Giraffes appear to have a small but extremely powerful heart. This allows the blood to be pumped to the head through its long neck. Researchers of the University of Pretoria (South Africa) have discovered this.
The research was performed on giraffes that had been killed in Zimbabwe in 2006. The researchers discovered that the heart is relatively small but contains extraordinarily strong muscles that make the heart work much more powerfully than that of most other animals.
Before it was assumed that the giraffe heart was very large, but that assumption was based on just one observation in the fifties.
Besides the powerful heart there are also adjustments in the cardio-vascular system to deal with the high blood pressure. Blood vessels can be expanded or contracted when necessary causing the volume in the system to change.
The results of this research were published in the scientific journal Comparative Biochemistry and Physiology Part A.