This makes their blood pressure double the amount of most mammals! In the upper portion of their necks there is a complex pressure regulatation system that maintains blood flow when the giraffe bends down to drink.In their brain there are elastic blood vessels that connect to one way valves in the neck to prevent the head from swellin when they bend over.his makes their blood pressure double the amount of most mammals! In the upper portion of their necks there is a complex pressure regulatation system that maintains blood flow when the giraffe bends down to drink.
A plant hormone that promotes root formation and bud growth.An auxin is a growth regulating substance that can be found in the meristems of plants. The concentration of auxin has the deciding effect on how much (and where) growth occurs in a plant.
Light is so important for plant growth that they actually bend over backwards to get their share! Think about it this way. The plant cells that are on the shady side of the plant actually grow longer than the cells on the sunny side. These longer cells grow this way because of a chemical in them called an auxin. An auxin, is a plant growth hormone that helps regulate shoot growth. Under normal light conditions auxins are spread out in the plant. But when sunlight varies, auxin is broken down on the sunnier side of the stem. The higher concentration of auxin on the shady side causes the plant cells on that side to grow more so it bends toward the light. Because light is the energy source for plant growth, plants have evolved highly sensitive mechanisms for perceiving light.