How is blood redirected to different tissue?
Answers:
There are lots of ways. The main ways are arteries, capillaries and veins.
Capillaries
The short answer is: Blood is redirected to different tissues via smooth-muscle sphincters that surround arterioles.
Here is the longer answer:
The arrangement of blood vessels, in terms of size (diameter) is as follows: arteries, such as the aorta, are the largest in in diameter; next, arteries branch into smaller vessels known as arterioles; arterioles then branch to smaller vessels called capillaries. Capillaries are where nutrient and gas exchange occur between the blood vessels and the tissues. Capillary beds are the "goal" for blood - the arteries and arterioles are simply tubes to help the blood get to the capillary beds as quickly and smoothly as possible.
Sometimes you need more blood in certain parts of your body. E.g., after you eat, more blood is redirected to the capillary beds in your gut. When you blush, more blood is redirected to the capillary beds in your cheeks. When you exercise on a hot day, more blood is redirected to your skin to shed excess heat.
The control mechanism for this redirecting of blood are small bands of smooth muscle that form a ring around the arterioles. Recall, arterioles are blood vessels that are found just before capillaries. These rings of smooth muscle form a "sphincter" around the arteriole. This smooth muscle sphincter is a structure that can control the diameter of the blood vessel, causing it to get larger (dilate) or smaller (constrict).
This sphincter of smooth muscle surrounds the arteriole, so that when the smooth muscle contracts, the sphincter tightens, making the diameter of the arteriole smaller, allowing less blood to pass through.
When the smooth muscle sphincter relaxes, the diameter of the arteriole gets larger, allowing more blood to pass through. That make sense? This mechanism is what controls the degree of blood flow through the body.
What tells the smooth muscle to tighten or relax? This is done by your nervous system: specifically the autonomic nervous system.this is the part of your nervous system that controls all the aspects of your body that go on without conscious control (e.g. heart rate, how fast you breathe, how large your pupil gets, etc.).
The body literally has thousands of these smooth muscle sphincters, redirecting blood flow as needed, all the time, day and night, to various tissues. It's quite an elaborate and intricate system when you think about it!
Hope that helps -
from the heart through the arteries then into small capiliaries. The veins carry the blood away from the tissues. The direction is controlled by small valves in the caplillaries that direct the flow accordingly.
there isn't a single drop of blood that hasn't been 'redirected' at least a couple of times in the human body.
i guess its directed 2 a particular place in the same way its directed & redirected 2 everywhere else.
The answers post by the user, for information only, UKQnA.com does not guarantee the right.