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These nerves are longer in the giraffe than in any other living animal the left nerve is over 6 ft. 7 in long. Each nerve cell in this path begins in the brainstem and passes down the neck along the vagus nerve , then branches off into the recurrent laryngeal nerve which passes back up the neck to the larynx. Thus, these nerve cells have a length of nearly 16 ft. in the largest giraffes. The structure of a giraffe's brain resembles that of domestic cattle. The shape of the skeleton gives the giraffe a small lung volume relative to its mass. Its long neck gives it a large amount of dead space , in spite of its narrow windpipe. These factors increase the resistance to airflow. Nevertheless, the animal can still supply enough oxygen to its tissues.
The circulatory system of the giraffe has several adaptations for its great height. Its heart, which can weigh more than 25 lb and measures about 2 ft long, must generate approximately double the blood pressure required for a human to maintain blood flow to the brain. As such, the wall of the heart can be as thick as 3.0 in.Giraffes have unusually high heart rates for their size, at 150 beats per minute. In the upper neck, a rete mirabile prevents excess blood flow to the brain when the giraffe lowers its head. The jugular veins also contain several (most commonly seven) valves to prevent blood flowing back into the head from the inferior vena cava inferior in and right atrium while the head is lowered. Conversely, the blood vessels in the lower legs are under great pressure (because of the weight of fluid pressing down on them). To solve this problem, the skin of the lower legs is thick and tight; preventing too much blood from pouring into them.
Giraffes have esophageal muscles that are unusually strong to allow regurgitation of food from the stomach up the neck and into the mouth for rumination . They have four chambered stomachs, as in all ruminants, and the first chamber has adapted to their specialized diet. The giraffe's intestines measure up to 260 ft in length and have a relatively small ratio of small to large intestine. The liver of the giraffe is small and compact. A gallbladder is generally present during fetal life, but it may disappear before birth.
As for the conservation status, the Giraffe species is a least concern but the West African and the Baringo Giraffe are endangered. in 1999 the population was 140'000, (of which 40% were in or around protected areas and private lands) and such numbers were thought capable of being maintained were they adequately protected. Current estimates have the population at less than 80'000 individuals across all (sub)species. This is a considerable drop in the last decade and shows that the plight of giraffe is in real danger. Efforts are underway to build up an accurate census of the entire population.
The circulatory system of the giraffe has several adaptations for its great height. Its heart, which can weigh more than 25 lb and measures about 2 ft long, must generate approximately double the blood pressure required for a human to maintain blood flow to the brain. As such, the wall of the heart can be as thick as 3.0 in.Giraffes have unusually high heart rates for their size, at 150 beats per minute. In the upper neck, a rete mirabile prevents excess blood flow to the brain when the giraffe lowers its head. The jugular veins also contain several (most commonly seven) valves to prevent blood flowing back into the head from the inferior vena cava inferior in and right atrium while the head is lowered. Conversely, the blood vessels in the lower legs are under great pressure (because of the weight of fluid pressing down on them). To solve this problem, the skin of the lower legs is thick and tight; preventing too much blood from pouring into them.
Giraffes have esophageal muscles that are unusually strong to allow regurgitation of food from the stomach up the neck and into the mouth for rumination . They have four chambered stomachs, as in all ruminants, and the first chamber has adapted to their specialized diet. The giraffe's intestines measure up to 260 ft in length and have a relatively small ratio of small to large intestine. The liver of the giraffe is small and compact. A gallbladder is generally present during fetal life, but it may disappear before birth.
As for the conservation status, the Giraffe species is a least concern but the West African and the Baringo Giraffe are endangered. in 1999 the population was 140'000, (of which 40% were in or around protected areas and private lands) and such numbers were thought capable of being maintained were they adequately protected. Current estimates have the population at less than 80'000 individuals across all (sub)species. This is a considerable drop in the last decade and shows that the plight of giraffe is in real danger. Efforts are underway to build up an accurate census of the entire population.