Capillary glucose (such as in blood glucose monitoring), hemoglobin, pH and lactate Capillary blood sampling is generally performed by creating a small cut using a blood lancet, followed by sampling by capillary action on the cut with a test strip or small pipe. Contrary to a popular misconception, William Harvey did not explicitly predict the existence of capillaries, but he clearly saw the need for some sort of connection between the arterial and venous systems. He wrote, "…the blood doth enter into every member through the arteries, and does return by the veins, and that the veins are the vessels and
Helicine arteries of penis in increased levels of cyclic guanosine monophosphate (cGMP). cGMP in turn triggers relaxation of the smooth muscle and results in dilation of blood vessels. This signal is terminated when cGMP is broken down by the enzyme cGMP specific phosphodiesterase type 5 (PDE5), the enzyme that is targeted by sildenafil and other drugs that treat erectile dysfunction. By preventing PDE5 from breaking down cGMP, the effects of NO are amplified and vasodilation occurs, thus resulting in increased penile erection. Helicine arteries of penis The helicine arteries of penis are arteries in the penis. They are found in the corpora cavernosa penis.