Blood oxygen transport and depletion : the key of consummate divers
To investigate the physiological enigma of the impressive dives of emperor penguins and elephant seals, blood oxygen (O₂) transport and depletion in these species were addressed with a three tiered approach. First, the transport of O₂ was examined by assessing heart rate (the principal determinant o...
Main Author: | |
---|---|
Format: | Doctoral or Postdoctoral Thesis |
Language: | unknown |
Published: |
eScholarship, University of California
2009
|
Subjects: | |
Online Access: | http://www.escholarship.org/uc/item/7pk7c8sq http://n2t.net/ark:/20775/bb65541938 |
id |
ftcdlib:qt7pk7c8sq |
---|---|
record_format |
openpolar |
spelling |
ftcdlib:qt7pk7c8sq 2023-05-15T16:05:17+02:00 Blood oxygen transport and depletion : the key of consummate divers Meir, Jessica Ulrika 1 PDF (xix, 106 p.) 2009-01-01 application/pdf http://www.escholarship.org/uc/item/7pk7c8sq http://n2t.net/ark:/20775/bb65541938 unknown eScholarship, University of California http://www.escholarship.org/uc/item/7pk7c8sq qt7pk7c8sq http://n2t.net/ark:/20775/bb65541938 public Meir, Jessica Ulrika. (2009). Blood oxygen transport and depletion : the key of consummate divers. UC San Diego: Retrieved from: http://www.escholarship.org/uc/item/7pk7c8sq UCSD Dissertations Academic Marine biology. (Discipline) dissertation 2009 ftcdlib 2016-04-02T18:42:56Z To investigate the physiological enigma of the impressive dives of emperor penguins and elephant seals, blood oxygen (O₂) transport and depletion in these species were addressed with a three tiered approach. First, the transport of O₂ was examined by assessing heart rate (the principal determinant of blood O₂ depletion) during dives of emperor penguins. Secondly, O₂ transport was investigated at the biochemical level by characterizing the O₂-hemoglobin (Hb) dissociation curves for these species. Finally, the actual depletion of O₂ in the blood was documented by measuring blood O₂ partial pressure (Po₂) and temperature continuously during dives with a backpack recorder on translocated, juvenile elephant seals. Application of the O₂-Hb dissociation curve to Po₂ dive data also allowed for calculation of % Hb-saturation during dives. These studies revealed physiological responses and biochemical adaptations that contribute to the remarkable dive capacity of these species, including: 1) In contrast to any other diving bird, but similar to that of seals, emperor penguin heart rate while diving is significantly lower than resting rate, with values as low as 6 beats per minute in longer dives. This suggests parsimonious O₂ utilization and allows extended dive time. 2) The hemoglobin of the emperor penguin has a significantly higher affinity for O₂ as compared to other birds. It is in the range of seals and other marine mammals, allowing for more complete utilization of the respiratory O₂ store and increased blood O₂ content when Po₂ is low. 3) The elephant seal possesses exceptional tolerance to low Po₂ in the blood, with arterial Po₂ of 12 -23 mmHg and venous Po₂ of 2-10 mmHg at the end of routine dives. These Po₂ values correspond to hemoglobin saturations as low as 1-26% and O₂ contents of 0.3 (venous) and 2.7 ml O₂ dl⁻¹ blood (arterial). Temperature data collected during elephant seal studies revealed that core body temperature is preserved during diving, inconsistent with previous assertions of hypometabolism and a cold induced Q₁₀ effect during diving. Such results support the hypothesis that these species routinely "push the envelope" of the usual physiological limits of homeotherms to achieve such extraordinary dives Doctoral or Postdoctoral Thesis Elephant Seal Elephant Seals Emperor penguins University of California: eScholarship |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
UCSD Dissertations Academic Marine biology. (Discipline) |
spellingShingle |
UCSD Dissertations Academic Marine biology. (Discipline) Meir, Jessica Ulrika Blood oxygen transport and depletion : the key of consummate divers |
topic_facet |
UCSD Dissertations Academic Marine biology. (Discipline) |
description |
To investigate the physiological enigma of the impressive dives of emperor penguins and elephant seals, blood oxygen (O₂) transport and depletion in these species were addressed with a three tiered approach. First, the transport of O₂ was examined by assessing heart rate (the principal determinant of blood O₂ depletion) during dives of emperor penguins. Secondly, O₂ transport was investigated at the biochemical level by characterizing the O₂-hemoglobin (Hb) dissociation curves for these species. Finally, the actual depletion of O₂ in the blood was documented by measuring blood O₂ partial pressure (Po₂) and temperature continuously during dives with a backpack recorder on translocated, juvenile elephant seals. Application of the O₂-Hb dissociation curve to Po₂ dive data also allowed for calculation of % Hb-saturation during dives. These studies revealed physiological responses and biochemical adaptations that contribute to the remarkable dive capacity of these species, including: 1) In contrast to any other diving bird, but similar to that of seals, emperor penguin heart rate while diving is significantly lower than resting rate, with values as low as 6 beats per minute in longer dives. This suggests parsimonious O₂ utilization and allows extended dive time. 2) The hemoglobin of the emperor penguin has a significantly higher affinity for O₂ as compared to other birds. It is in the range of seals and other marine mammals, allowing for more complete utilization of the respiratory O₂ store and increased blood O₂ content when Po₂ is low. 3) The elephant seal possesses exceptional tolerance to low Po₂ in the blood, with arterial Po₂ of 12 -23 mmHg and venous Po₂ of 2-10 mmHg at the end of routine dives. These Po₂ values correspond to hemoglobin saturations as low as 1-26% and O₂ contents of 0.3 (venous) and 2.7 ml O₂ dl⁻¹ blood (arterial). Temperature data collected during elephant seal studies revealed that core body temperature is preserved during diving, inconsistent with previous assertions of hypometabolism and a cold induced Q₁₀ effect during diving. Such results support the hypothesis that these species routinely "push the envelope" of the usual physiological limits of homeotherms to achieve such extraordinary dives |
format |
Doctoral or Postdoctoral Thesis |
author |
Meir, Jessica Ulrika |
author_facet |
Meir, Jessica Ulrika |
author_sort |
Meir, Jessica Ulrika |
title |
Blood oxygen transport and depletion : the key of consummate divers |
title_short |
Blood oxygen transport and depletion : the key of consummate divers |
title_full |
Blood oxygen transport and depletion : the key of consummate divers |
title_fullStr |
Blood oxygen transport and depletion : the key of consummate divers |
title_full_unstemmed |
Blood oxygen transport and depletion : the key of consummate divers |
title_sort |
blood oxygen transport and depletion : the key of consummate divers |
publisher |
eScholarship, University of California |
publishDate |
2009 |
url |
http://www.escholarship.org/uc/item/7pk7c8sq http://n2t.net/ark:/20775/bb65541938 |
op_coverage |
1 PDF (xix, 106 p.) |
genre |
Elephant Seal Elephant Seals Emperor penguins |
genre_facet |
Elephant Seal Elephant Seals Emperor penguins |
op_source |
Meir, Jessica Ulrika. (2009). Blood oxygen transport and depletion : the key of consummate divers. UC San Diego: Retrieved from: http://www.escholarship.org/uc/item/7pk7c8sq |
op_relation |
http://www.escholarship.org/uc/item/7pk7c8sq qt7pk7c8sq http://n2t.net/ark:/20775/bb65541938 |
op_rights |
public |
_version_ |
1766401182307188736 |