Assuming this refers to blood vessels, the answer is the capillaries.
capillaries
water
The actual air exchange takes place in the alveoli of the lungs
herobrine's mansion, yeah motherfucks
It takes place between the alveoli and the blood capillaries
the oxygen you breath in is passing in different kinds of organs but the gas exchange is occurring in the alveoli.
Capillaries
Pure diffusion ... everything flows from high concentration toward low. No energy is expended in these exchanges.
Chemical reactions in the body take place in water.
Chemical reactions in the body take place in water.
The exchange of oxygen takes place in the alveoli. It is found in our lungs
water
Their are many nutrient in our body that we need. But we mostly need water.
Mainly in the small intestine, but nutrient absorption also occurs in the rumen and omasum.
no
vitamins
Vitamins
stomata