L3: Congestion, Edema & Haemorrhage Flashcards
What do both hyperemia and congestion indicate?
Both indicate a local increased volume of blood in a particular tissue.
What is the definition of hyperemia?
it is an active process that result from increased blood flow due to arteriolar dilation.
What are the causes of hyperemia?
- Physiological e.g. Muscular Exercise, emotion& exposure to heat
- Pathological e.g. Acute inflammation& fever. “VD to allow the Flow of immune cells”
- The affected tissue is red because of engorgement with oxygenated blood.
What is the definition of congestion?
Is a passive type of hyperemia due to obstructed venous flow of the tissue.
What are the causes of congestion?
( pathologic only )
- Acute congestion - Sudden right sided heart failure. “Leads to stopping of Venus outflow” - Shock.
- Chronic congestion
- Localized….pulmonary congestion in left sided heart failure.
- Generalized….all organs (including liver) in right sided heart failure.
-Affected organ is blue red “lung congestion” in color due to increased non-oxygenated blood.
What is the causes of CVC of the liver? “Generalized”
right-sided heart failure.
What are the pathogenesis of CVC of the liver?
During the early stages:
- The central part of hepatic lobule is affected with dilated central vein “due to blood” “from hepatic artery” and adjacent blood sinusoids “from central vein” and appear deep red in color.
- The mid zone of the lobule suffer hypoxia “as the blood is deoxygenated” and shows fatty change and appear yellow in color.
- The alternating red and yellow color resemble the nutmeg seed (nut meg liver).
“Periphery isn’t affected”
During late stages of the disease,
- The central cells become necrotic with destruction of the reticular framework. This area of necrosis will be replaced by fibrosis.
- This is called cardiac cirrhosis.
What are the causes of CVC of the lung? “Localized”
1- Left sided heart failure..
2- Mitral stenosis
What is the pathogenesis of CVC of the lung?
In early stage:
- Congestion and distention “increased hydrostatic pressure” of alveolar capillaries leads to transudation of fluid into alveolar spaces
- Rupture of capillaries leads to passage of RBCs into the alveoli.
- Phagocytosis and degradation of red cells result in intra-alveolar hemosidrin-laden macrophages “due to HB” called Heart failure cells.
- At this stage the lungs are “EHBO”
- Enlarged
- Heavy “Due to transudate and blood”
- Bluish-red in color “deoxygenated”
- C/S oozes bloody froth. “Bubbles of air”
In late stage:
-Fibrosis of interstitium & hemosidrin deposition results in Brown induration “fibrosis” of the lung.
- At this stage the lung appears *dark brown
- firm consistency (indurated) due to associated fibrosis.
What is the definition of edema?
- Pathological accumulation of excess fluids in the interstitial tissue spaces or body cavities “pleura, peritonitis and pericardium”
where does fluid accumulates in case of edema?
Fluid is outside cells and outside vascular structures
What is the pathogenesis of edema? “Inc filtration or dec Absorbtion or problem in lymphatics”
- Increased intravascular hydrostatic pressure: due to venous obstruction “congestion”
- Decreased plasma oncotic pressure:
A)Decrease protein synthesis as in liver disease
b) Protein loss as in renal disease - Lymphatic obstruction: due “to SC 4I”
a) Congenital absence of the lymphatics.
b) Surgical removal of LNs. “Edema at that place”
c) Infection: Filariasis.
d) Tumor infiltration. “Obstruction”
e) Irradiation.
f) Inflammation (lymphangitis) - Increased vascular permeability as in acute inflammation
- Sodium retention as in impaired renal function.
What is edema classified according to?
1- According to the site of edema
2- According to consistency of edema
3- According to edema fluid
What are the types of edema according to the site?
1- Localized edema
2- Generalized edema (anasarca) “central affection”
What are types of local edema?
Inflammatory “exudate”
obstructive (Venous “transudate” or lymphatic “lymph” ) (lymphedema)
What are the types of generalized edema?
Cardiac, renal, hepatic and nutritional (hypoproteinemia) “low protein which decreases oncotic pressure”
What are the types of edema according to consistency?
1- Pitting edema: When pressure is applied to an area of edema a depression or dent results as excessive interstitial fluid is forced to adjacent areas.
2- Non-Pitting edema .
