Curiosity 3 of 10
3. The giraffe has the same seven vertebrae in its neck that you do
Despite its neck of nearly two meters, the giraffe has seven cervical vertebrae, the same number as a human being. The difference lies in size: each one can be longer than 25 centimeters.
Seven is the rule among mammals
Nearly all mammals have exactly seven vertebrae in the neck: the giraffe, the mouse, the whale, and you. The few known exceptions are sloths and manatees. What changes from one species to another is not the number, but the length and shape of each bone.
In the giraffe's case, each vertebra is almost the size of a 30-centimeter school ruler, and the joints between them are very flexible. This allows it to reach leaves high in the trees and also lower its head to the ground to drink water, spreading its front legs wide.
To carry blood to a head that sits so far above the heart, the giraffe needs blood pressure much higher than ours. It also has valves in the veins of its neck, which help control the blood flow when it suddenly lowers or raises its head.
The giraffe is the tallest land animal in the world: an adult male can exceed 5 meters. The heart alone, which has to overcome all that height, weighs about 11 kilograms and has walls much thicker than ours.
Did you know? The giraffe's tongue is dark, between purple and blue, and can measure about 45 centimeters. It uses the tongue to pull leaves that are between the thorns of acacia trees.
