vessels of the human circulatory system in formaldehyde solution closeup.

blood vessels artery aorta arteria arteries vein circulation circulatory system supply tubular formations tube arterioles arteriola venulum abdominal pulmonary venous organ human anatomy science isolated people body capillaries capillary heart organic glass jar closeup formalin formaldehyde solution biology research medicine medical red cloning cut out healthcare health life natural structure texture