Book contents
- Frontmatter
- Contents
- Editor, Associate Editors, Artistic Consultant, and Contributors
- Preface
- PART I CONTEXT
- 1 The Endothelium in History
- 2 Introductory Essay: Evolution, Comparative Biology, and Development
- 3 Evolution of Cardiovascular Systems and Their Endothelial Linings
- 4 The Evolution and Comparative Biology of Vascular Development and the Endothelium
- 5 Fish Endothelium
- 6 Hagfish: A Model for Early Endothelium
- 7 The Unusual Cardiovascular System of the Hemoglobinless Antarctic Icefish
- 8 The Fish Endocardium: A Review on the Teleost Heart
- 9 Skin Breathing in Amphibians
- 10 Avian Endothelium
- 11 Spontaneous Cardiovascular and Endothelial Disorders in Dogs and Cats
- 12 Giraffe Cardiovascular Adaptations to Gravity
- 13 Energy Turnover and Oxygen Transport in the Smallest Mammal: The Etruscan Shrew
- 14 Molecular Phylogeny
- 15 Darwinian Medicine: What Evolutionary Medicine Offers to Endothelium Researchers
- 16 The Ancestral Biomedical Environment
- 17 Putting Up Resistance: Maternal–Fetal Conflict over the Control of Uteroplacental Blood Flow
- 18 Xenopus as a Model to Study Endothelial Development and Modulation
- 19 Vascular Development in Zebrafish
- 20 Endothelial Cell Differentiation and Vascular Development in Mammals
- 21 Fate Mapping
- 22 Pancreas and Liver: Mutual Signaling during Vascularized Tissue Formation
- 23 Pulmonary Vascular Development
- 24 Shall I Compare the Endothelium to a Summer's Day: The Role of Metaphor in Communicating Science
- 25 The Membrane Metaphor: Urban Design and the Endothelium
- 26 Computer Metaphors for the Endothelium
- PART II ENDOTHELIAL CELL AS INPUT-OUTPUT DEVICE
- PART III VASCULAR BED/ORGAN STRUCTURE AND FUNCTION IN HEALTH AND DISEASE
- PART IV DIAGNOSIS AND TREATMENT
- PART V CHALLENGES AND OPPORTUNITIES
- Index
- Plate section
12 - Giraffe Cardiovascular Adaptations to Gravity
from PART I - CONTEXT
Published online by Cambridge University Press: 04 May 2010
- Frontmatter
- Contents
- Editor, Associate Editors, Artistic Consultant, and Contributors
- Preface
- PART I CONTEXT
- 1 The Endothelium in History
- 2 Introductory Essay: Evolution, Comparative Biology, and Development
- 3 Evolution of Cardiovascular Systems and Their Endothelial Linings
- 4 The Evolution and Comparative Biology of Vascular Development and the Endothelium
- 5 Fish Endothelium
- 6 Hagfish: A Model for Early Endothelium
- 7 The Unusual Cardiovascular System of the Hemoglobinless Antarctic Icefish
- 8 The Fish Endocardium: A Review on the Teleost Heart
- 9 Skin Breathing in Amphibians
- 10 Avian Endothelium
- 11 Spontaneous Cardiovascular and Endothelial Disorders in Dogs and Cats
- 12 Giraffe Cardiovascular Adaptations to Gravity
- 13 Energy Turnover and Oxygen Transport in the Smallest Mammal: The Etruscan Shrew
- 14 Molecular Phylogeny
- 15 Darwinian Medicine: What Evolutionary Medicine Offers to Endothelium Researchers
- 16 The Ancestral Biomedical Environment
- 17 Putting Up Resistance: Maternal–Fetal Conflict over the Control of Uteroplacental Blood Flow
- 18 Xenopus as a Model to Study Endothelial Development and Modulation
- 19 Vascular Development in Zebrafish
- 20 Endothelial Cell Differentiation and Vascular Development in Mammals
- 21 Fate Mapping
- 22 Pancreas and Liver: Mutual Signaling during Vascularized Tissue Formation
- 23 Pulmonary Vascular Development
- 24 Shall I Compare the Endothelium to a Summer's Day: The Role of Metaphor in Communicating Science
- 25 The Membrane Metaphor: Urban Design and the Endothelium
- 26 Computer Metaphors for the Endothelium
- PART II ENDOTHELIAL CELL AS INPUT-OUTPUT DEVICE
- PART III VASCULAR BED/ORGAN STRUCTURE AND FUNCTION IN HEALTH AND DISEASE
- PART IV DIAGNOSIS AND TREATMENT
- PART V CHALLENGES AND OPPORTUNITIES
- Index
- Plate section
Summary
GRAVITY AND THE CARDIOVASCULAR SYSTEM
The physiological systems of animals have adapted to Earth's gravity over the past hundreds of millions of years. In general, gravitational adaptations of the cardiovascular system are more pronounced in terrestrial species with greater height and thus greater gravity-dependent gradients of blood pressure from head to feet. For example, dinosaurs (1), tree-climbing snakes (2), giraffes (3), and other tall animals have evolved mechanisms to provide adequate blood flow and nutrition to their brains while restricting blood flow and tissue swelling in their legs. Terrestrial animals of short stature and marine animals probably require much less sophisticated cardiovascular adaptive mechanisms. At the other extreme, aquatic snakes have little ability to withstand gravity out of water and rapidly “faint” when placed head above tail (2). Moreover, when gravity is absent even over short periods of time, astronauts experience orthostatic intolerance upon readaptation to gravity (see Chapter 58). Because humans are relatively tall compared to other species of animals, they too have developed extensive and sophisticated regulatory mechanisms to maintain cerebral perfusion and prevent lower extremity edema while in an upright posture. In fact, most understanding of gravitational mechanisms to date relates to observations in humans. However, taller terrestrial animals, such as the giraffe, may allow better understanding of the physiological adaptations to gravity. For example, blood pressure in giraffes is high to pump blood to their brain, but high blood pressures in their feet would theoretically cause severe dependent edema.
Cardiovascular systems generate and regulate blood pressure to provide flow to tissues. This blood flow nourishes tissues by supplying oxygen (O2) and other nutrients, and by removing carbon dioxide (CO2) and other waste products.
- Type
- Chapter
- Information
- Endothelial Biomedicine , pp. 99 - 106Publisher: Cambridge University PressPrint publication year: 2007
- 3
- Cited by