| Popis: |
Previous researchers have indicated that birds possess an inelastic arterial tree with a high aortic pulse-wave velocity. The present study establishes the pressure-radius and pressure-volume relationships of thoracic and abdominal aortic segments of chickens and mallards. Each segment was affixed to rigid tubing such that the length could not change. The segment was filled with saline at constant flow by an infusion/withdrawl pump to an intraluminal pressure of 300 mm Hg. The pressure-volume curves for the thoracic segments were sigmoidal with greatest compliance in the physiological pressure range. The abdominal segments were less compliant than thoracic segments. Incremental pulse-wave velocities in the physiological pressure range, calculated from the pressure-volume curves, were similar to those of mammals, i.e., 6 to 10 m/sec. Turkey aortic pulse-wave velocities in the physiological pressure range were calculated from pressure-volume curves in the literature as 8 to 12 m/sec. Thus, the pulse-wave velocities of turkeys, chickens, and ducks are similar to mammals. |
