1.   If it happens too quickly, the gas forms bubbles in the blood that can block small arteries and cause the bends.

2.   These then enter small arteries and migrate on the endothelium to their predilection site in the cranial mesenteric artery and its main branches.

3.   And it was already known that nitric oxide can be produced in the walls lining small arteries and that this could have an effect on their diameter.

4.   Collateral circulation refers to small arteries that connect two larger coronary arteries or different parts of the same artery.

5.   If oxygen levels in the small arteries are high, Stamler said, the hemoglobin does not change shape.

6.   In the small arteries, the model says, the hemoglobin senses how much oxygen is present in nearby tissue.

7.   It travels to the small arteries, where it often drops two oxygens before making its way into a capillary.

8.   Nitroglycerine and other drugs dilate the remaining small arteries to increase blood supply.

9.   Smaller ones may move along until they reach a very small artery.

10.   When hemoglobin exits from the capillary, Stamler said, it makes a U-turn into one of the tiny veins that lie smack up against the small arteries.