AKC Seminar: Giraffe physiology: How the cardiovascular system of Earth's tallest animal is adapted to gravity

with Professor Tobias Wang, Department of Bioscience, Aarhus University

Research Profile

Tobias Wang (PhD) studies a wide range of different animals to understand how their metabolism, digestion and cardiorespiratory physiology is adapted to various environments and behaviors. He was one of the driving forces for the Danish Cardiovascular Giraffe Research Programme, an interdisciplinary group of physiologists with the common goal of understanding the physiological adaptations to the high blood pressures of giraffes. Tobias Wang is head of the section of zoophysiology and chair of the comparative commission in the International Union of Physiological Sciences.

Abstract

With a height of more than 5 meters, giraffes are the tallest animals living on Earth and their bodily functions experience considerable gravitational stress. To perfuse the brain, the heart generates a high blood pressure, but contrary to common wisdom, we have shown that relative mass of the heart resemble other mammals (0.6% of body mass) and that the high pressures are generated by a thicker ventricular wall and a smaller ventricular lumen. We have identified sphincters, presumably with sympathetic innervation, in the major conducting arteries of the legs that may contribute to the protection against oedemas when the giraffes are standing quietly even though capillary pressures probably exceeds 400 mmHg. There are many unresolved questions on the mechanisms that protect the cerebral vasculature when the giraffes lower their head to drink. We believe that the intracranial vessels are protected by a rise in pressure of the cerebral spinal (such that the transmural pressure of the cerebral vessel does not change much), and there seems to be an effective barostic regulation and a pooling of blood in neck when the head is lowered. I will review our studies over the past 15 years and provide a perspective on the frustratingly difficult problems that remain to be solved.

Literature

How does the giraffe regulate brain blood pressure when lowering its head?

How does the giraffe maintain high enough blood pressure to secure brain perfusion?

Time

13 December 2019

14:00-15:00: Seminar and discussion
15:00-16:00: Post seminar servings and socializing

Venue

Auditorium 1, Universitetsparken 13, 2100 Copenhagen Ø

Registration

Participation is free, but please register here.

For PhD students

PhD students participating in August Krogh seminars receive 0,2 ECTS per seminar

Contact

Jens Frey Halling, jefh@nexs.ku.dk

Jonas Møller Kristensen, jmkristensen@nexs.ku.dk 

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