Orthopnea is heart failure develops due to
When a normal individual lies down, the pulmonary blood volume increases by up to 400 mL
When the person stands up this blood is discharged into the general circulation.
This shift is the cause of the decrease in vital capacity in the supine position and is responsible for the occurrence of orthopnea in heart failure.
Reservoir function of pulmonary veins
Reservoir function of leg veins
Reservoir function of pulmonary arteries
Reservoir function of leg arteries