VII: Pulmonary vs Systemic Circulation Flashcards
Why is pulmonary circulation considered a low-pressure system
Right ventricle pressure is less powerful than Left ventricle
Pulmonary vessels are capacitance vessels instead of pressure vessels
Pulmonary circulation is at the level of the heart so there is no compensation for gravity
What are capacitance vessels
Vessels that facilitate blood return to the heart
How much blood reservoire in pulmonary circulation
10%
What enzyme is presented in lung
ACE that synthesized angiotensin II from angiotensin I
Action of lung against thrombi
It is a filter against them
Protects the brain by crushing them
Metabolic functions of the lung
Has DPFC which is a main surfactant component
Surfactant avoids what pathology
Pulmonary edema
Interstitial and capillary hydrostatic pressures causing outflow from capillaries
Interstitial pressure = -8mmHg
Alveolar capillary hydrostatic pressure = 7mmHg
So there is an outflow from the capillary to the lymphs
Consequence of lymphatic vessels saturation
Accumulation of fluid in interstitial spaces
Consequence of accummulation in interstitial spaces
Interstitial edema that can reach the alveolus (Alveolar edema)
πc is
Capillary oncotic pressure
Pch is
Capillary hydrostatic pressure
∏i is
Interstitial oncotic pressure
Decreased πc from
Less protein intake (Hypoproteinemia)
Capillary oncotic pressure
Increased Pch
Capillary hydrostatic pressure
Favors outflow of capillaries –> pulmonayry edema
Pathology causing pulmonary edema
Cardiac pathologies from blood resisting to leave the lung –> increase in pulmonary CAPILLARY pressure
So lymph cannot drain all blood and it accumulates in interstitium
Interstitial edema –> can lead to alveolar edema
Definition of edema
Swelling of tissue
Increase in πi
Interstitial oncotic pressure
Caused by increased capillary permeability (pneumonia)
Alterations in surface tension lead to
Alveoli collapse
Oncotic pressure definition
Forces that pushes fluids INTO blood capillaries
Hydrostatic pressure definition
Force that pushes fluids OUT of the blood capillaries
What other pathology asides from changes in pressure can cause fluid accummulation in interstitium
Neoplasm (tissue growth) of lung structures that causes alterations in flow of lymphatic vessels, preventing proper drainage
