Is it correct to say that veins carry blood with high concentrations of waste products and arteries carry blood with high concentrations of nutrients explain?

Answer 1

It is certainly correct to say that Arteries carry blood with high nutrient concentrations. The nutrients the cells require are things like Glucose (or other fuels but usually glucose). This means that blood going to the cells (arteries) will carry much glucose, which will be taken up by the cells at the capillary beds, and vessels traveling away from the cells (veins) will not carry much at all. There is one major eception to this however. The Hepatic Portal Vein is, as its name suggests, a vein between two organs. To be precise it goes from the Intestinal Tract to the LIver carrying all the nutrients the intestinea have absorbed. It is important to note that the "concentrations" of gasses are never used, not even in solution, instead we ude their Partiel Pressures. There is almost not oxygen dissolved in the blood as it is entirely non-polar and so cannot interact with the water molecules so its partial pressure within the Plasma is very low everywhere. However there is a large ammount of it present in the arterial blood bound to Heamaglobin within the Red Blood Cells. So depending on the definition of "high concentration" it could be accurate to say arteries carry blood with high concentrations of nutrients. A similar situation is true for the waste products in venous blood. Carbon Dioxide is the only waste product of respiration (exept water) and, as a gas, should really be meassured using partial pressure. There is some CO2 dissolved directly in the plasma and it reacts with the water to produce HCO3 (bicarbonate) ions and free H+ ions. So for this reason it is reasonable to state that venous blood contains high concentration (again depending on you definitions) of waste products. Or is it... In the Pulmonary Circulation is the opposite of the rest of the circulation. That is to say that the Pulmonary Artery, although it carries a reasonable high concentration of glucose, is has very little oxygen in it (including in the red blood cells). The Pulmonary Vein carries about the same concentration of glucose as most arteries and but it has a very high Oxygen content and as all the CO2 was released into the lungs it has a low CO2 content. In these terms arteries can be said to have low nutrient concentration and the veins can have a low waste concentration.