Grandparents have always been important. Today, they're even more important. In busy, two-career and single-parent families, an involved grandparent goes a long way to filling a void for children. In extreme situations, the courts have found it's often a grandparent who can reach a troubled teen when no one else can.
Here's how to enlarge your veins and arteries for plasma donation: 1  Heat up your arm. When veins become overheated, they expand, and draw closer to the skin. 2  Hold off on drinking and smoking. Both smoking and drinking alcoholic beverages makes veins and arteries smaller and harder. 3  Hold off on the caffeine.
Veins have much thinner walls, because the blood they carry is under low pressure. VEINS have valves that aid the return of blood to the heart and prevent blood from going backwards. ARTERIES do not have valves, except for the semi-lunar valves of the pulmonary artery and the aorta. ARTERIES have relatively narrow lumens, VEINS have relatively wide lumens.