Hypoxic pulmonary vasoconstriction due to
Hypoxic pulmonary vasoconstriction (HPV), also known as the Euler-Liljestrand mechanism, is a physiological phenomenon in which small pulmonary aeries constrict in the presence of alveolar hypoxia (low oxygen levels). Ref Harrison20th edition pg 2334
Irreversible pulmonary vasocontriction hypoxia
Reversible pulmonary vasoconstriction due to hypoxia
Direct blood to poorly ventilated areas
Occurs hours after pulmonary vasoconstriction
C.N.S