Lecture 12 - Gartner Flashcards
(16 cards)
What is inflammation?
A host response to eliminate altered cells, foreign bodies, microorganisms, and antigens. It is a reaction of the MICROCIRCULTATION characterized by the movement of fluid and cells from the blood into the extravascular compartment.
What was John Hunter the first to formally note that we now consider obvious?
Inflammation is not a disease but a non-specific response to injury that has a salutary effect on its host.
What are the steps in the inflammatory response and of what do they comprise?
Initiation: recognition that injury has occured
Amplification: of humoral and cell mediators
Termination: elimination of the stimulus and ending inflammatory mediators
What is the vascular response and of what is it comprised?
It is the changes in the microcirculation and structure of the vessel wall which lead to:
Vasodilation
Increased blood flow to area
Loss of endothelial integrity
Leakage of fluid and plasma proteins to extravascular space
Emigration of WBCs and RBCs into tissue
What are the cardinal signs of inflammation according to Celsus and to what do they translate now?
Rubor - redness Calor - increase in temp Tumor - swelling Dolor - pain Functio Laesa - loss of function
On what does the difference between acute and chronic inflammation depend?
Persistence of stimulus and nature of response
What would you expect to see in an acute inflammatory response?
Sterotypic
Accumulation of fluid/protein
Activation of platelets
Accumulation of neutrophils
What would you expect to see in a chronic inflammatory response?
Presence of lymphocytes, macrophages, plasma cells, granulation tissue and fibrosis
What is ECF?
Extracellular fluid
Describe starling’s forces.
These can occur during what three processes?
The starling equation illustrates the role of hydrostatic and oncotic forces in the movement of fluid across capillary membranes.
Diffusion, filtration, pinocytosis
How is non-inflammatory edema caused?
Give an example
When formation of extracellular fluid exceeds clearance by lymphatics.
Ex:
Pulmonary edema in CHF
Swelling due to venus thrombosis
Diffuse edema b/c of burn
Lymphedema due to obstruction of lymphatics
Describe congestive heart failure in terms of the Starling equation/principles.
There is an increase in the venous hydrostatic pressure because the heart cannot pump the blood out. This results in an elevation of the central venous pressure (in the jugular by venous distention). The increased central venous pressure is reflected at the level of the venues - i.e. increased venous hydrostatic pressure. When filtered fluid load exceeds capacity of lymphatics to clear excess, it accumulates manifesting as swelling in affected regions - lungs, ankles/legs, abdomen, etc.
Describe the swelling due to venous thrombosis.
Local elevation of venous hydrostatis pressure due to obstruction of venous blood flow. Filtered fluid load exceeds the capacity of the lymphatics to clear it and excess fluid accumulates in affected region - often extremities.
Describe edema due to a decrease in COP (colloid osmotic pressure).
COP can drop from plasma protein loss (nephrotic syndrome) or malnutrition (fails to make sufficient protein - Kwashiorkor). The ability to return filtered fluid back to circulation is diminished.
When filtered fluid load exceeds the capacity of the lymphatics the excess fluid accumulation manifests as swelling throughout the body since all capillary beds are similarly affected.
Briefly describe lymphedema due to obstruction in lymphatics.
Obstruction of the lymphatics causes localized swelling distal to the obstruction because excess filtered ECF cannot be mopped up and returned to the circulation. This can happen during removal of lymph nodes for cancer treatment and results in elephantiasis.
Who was Sir Thomas Lewis, what did he discover, and what does that discovery entail?
He discovered the triple response and also histamine.
The triple response is the white line, flare, and wheal when the skin is subject to injury without puncture.
