Article Figures & Tables
Figures
- Fig. 1.
Arterial oxygen and carbon dioxide content in hooded and grey seals during forced dives. The forced dives were of up to 17 min duration in a bathtub; upper panel: oxygen; lower panel: carbon dioxide; red symbols, hooded seals; blue symbols, grey seals. Redrawn from Scholander (1940).
- Fig. 2.
Mass-specific total available oxygen stores for a variety of adult seals and man, with relative distribution in muscle, blood and lungs. Oxygen measured in ml O2 kg−1; SL, sea lion; FS, fur seal. Redrawn from Burns et al. (2007).
- Fig. 3.
Scanning electron micrograph of the dense aggregate of red blood cells in the dilated spleen of the hooded seal. Scale: each division is 10 µm. From Cabanac et al. (1999).
- Fig. 4.
Myoglobin has a much higher affinity for oxygen than hemoglobin. Hemoglobin (Hb) with four heme groups has sigmoidal oxygen dissociation curves, whereas myoglobin (Mb) with only one has a hyperbolic dissociation curve and a much higher affinity for oxygen, which implies a one-way flow of oxygen from the blood to the skeletal muscles.
- Fig. 5.
Arterial oxygen, carbon dioxide and lactate content in a grey seal before, during and after an 18 min dive. Red trace, oxygen; blue trace, carbon dioxide; yellow trace, lactate (LA). Redrawn from Scholander (1940).
- Fig. 6.
Angiogram of peripheral (abdominal) arteries of a harbour seal. (A) During breathing at the surface, arteries of flanks (thin arrow) and hindflippers (thick arrow) are well filled with blood. (B) During diving, the same arteries become profoundly constricted. Also shown is the bladder (‘B’) in which the contrast medium ends up. Figure from Bron et al. (1966).
- Fig. 7.
First recording of blood pressure in the femoral artery of a seal, at intervals, during an 8 min dive demonstrating dramatic bradycardia and a fairly well maintained central arterial blood pressure. Blood pressure measured in mmHg. Figure from Irving et al. (1942).
- Fig. 8.
Tissue blood flow in the organs indicated after 5 and 10 min of submersion in spotted and grey seals. These two species are not significantly different; brain blood flow is increased, whereas most other organs are more or less excluded from circulation at the end of long experimental dives. Blood flow was measured by use of radioactive microspheres as % of pre-dive flow; red bars, 5 min of submersion; blue bars, 10 min of submersion. Redrawn from Blix et al. (1983).
- Fig. 9.
Voluntary diving in Weddell seals. Peak arterial lactate concentrations upon emergence from dives of various durations (yellow), and the recovery time required at the surface after dives of various durations (blue). Redrawn from Kooyman et al. (1980).
Article navigation
- Top
- Article
- ABSTRACT
- Introduction
- The problem
- The solution
- Oxygen stores
- Simulated diving in the laboratory
- Kidney function during diving
- Skeletal muscle metabolism and buffering capacity
- Selective distribution of cardiac output
- Venous circulation in seals
- Integration of cardiovascular and respiratory responses
- Metabolism during diving
- Unrestrained diving at sea: facts and fiction
- Aerobic dive limit: use and abuse
- Concluding remarks
- Acknowledgements
- FOOTNOTES
- References
- Figures & tables
- Info & metrics
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