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.
Auxin also elongates root cells down into the ground, while at the same time elongating cells in the stem upward. This phenomenon, called gravitropism helps the plant develop a strong underground support system and get nutrients from the ground, and it also helps it grow tall towards the sunlight.ust like your body, plants have a variety of hormones, and auxins are a specific group of hormones that make plant cells grow. Auxins are not only critical to plant growth, but they were also the first class of plant hormones to be discovered.