Pulmonary circulation differs from systemic circulation: (A) Pulmonary vasodilatation in hypoxia, (B) Pulmonary vasoconstriction in hypoxia, (C) Decreased blood volume during systole, (D) Increased basal vasoconstrictor tone
Answer is B. 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: guyton and hall textbook of medical physiology 12 edition page number: 354,355,356