. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 26 B. W. BELMAN AND J. j. CHILDRESS 0 120 180 240 TIME (mm.) 300 360 FIGURE 7. The effect of lo\v oxygen on blood velocity in the hepatopancreas of a g (wet weight) GiHitlioplmnsiii iinjcus. Blood velocity is shown by the symbol X and oxygen concentration by diamonds. tension were measured in three specimens of (/. iiif/cus. The hepatopancreas in this species is extremely large, occupying almost the entire (approximately 70%) in- terior of the animal with other tissues located next to the exoskeleton. The blood ve
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 26 B. W. BELMAN AND J. j. CHILDRESS 0 120 180 240 TIME (mm.) 300 360 FIGURE 7. The effect of lo\v oxygen on blood velocity in the hepatopancreas of a g (wet weight) GiHitlioplmnsiii iinjcus. Blood velocity is shown by the symbol X and oxygen concentration by diamonds. tension were measured in three specimens of (/. iiif/cus. The hepatopancreas in this species is extremely large, occupying almost the entire (approximately 70%) in- terior of the animal with other tissues located next to the exoskeleton. The blood velocity and pOj are plotted for the duration of an experiment with a g animal in Figure 7. Since the flow-probe tip was in contact with tissue, the absolute velocity recorded in this experiment is probably incorrect. However, the relative change in the velocity of blood flowing through this organ as the pO2 de- creases is of particular interest. In this case, the velocity decreases by no more than 16 per cent after 110 minutes of oxygen less than ml O^/l. In the other two such experiments, the decrease in blood velocity in the hepatopancreas was similar: g animal, 2lc/c ; g animal, 14%. Assuming that the physical dimensions of the circulatory channels within the hepatopancreas do not change, it appears that the decline in cardiac contraction frequency and mean systolic blood velocity are paralleled by a decrease in blood flow through this organ. The absolute decrease in volumetric flow is, due to the complexity of the arterial supply to the liepatopancreas, impossible to calculate. However, again assuming that the dimen- sions of the blood channels do not change, a reduction in blood velocity of from would mean a reduction in total flow of the same relative magnitude. Heart rate and EKG Data on heart rate at different oxygen levels can, of course, be derived from either the pressure-pulses or the blood velocity pulses recorded in those particular experiment
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
