How do giraffes breathe

With such a high neck, giraffes are exposed to practically all kinds of airborne elements, by this I mean especially dust particles in the air, direct sunlight. Due to the environment where the giraffe lives, such as the African savannah, where the incidence of the sun is tremendous and there is a lot of dust and sand both on the ground and in the air, the giraffe is adapted with two amazing physical characteristics to protect it from both inclemencies.

The first physical adaptation is its tongue, whose dark blue color allows it to eat from the tall bushes without suffering sunburn from long exposure, and the second adaptation is its nostrils. This might seem a bit repulsive to us humans, but this adaptation of both the nostrils and the tongue is a wonder of nature. The nervous system connects the organs of our body, forwards stimuli and commands from the brain to the organs.

So it makes sense to keep connections between the brain and the corresponding target organs as short as possible. Usually, it is like that. The larynx nerve is an exception. Actually, the distance from the brain to the larynx is not that great. However, the nerve coming from the brain does not pull directly to the larynx, but first further down, around the aortic arch above the heart and then back up towards the larynx. The laryngeal nerve makes this loop in all mammals, even those with an elongated neck.

In the giraffe, this leads to an extremely curious course of the nerve. Instead of the required length of maybe cm with a direct connection between the brain and larynx, the length of the nerve extends to several meters. How is this curious course of the larynx nerve to be explained?

In this case, an engineer would be in dire need of an explanation. An evolutionary biologist, on the other hand, can refer to the tribal history of vertebrates. Our fish-like relatives had no larynx and no throat. However, they already had the forerunners of the larynx nerves, which had a completely different task with them.

They conducted nerve impulses from the head to the neighboring gill apparatus and back. In their course, they also moved around blood vessels. Female giraffe necks, on average, are two feet shorter than male necks!

Darwin himself alludes to some of these as alternate possibilities. There is no fossil record showing a gradual increase in giraffe neck length. The blood pressure generated by the heart must be extremely high to pump blood to the head. But when the giraffe bends its head to the ground it encounters a potentially dangerous situation. It must lower its head between its front legs, putting a great strain on the blood vessels of the neck and head.

The blood pressure plus the weight of the blood in the neck could produce so much pressure in the head that the blood vessels would burst.

Mercifully, however, the giraffe is equipped with an adaptational package, including a coordinated system of blood pressure control. When the animal takes in a fresh breath, the oxygen-depleted previous breath cannot be totally expelled. For the giraffe this problem is compounded by the long trachea that will retain more dead air than man can inhale in one breath. The secret lies in an extremely tough skin and an inner fascia [fibrous connective tissue] that prevents blood pooling.

This skin combination has been studied extensively by NASA scientists in their development of gravity-suits for astronauts. The capillaries that reach the surface are extremely small, and the red blood cells are about one-third the size of their human counterparts, making capillary passage possible. It quickly becomes apparent that these unique facets of the giraffe are all interactive and interdependent with its long neck.

The smaller red blood cells allow for more surface area and a higher and faster absorption of oxygen into the blood. Giraffes breathe in oxygen and release carbon dioxide just like humans and other mammals do.

When a giraffe breathes oxygen into its body, the air travels down the trachea and into the lungs. The lungs fill up with oxygen, and the giraffe's circulatory system takes this much-needed gas to the rest of the giraffe's body. When a giraffe breathes out, carbon dioxide is released into the air, which the trees and plants need for photosynthesis. A giraffe's lungs are about eight times larger than a human's lungs because if they were not, a giraffe would breathe the same air over and over again.

Since the giraffe's trachea is so long and narrow, there is a big volume of dead air in the giraffe. However, the giraffe's breathing rate is about one-third slower than man's breathing rate to help with this dead air problem.