Something which many may find interesting..
Have you ever noticed that in many of the commercials aimed at earning donations
to help people in developing countries
show kids with huge stomachs? When I was younger, I thought, why do they need help when their stomachs are so full? Well, here's the answer.
The big stomachs are a direct result of severe malnutrition
. Most if not all of us will never experience that kind of hunger. Blood
plasma contains a multitude of plasma proteins
. These proteins must be manufactured
in the body.
When blood runs through the arteries
, they eventually reach the capillaries
where the actual nutrient exchange occurs. This occurs by a mechanism that doesn't seem to make sense. At the beginning of the capillary bed, most of the plasma leaves the blood vessels into the tissue. This is due to the osmotic pressure
gradient. This oxygenated blood
is able to both supply oxygen and carry away carbon dioxide. Many hormones
and nutrients are also filtered into the tissues this way. At the end of the capillary bed, the blood in the veins
is very concentrated. This is because many of the larger plasma proteins are unable to pass through into the tissues and stay in the capillaries. This osmotic pressure, causes the plasma which has left the capillaries to go back into the veins. Not all of the plasma returns. Some of it goes into the lymphatic
system. The returned blood goes from the veins eventually go back to the heart
and the cycle starts again.
The cycle is the same for the most part. However, when you are in a state of starvation
, your diet would not contain adequate amounts of proteins. Hence, the large plasma proteins which would be present in the blood are not there. This lessens the osmotic pressure gradient that is responsible for the return of plasma back into the blood vessels. The lymphatic system is not able to handle this increase in fluid volume and so the tissues retain much of the plasma. This causes swelling
, and so an enlargement of tissues.
I hope this clears up any misconceptions
theories going around about world vision
and such. The people in those countries do really need help. Eventually the swelling of the tissues is offset by the lack of tissue to swell and eventually death