Three-hump camel

Nervous regulation of vessels perfect, but not the only one. There autoregulation and humoral regulation. The word "humoral" comes from the Latin humor - liquid. Of the heads of neurotransmitters known that humoral regulation actually exist, but the experience levy on two hearts says nothing about the vessels; try to understand that it is, this regulation does to the arteries. How does it compare with the nervous regulation, friends whether they are or have reason to start a new debate about who will bend. You can study the question on the familiar model: reflex with hearts on vessels.
How to separate nervous component reaction from humoral? This has to invite two Guinea: the donor and recipient. Using the pump constant flow we will perfusionist some vascular area donor blood, the donor and the same area of the recipient is also a blood donor. If a blood donor appears humoral regulators, their action in its pure form, without the emotional component, will appear on the recipient. Let's start with the hypogastric artery supplying the organs of the pelvis. If you apply irritation heart receptors weak solutions of nicotine (1:1000 and weaker), blood pressure and resistance pelvic vessels the blood flow is changed only from the donor, i.e. the answer pure reflex. If you increase the concentration of the stimulus to 1:100, the donor vessels meet immediate expansion and blood pressure falls from the donor, and after 50 seconds returns to the original level. Similar changes occur from the donor pool and hypogastric artery. But the recipient responds only a minute later after irritation; pelvic vessels widen, as the donor. I must say that it is, first, "humoral" extension, and secondly, that it is both experimental much longer and times and a half to two stronger than a reflex.
Similar things can be seen in the other vascular areas. Probably the most interesting here is that efferent impulses, addressed to the vessels may in some basins cause vasoconstriction, i.e. to influence their muscles "how to", and it may also act in the opposite way, but only if a strong irritation of receptors of the heart. This is typical of the blood vessels of the kidney and spleen. Another thing the intestine: everything remains normal. As for the skeletal muscles, humoral component of vascular reactions in the thigh muscle expressed brightly, and he is opposite reactions in blood pressure donor, reflex reactions.
As we can see, the power of humoral responses to the irritation of the receptors of the heart is very great, and the answers may not coincide with how to respond vasomotor afferente. This difference is determined, apparently features vascular region and the force acting on receptors in the heart, as well as the overall situation accordingly redistribution of blood.