Lunch break

Your body is not so important as you have your lunch. This does not mean that it is possible for life to eat candy, patience homeostatic mechanisms is not unlimited, but it's impossible to establish once and for all permanent ration how many grams of protein, fat and carbohydrates, too melancholy will take. Fortunately, nature vigilantly protect your homeostasis, and just as in the pulmonary alveoli the composition of the air is already stable and digestive apparatus (mainly small intestine) results in the order of their content. Of course, with the participation of vessels. It's amazing, but judge for yourself.
To digest a good dinner, we need not only the enzymes, but also a lot of liquid, which can only be obtained from blood, no other resources. The blood plasma, being filtrated through the capillaries of digestive glands, gets into the intestinal lumen blindly, but in accordance with your menu. Shortage of certain substances is compensated by the body in the bowel formed the chyme, similar to the composition of the standard diet, which has neither the desire nor the ability to observe. Thus, both the inputs in the body - in the lungs and digestive tract - one gets close, preliminary homeostasis. In the venous blood of the intestine absorbed therefore quite stable on the composition of the liquid, and it allows to avoid reflex disturbance regulation of circulation - chemo-receptor super-strong impacts. At the same time in the intestine are filtered and some waste is present in the blood, and the liquid is drawn from the blood, comes back to her.
So, between the intestine and blood is a constant and very intensive exchange of liquid; to make up the insufficient amount of liquid, the easiest way to get drunk. Blood loss is always accompanied by a thirst - remember wounded terkina. Drink, similar to blood plasma, more effective, than infusion into a vein, because the intestine in such conditions suck the liquid is not worse than the Sands of the Sahara.
As vessels react to blood loss, the reader may think himself - lowering blood pressure leads to vasoconstriction and increased cardiac work.
However, we have distract you from lunch. All the blood, flowing from the digestive system (except the rectum), flows are not in a common header, not in the Vena cava, and into the portal vein of the liver. This body is large and complex. Saturated your lunch blood takes place in the liver diverse biochemical process, and then mixed with venous blood to the liver, shall enter into the inferior Vena cava in the right atrium, where it is mixed with incoming top of Vena cava fats, then in the right ventricle and finally in the small circle, there is added deposited ingredients, and here it is again ready to serve you with full force.
Abdomen organs have in their vessels lot of blood. This is sort of the reserve where the blood can be rapidly mobilized. With hard work the muscles require huge flow: sometimes in the seventy and even a hundred times more, than alone. Note that the muscles mass - half of your weight. While running, when the General blood flow in a good athlete reaches 35 l per minute, the muscles receive about 80 % of this blood. This is achieved not only enhanced the work of the heart, but the sharp restriction of blood flow into the abdominal cavity. And not only the blood flow and blood volume in the vessels of the intestine, stomach, spleen. Spleen - something like blood depots, stores stock of blood, and with an increased number of erythrocytes. At the critical moment it is compressed and throws its reserves in the pot. The contraction of the abdominal muscles, the increased movement of the diaphragm with hard work contribute to the mobilization of blood resources; non-working muscles, the skin can also time to have a closer circulation until the start of the overheating of the body. Abdominal organs more enduring hardship. In addition to the kidneys, which, in truth, not the abdominal organs, they are behind the abdominal cavity and beyond. Here the flow is highly regulated. Through the kidneys within a few minutes passes all the blood, here she is cleared of excess salts, nitrogen products, and from the filtered urine much of the water is reabsorbed and returns blood together with salts and other body needs substances.
As already mentioned, the device reabsorption allows to maintain high blood pressure. Without this mechanism, all the liquid part of blood within minutes gone from the body. If the ureters goose going, like all birds, sewer (where the reabsorption), output, bird continuously and greedily drinking. No matter what else there is no time. It is clear that the blood flow to the kidneys cannot be reduced. Indeed, even small disturbances of renal blood circulation extremely dangerous, as it can lead to severe hypertension, a different mechanism from the usual. Well at least that kidney large margin: remove a single kidney does not lead to serious consequences.
If you have managed to digest it all, you're finished here lunchtime.