction during inflammation?
Endothelial contraction in venules leads to increased permeability, allowing plasma and immune cells to leak into surrounding tissues, contributing to swelling during inflammation.
What is plasma extravasation and how does it occur?
Plasma extravasation is the leakage of plasma from blood vessels into tissues, which causes swelling. It occurs due to increased vascular permeability during inflammation, often triggered by chemical mediators like histamine and leukotrienes.
What role do prostaglandins play in fever during inflammation?
Prostaglandins, particularly PGE2, act on the hypothalamus to raise the body’s temperature set point, leading to fever. This fever helps protect against infection by increasing metabolic activity and immune response.
How do chemical mediators contribute to inflammation
Chemical mediators such as histamine, prostaglandins, and leukotrienes are released by cells and tissues during inflammation. They increase blood flow, vascular permeability, and attract immune cells to the site of injury or infection.
How is the inflammatory response self-limiting?
The inflammatory response is self-limiting because it is designed to resolve once the injury or infection is removed. Mechanisms like the removal of inflammatory stimuli and the release of anti-inflammatory signals help stop inflammation and promote tissue repair.
What is the difference between acute and chronic inflammation?
Acute inflammation is a short-term response to injury or infection that resolves after the harmful stimulus is removed. Chronic inflammation, on the other hand, is a prolonged, persistent inflammation that leads to tissue remodelling, destruction, and fibrosis (scarring).
What are the effects of endothelial cells on vascular tone during inflammation?
Endothelial cells produce nitric oxide (NO), which causes the relaxation of smooth muscles in blood vessels, leading to vasodilation. This increases blood flow and contributes to redness and heat at the site of inflammation.
How does histamine affect vascular permeability during inflammation?
Histamine, released by mast cells and basophils, causes the contraction of endothelial cells in venules, which increases vascular permeability and allows plasma and immune cells to enter the tissue, contributing to swelling and the inflammatory response.
What are some newly synthesized inflammatory mediators?
Newly synthesized inflammatory mediators include eicosanoids, such as prostaglandins and leukotrienes. They play roles in vasodilation, increased vascular permeability, pain, and attracting immune cells to the site of inflammation.
