Giraffe
The giraffe is quite amazing. What kind of extra-strength apparatus does it take to pump blood up a 10-feet neck to the brain, then manage its flow below the heart, six feet to the hooves?
When a giraffe bends way down for a drink, why doesn't it faint from blood rushing to the brain? Why doesn't it stagger dizzily from a lack of blood to the brain when it stands back up?
A giraffe's super muscular heart is two feet long and weighs about 25 pounds. It pumps 16 gallons a minute. A remarkable network of veins and one-way valves prevent back-flow, keeping blood from rushing to the head. Blood vessels in the head are more elastic and may reserve some blood, which keeps the animal from fainting as it stands. Smaller red blood cells and capillaries all help make oxygen absorption quicker.
Giraffe
The giraffe is quite amazing. What kind of extra-strength apparatus does it take to pump blood up a 10-feet neck to the brain, then manage its flow below the heart, six feet to the hooves?
When a giraffe bends way down for a drink, why doesn't it faint from blood rushing to the brain? Why doesn't it stagger dizzily from a lack of blood to the brain when it stands back up?
A giraffe's super muscular heart is two feet long and weighs about 25 pounds. It pumps 16 gallons a minute. A remarkable network of veins and one-way valves prevent back-flow, keeping blood from rushing to the head. Blood vessels in the head are more elastic and may reserve some blood, which keeps the animal from fainting as it stands. Smaller red blood cells and capillaries all help make oxygen absorption quicker.