American journal of veterinary research
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A radiograph technique for identification of diaphragmatic segments and quantitation of their contribution to total diaphragmatic function was developed. five anesthetized ponies were studied on 3 separate occasions. Studies were made of the ponies in left lateral recumbency at 2 anesthetic levels (1 and 2 minimal alveolar anesthetic concentrations; halothane) and under spontaneous and controlled ventilation systems. ⋯ Controlled ventilation altered the pattern of diaphragmatic displacement. Diaphragmatic displacement and regional volume changes were a function of active contraction or passive movement.