The liver has two blood vessels which supply it with blood: the hepatic artery supplies it with oxygen, and the hepatic portal vein brings blood from the digestive system
If you get a cut or a graze on your skin, phagocytes will collect at the site of the damage, to engulf and digest any microorganism that might possibly get in.
Due to the fact that the capillaries are so narrow, the oxyHb in the red blood cells is taken very close to the tissues which need oxygen. The oxygen, therefore, has only a short distance to diffuse.
As the cells in our bodies respire, they produce Carbon Dioxide
This Carbon Dioxide diffuses through the walls of the capillaries into the blood
Most of the Carbon Dioxide is carried by the bloodplasma in the form of hydrogencarbonate ions HCO³ˉ and a small amount is carried by the Hb in the red blood cells
Blood containing Carbon Dioxide is returned to the heart in the veins and then to the lungs in the pulmonary arteries
Carbon Dioxide diffuses out of the blood and is passed out of the body when we respire