![]() One kick from a giraffe's hind leg has been known to kill a lion. On the other hand, the slow-moving giraffe can gallop 35 miles an hour if needed, and its long front legs are surprisingly sturdy. ![]() Sleeping is usually done standing up because lying down means having to stand up again-an awkward, time-consuming process. This makes it easy for the giraffe to reach high into the trees for food.īeing tall has its challenges! To get blood up to their heads, giraffes have massive hearts that pump at 2 or 3 times the pressure of a healthy human. The joint that connects the top vertebra to the skull allows the giraffe to tilt its head upward until it is almost perpendicular to the ground. A giraffe has the same number of vertebrae (neck bones) as humans and other mammals do, but each is more than 10 inches long. A giraffe's necks account for more than half of its height. Males stand up to 18 feet tall and females up to 15 feet tall. The giraffe is the tallest land-based mammal in the world. Masai giraffes are the tallest of the giraffe subspecies. They have jagged markings that look like grape or maple leaves. Masai giraffes range in the savannahs across central and southern Kenya and throughout Tanzania. ![]() ![]() "Reticulated" refers to the net-shaped pattern of their skin, which camouflages them in dense, dry vegetation. Reticulated giraffes live in open woodlands and wooded grasslands in Somalia, northern Kenya and southern Ethiopia. The slightly quicker heart rate compared to other animals of their size combined with an altered heartbeat allows the heart slightly more time to fill with blood between heartbeats for overall greater efficiency.The Oregon Zoo is home to representatives of two subspecies, the reticulated giraffe and the Masai giraffe. In summary: the giraffe’s heart is not bigger compared to most mammals, but rather has a thicker muscle on the left ventricle of the heart that generates enough force to fight gravity. For comparison, this rate is almost the same as a human’s average heart rate (60-100 bpm) and much higher than an elephant’s (30 bpm). In addition, the average resting heart rate is slightly higher than expected for an animal of that size at 40-90 beats per minute. In order to allow for adequate blood flow, the giraffe’s heart actually has an altered electrical rhythm, which allows more time for the left ventricle to fill with blood between each heartbeat. Having a smaller chambered left ventricle does pose some additional challenges. Instead, it was found that the left ventricle of the heart has incredibly thick, well-muscled walls and small chamber radius giving each heartbeat enough power to push blood around the body. In order to generate this force, it was previously hypothesised that the giraffe had a much larger heart relative to its body size, but recent research has revealed that there is not enough room in the body cavity for a larger heart. In order to reach the brain, the heart has to pump blood not only against gravity but also against the hydrostatic pressure of the blood already in the long vertical artery, requiring a tremendous amount of force. The left ventricle of the heart, on the other hand, has to pump the blood around the rest of the body, including all the way up to the head. The right ventricle of the heart only has to pump blood a relatively short distance to the lungs. But how exactly is this achieved?Ī giraffe heart weighs on average 11 kilograms and (like in all mammals) is composed of have two halves, the right and the left, which are each responsible for moving blood around the body. This is due to the fact that the giraffe’s head is on average 2 metres above its heart and the heart has to combat the forces of gravity to ensure that the brain gets adequate blood flow and oxygen. It reaches pressures of up to 280/180 mm Hg, which is twice that found in humans (120/80 mmHg). The giraffe has one of the highest blood pressures of any mammal.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |