other tissues showing a distinct , but less prominent , radioactivity were the endocardium of the heart atria , the walls of the great afferent and efferent vessels in the thoracic cavity , the choroid plexuses of the brain ventricles , the pia mater , brown fat , the muscularis layer of the stomach and the intestines , the lamina propria of the villi in the small intestine and the walls of a few small blood vessels in the kidney medulla .
C0021853
intestines
C0021852
small intestine