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.
Normal person
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.
Malnourished person
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 and
conspiracy 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.