Accession Number : AD0651405

Title :   FORCES DEFORMING THE RIB CAGE.

Descriptive Note : Interim rept., Feb-Jun 66,

Corporate Author : MILAN UNIV (ITALY) ISTITUTO DI FISIOLOGIA UMANA

Personal Author(s) : Agostoni,E. ; Mognoni,P. ; Torri,G. ; Miserocchi,G.

Report Date : FEB 1967

Pagination or Media Count : 18

Abstract : The relaxed rib cage was squeezed along the lateral diameter at different lung volumes with closed airways. The force applied, the decrease of the lateral diameter, the increase of the dorsoventral diameter, and the esophageal and gastric pressures were measured. During a 10-kg. squeeze the increase of the esophageal pressure is negligible, notwithstanding the decrease of the rib-cage cross section and the lack of muscle contraction. The diaphragm is lowered, probably through the lowering of the ribs. A marked decrease of the rib-cage size without a parallel change of the esophageal pressure occurs also when shifting from sitting to standing at functional residual capacity. The work done by the equipment to reduce the lateral diameter as much as during expiratory efforts is about one-third the compressive work done by the muscles during maximum static efforts performed at functional residual capacity and at 60% of the vital capacity. During the breathing cycle the deformation work may become appreciable when the flow resistances are high. (Author)

Descriptors :   (*THORAX, DEFORMATION), STRESS(PHYSIOLOGY), RESPIRATION, FORCE(MECHANICS), PRESSURE, ESOPHAGUS, STOMACH, DIAPHRAGMS(ANATOMY), COMPRESSIVE PROPERTIES, LUNG, ITALY

Subject Categories : Anatomy and Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE