What happens to giraffes blood pressure when their necks are that long?

Giraffes have a normal blood pressure of 300, which is three times that of the average person! The heart also weighs more than 11 kilograms.

Tall land animals also have special difficulties with blood pressure. The larger the animal, the higher the blood pressure demands, so it needs a particularly powerful blood pump – the heart – and strong blood vessels. The giraffe is the tallest animal on land, and it has to lie on its feet and press its head from a height of several meters to the surface of the water to drink water, which is unique in its ability to prevent cerebral hemorrhage.

To this day, people are still diligently studying the mechanism by which giraffes are not prone to stroke. Humans often die from ruptures in animals, especially cerebral hemorrhages. This is the terrible price that humans will pay for walking upright.

The giraffe is the largest animal on land, it has horns for both sexes and does not shed for life. I don't know who the tourists here are. Heart disease patients, as far as I know, giraffe is a born high blood pressure patient, it not only blood pressure is three times the same as normal people, even the heart weighs more than 11 kilograms, only in this way, in order to raise its blood to three meters high in the mind, please carefully observe the giraffe running action, it runs in the shape of a "pendulum", which is commonly known as the crutch of all of us, which looks awkward; But it's not slow at all.

The medical scientist John Warren specifically measured the blood pressure of wild giraffes, and the average blood pressure was 260,160 mm Hg and up to 300 mm Hg. If you look at the average blood pressure of 120-80 mm Hg, giraffes can be regarded as extremely serious "hypertensive patients". However, it is strange that the pressure of the giraffe from the heart to the blood of the brain is not so high, and as the blood rises, the blood pressure instead slowly decreases, eventually ending up almost equal to the human blood pressure.

Why?

After years of research, scientists have discovered that the secret lies in the fact that the blood vessels in the lower part of the giraffe's brain have a strange valve that regulates blood flow - a network. This network is made up of delicate blood vessels of arteries and veins intertwined. Interestingly, there is a very thin blood vessel at the entrance and exit of the network.

As a result, even when the giraffe jerks its head, there is no excess blood entering the brain: conversely, when the giraffe jerks its head, there is no drastic decrease in blood to the brain. In essence, excess blood is trapped in a freely scalable network in case it is urgently needed.

Why is it that a giraffe, if it wants to press blood into its brain, must have extremely high blood pressure below its heart, and that its blood vessels must rupture and cause exudative hemorrhage, but why is that?

It turned out that the giraffe was carrying a talisman - armor. It has been found that the "armor" with a hard outer skin is not only responsible for maintaining the balance between the inner and outer layers of blood vessels, removing vascular obstacles, and protecting the heart, but also a "guard" against foreign invasions. Therefore, scientists figuratively call it "an impenetrable leather pressure bottle".

Even the purple tongue was found to be covered in a hard skin, so it's easy to see why giraffes are able to chew on the black locust that other animals don't dare to eat!

Interesting question, it should be high, it has to pump that high blood from the heart to the brain, hehe.

1. Theoretically, in the physiological state of any animal, the blood pressure must first meet the blood supply to the brain. As the tallest animal on land, the distance between the head and the heart of the giraffe is in meters, and there is no way to supply blood to the head without high pressure, therefore, the giraffe is a typical "high blood pressure", with an arterial systolic blood pressure of about 300mmHg.

2. The height of adult giraffes is meters, and the position of the heart is meters away from the head, while the distance from the human heart to the head is not as good as the height meters, the greater the distance between the heart and the head, the higher the pressure required in order to meet the blood supply to the head. The arterial systolic blood pressure of the human body is about 120mmHg, which satisfies the blood perfusion of the brain, while the arterial systolic blood pressure of giraffes is about 300mmHg in order to meet the blood supply to the brain. Such a high blood pressure requires a giraffe to have a very strong heart, which is 60 centimeters long and weighs 11 kilograms, which is about 30 times the size of a human heart.

In order to maintain blood pressure, not only such a huge heart is needed, but also a fast heart rate is needed to maintain blood pressure, and the heart rate of a giraffe is 150 beats per minute.

3. There are 7 valves in the jugular vein of the giraffe, and these 7 valves (venous valves) control the jugular venous flow of the giraffe through receptors. When the giraffe lowers its head, the valve of the jugular vein closes to prevent blood flow from the inferior vena cava from backing up into the jugular vein, allowing all blood to flow back to the heart. The closure of the venous valve will inevitably increase the pressure in the vena jugular veins because blood from the veins in the brain cannot flow back to the heart.

It is believed that giraffes must also have brain congestion when they bow their heads to drink water, and may have the same feeling as when humans do handstands, but because of the valve of the jugular vein, the giraffe's cerebral blood vessels can be prevented from being crushed.

Because the neck of the long-necked cave deer is so long, its heart is nearly 2 to 3 meters away from the brain, in order to be able to pump blood to the head more than 2 meters high, the giraffe's heart function is very strong, and it has to use high-pressure methods to deliver blood and liquid to the brain. If a giraffe's blood pressure belt is too low, it will have a lack of oxygen to the brain.

The long necks of giraffes are obvious to all, and their necks belong to the only creature in the world with such a long neck, which is their representative feature. For the long neck of giraffes, according to Darwin's theory of natural selection, it is because in the past, they were all survival of the fittest, the weak and the strong, and the natural environment changes quickly, if the neck is short, they cannot eat the leaves in high places, so in order to eat more food, their necks are longer and longer, and the short-necked ones are eliminated in the natural environment, and finally become giraffes that are only convenient to bend, and they choose to evolve in order to avoid more fierce competition. In addition, it has now been discovered that giraffes do not all like to eat tall leaves, so the term natural selection is still controversial.

Giraffes have long necks because of love, because they want to capture the heart of female giraffes, so male giraffes undergo physical changes, they continue to evolve, grow long necks to meet their beloved deer, male giraffes prefer to attack each other through their necks and heads, so if the neck has an advantage, it is easier to win. They can also fight other competitors to get a female giraffe option. So it's gender selection.

But only in males, female giraffes do not have an attack and should not have a long neck. So gender selection is currently just a claim that can be easily disproved.

In addition to this, there is also a saying for thermoregulation, which means increasing the surface area of the body to dissipate heat, because there are sweat glands on the neck that facilitate perspiration and create shadow areas. Another idea is that because they need to drink water, because giraffes have long legs, they can't escape from their predators faster when they drink water, so in order to survive better and avoid the consequences of long legs, they have evolved to stand up and drink water with long necks, so they don't have to bend down when drinking water.

There are many theories about the giraffe's long neck, natural selection as well as gender selection, including body heat dissipation and easy to drink water to escape, but after all, there is still no definite secret, and I hope to witness a conclusion in the future.

It is due to the fact that giraffes have mutated genetically in the process of evolution, and have a gene that makes their necks grow, so that they can survive more easily and eat the leaves of the trees in high places.

The reason why the neck of the deer is very long is because the deer needs to rely on its neck to get what it needs, of course, most of the cases are caused by natural factors.

Giraffes have evolved like this because they have to survive in nature and to survive on their own.