W7 - Exercise & Inflammation Flashcards
What are the functions of the inflammatory response?
- Protect against injury and infection
- Initiated when there is physical damage (external objects, unaccustomed exercise)
- Infections (viruses, bacteria, fungal, parasitic)
- Exposure to toxins, pollutants or industrial chemicals, radiation, high levels of FFA
- Stimulate repair of damaged tissues
- Cytokines(signalling molecules, like the hormones of the immune system) and other mediators released from immune cells and damaged
What are the features of acute inflammation?
- immune cells destroy affected cells
- inflammatory proteins stimulate tissue repair
- rapid, short-lived response (mins, days. hours)
Without acute inflammation: would end up with sepsis- Acute = short lasting
What are the features of chronic inflammation?
- Immune cells keep trying to repair
- low level, continuous release of inflammatory proteins
- common causes: unhealthy lifestyle, autoimmune disease
- long-lasting (months, years)
Chronic - is stimulated when the stimulus remains in the blood e.g.: high levels of alcohol- Immune system turns on its own tissues
Low level of pro-inflammatory mediators into the blood, lasts months & years
- Immune system turns on its own tissues
Provide some examples of acute and chronic inflammatory illnesses
Acute:
* Common cold
* A splinter
* Muscle damage - does not lead to any long term health issues
* Radiation exposure
Chronic:
* Obesity
* Autoimmune disease
* Long-term smoking
What are the 5 cardinal signs of acute inflammation?
Heat –> Redness –> Swelling –> Pain –> Loss of Function
Heat happens particularly in the extremities
Redness - from scratching
- Start of 20th century(vechal) - loss of function
Describe each of the cardinal signs:
- Heat & Redness - Increased blood flow due to vascular dilatation gives redness and heat - first 2 to appear
- Swelling - Increased vascular permeability allows fluid and immune cells to move into the damaged area, causing swelling - endothelial cells retract, the cells shrink and this makes the gaps bigger
- Pain - Certain chemical mediators stimulate sensory nerve endings giving pain
- Nerves are also stimulated via stretch receptors due to swelling - can also cause pain
- Pain and swelling result in loss of function
- Protects, to stop further damage being caused
What is the difference between monocytes and macrophages?
- Monocytes will respond the same way no matter the infection
Monocytes - in the blood - Macrophages - in the interstitial fluid and out of the blood(mature tissue version
Of monocytes)
What are granulocytes?
Granulocytes - cytoplasm had granules in it, granules are cytotoxic(killing) enzymes
* Both these cell types are phagocytic (wrap themselves around it to engulf it)
What happens in the acute inflammatory response?
1) Initiation of acute inflammatory response
2) Vascular dilation and increased vascular permeability
3) Margination
4) Neutrophils arrive rapidly
5) phagocytosis of damaged tissue
6) Termination of acute inflammatory response
Describe the first step of: initiation of acute inflammatory response
1) Injury/presence of pathogen
2) LPS & complement proteins
3) recognised by the resident phagocytic immune cells (macrophages & neutrophils)
4) These secrete soluble mediators
e.g.: cytokines, prostaglandins, nitric oxide
Describe step 2: vascular dilation and increased vascular permeability
What is the impact of vascular dilation & increased vascular permeability?
1) activated neutrophils and macrophages
2) These release IL-6 and TNF-a cytokines
3) These cytokines along with Csa activate mast cells
4) the mast cells release: histamine, bradykinin, leukotrienes, PAF, prostaglandins, cytokines
5) bradykinin along with leukotrienes & PAF increase vascular permeability
6) Activated neutrophils and macrophages release prostaglandins, this along with nitric oxide causes vascular dilation
Explain step 3: margination - the process of leukocytes migrating from the blood vessel to tissue
1) Rolling - the neutrophils with adhesion molecules on its surface rolls slowly
2) Tight Binding - These adhesion molecules then stick to the adhesion molecules on the surface of the blood vessel
3) Diapedesis - neutrophils move through the vessel wall via diapedesis into the interstitial space
What is the impact of increased vascular permeability and vascular dilation
1) blood flow increases to the area
2) leakage of fluid into the interstitial space(oedema/swelling)
3) Blood gets thicker - more viscous
4) slow down blood flow
5) clotting leukocyte- margination
What is margination helped by?
explain it
Chemotaxis
* chemically induced movement
* directed migration of cells in response to concentration gradients of secreted cytokines known as ‘chemokines’
* e.g. interleukin‐8 (IL‐8), (potent neutrophil chemokine released by macrophages and mast cells
- Like magnets to move neutrophils into tissues from the blood
Describe step 4: neutrophils arrive rapidly
Main cell recruited in acute inflammation
are neutrophils
- swelling in the local area
