Hemostasis 2 Flashcards
What does circulation require? (5)
- blood maintained in a fluid state
- appropriate regulation of fluid balance and oncotic pressure
- patent blood vessels
- appropriate vascular tone
- functional pump
What is edema?
increased fluid in the interestitial space
What causes edema? (5)
- increased hydrostatic pressure
- decreased plasma oncotic pressure
- lymphatic obstruction
- salt and water retention
- increased vascular permeability
What is anasarca?
generalized subcutaneous edema
What is ascites?
edema within abdominal sac
What is hydrothorax?
edema within the thoracic cavity
What is hydropericardium?
edema within the pericardial sac
Consequences of edema
- can interfere with organ function (ex: decreased gas exchange in lungs)
- edema within a confined space (ex: brain, pericardial space, etc.)
What is hyperemia?
increased blood flow to a tissue with normal to decreased outflow
(red, warm, firm tissue)
What causes hyperemia?
active process of arteriolar dilation due to exercise, inflammation, and a physiologic mechanism to regulate heat
What is congestion?
local increase in blood volume due to decreased outflow
red/blue, cool, firm tissue
What causes congestion?
decreased outflow
passive process
pathogenesis related to edema
Name the 3 types of congestion
local
pulmonary (inadequate flow from L heart)
generalized (inadequate flow from R heart)
Consequences of congestion (5)
- accumulation of metabolites
- increased hydrostatic pressure (edema)
- decreased arterial blood supply (hypoxia)
- local destruction of endothelium
- chronic congestion can lead to fibrosis
What is ischemia?
deprivation of O2 and substrates for glycolysis due to inadequate perfusion
What causes ischemia?
- localized perfusion deficits due to thromboses
- systemic perfusion deficits due to decreased cardiac output
What is an infarction?
area of peracute ischemia that undergoes necrosis
What causes an infarction?
- often secondary to thrombosis/embolism
- vascular compression or torsion
What is thrombosis?
formation of a thrombus within the vascular lumen
thrombus = aggregate of coagulated blood containing platelets, fibrin, and entrapped cells
What causes thrombosis?
- endothelial injury
- turbulent blood flow
- static blood flow
- hypercoagulability
What is an embolism?
detached intravascular material that is carried by blood and lodges at a distant site
What causes an embolism?
- fragment of thrombus
- fat
- parasites
- neoplastic cells
- fibrocartilage
- bacteria
- air
Consequences of an embolism
- partial obstruction leading to congestion, edema, ischemia
- complete obstruction leading to infarction
