. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. RESPIRATION IN SCYLLIUM CANICULA 181 to prevent any possible blood pressure effects through changes in water pressure on the gill FIG. 1. Reflex cardiac and respiratory responses. In this and in subsequent figures the upper tracing is a record of the heart beat. The middle tracing records respiration. The large divisions on the time-signal record are ten seconds. A, perfusion of the gills suddenly stopped and started. B, flow of perfusion water quickly increased and decreased. When the rate of flow was changed gent
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. RESPIRATION IN SCYLLIUM CANICULA 181 to prevent any possible blood pressure effects through changes in water pressure on the gill FIG. 1. Reflex cardiac and respiratory responses. In this and in subsequent figures the upper tracing is a record of the heart beat. The middle tracing records respiration. The large divisions on the time-signal record are ten seconds. A, perfusion of the gills suddenly stopped and started. B, flow of perfusion water quickly increased and decreased. When the rate of flow was changed gently from 200 cc. per minute to 400 cc., there was an increase in both respiration rate and heart rate. If the flow was then reduced to the original, there was a return to the previous heart and respiratory rates (Fig. 2). In this case the heart rate before the change was 25 per minute, and the respiratory rate was 21. During a flow of 400 cc. per minute they were 42 and 27, respectively. A return to 200 cc. per minute gave 22 and 21, and a second increase to 400 cc. resulted in a heart rate of 42 and a respiratory rate of 31. Too great an increase, however, produced an irregularly inhibited rhythm of both the heart and the respiration. When the flow of water was stopped for a period of several minutes, there was usually a temporary inhibition of both respiration and heart, followed by a slower rhythm which was sometimes very regular (Fig. 3) and sometimes showed a tendency toward periodicity (Fig. 4). With further continued lack of water the regularity of respiration was interrupted from time to time by generalized reflex muscular responses from the remaining parts of the central nervous system, during which both respiration and heart were irregularly inhibited. The medullary centers remained reflexly functional for over three and one-half hours. The immediate result of transection of the aorta at the conus arteriosus was inhibition of both respiration and heart. But in a minute
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
