Insertion of a narrow flexible tube, or catheter, through a blood vessel into the heart to withdraw blood samples, measure pressures, and inject contrast medium for imaging purposes is (2 words)

Insertion of a narrow flexible tube, or catheter, through a blood vessel into the heart to withdraw blood samples, measure pressures, and inject contrast medium for imaging purposes is called Cardiac catheterization. Cardiac catheterization is a procedure to examine how well the heart is working. A thin, hollow tube called a catheter is inserted into a large blood vessel that leads to the heart. It is normally performed if one has a disease of the heart muscles, valves, or coronary arteries. During this procedure, the pressure and blood flow in the heart can be measure and therefore a problem or a disease can be diagnosed; or the efficiency at which the heart is working.

By water evaporation from the leaves is created a negative pressure at the top of the tree that promotes the ascension  of the water through channels that are called xylem. there are also two molecule forces that are involved: the intra-water molecules cohesion (water molecules stick to each other) and the adhesion when the water molecules stick to the channels they are running in. this is what enables water to go from the roots to the top of a tall tree.