Accession Number : ADA290919

Title :   Cardiovascular Control During Stimulated Hypergravity.

Descriptive Note : Final rept. 30 Sep 93-29 Sep 94,

Corporate Author : LEEDS UNIV (UNITED KINGDOM)

Personal Author(s) : Hainsworth, Roger

PDF Url : ADA290919

Report Date : 22 DEC 1994

Pagination or Media Count : 9

Abstract : A model of the circulation was developed using anesthetized dogs which allowed blood pressures and flows at different levels of the body to be changed in ways that simulated the events occurring during acceleration. In particular the responses were examined to decreases in pressure to the carotid baroreceptors and increases in pressure in the splanchnic circulation, changes that would occur during + Gz acceleration. Splanchnic congestion was found to elicit reflex vasoconstriction in the splanchnic. circulation itself as well as in the hind-limbs. There was an interaction between the effects of splanchnic distension and the carotid baroreceptor reflex resulting in nearly a doubling of the gain of the baroreflex. This research has defined a previously unknown mechanism which is likely to be of considerable importance in the maintenance of blood pressure during acceleration and could be of relevance to optimizing counter-G protection.

Descriptors :   *CARDIOVASCULAR SYSTEM, *ANTIMALARIALS, *BLOOD PRESSURE, MAINTENANCE, CONTROL, MODELS, ACCELERATION, CONGESTION, CIRCULATION, SENSE ORGANS, ANESTHESIA, DOGS, REFLEXES, CAROTID ARTERIES, VASOCONSTRICTING.

Subject Categories : Pharmacology
      Anatomy and Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE