except for the pulmonary vein) Allows diffusion of gases and nutrients from blood into the body cells Wall Thick, muscular Thinner Very thin, one cell thick Lumen Small Large Very small ...
except for the pulmonary vein) Allows diffusion of gases and nutrients from blood into the body cells Wall Thick, muscular Thinner Very thin, one cell thick Lumen Small Large Very small ...
1 年
Green Matters on MSNWhy Are Veins More Blue on Some People Than Others? The Science Behind This PhenomenonExercise increases your blood pressure, which can expand the veins, and while lifting heavy weights, muscle contractions can ...
一些您可能无法访问的结果已被隐去。
显示无法访问的结果