linguistic:paraphrasing, structural:scholar_edition
Pulmonary

The major determinant of vascular resistance is small arteriolar (known as resistance arterioles) tone. These vessels are from 450 μm down to 100 μm in diameter (as a comparison, the diameter of a capillary is about 5 to 10 μm). Another determinant of vascular resistance is the pre-capillary arterioles. These arterioles are less than 100 μm in diameter. They are sometimes known as autoregulatory vessels since they can dynamically change in diameter to increase or reduce blood flow.