cross section of y-d junction in blood capillary

blood vein bloodstream artery red biology flowing anatomy inside science hemoglobin organic vessel wall capillary body cell cut three dimensional biological flow cardiovascular system layered vascular tissue close-up cross process medical condition magnification healthcare medicine tunica media intima externa plasma shape healthy structure circulatory scientific normal organ junction adventitia circulation slice capillaries layer veins arteries cells erythrocyte isolated close health microscopic rendering