a) Venous hyperemia of the kidney cortex in the control group animals. H and E staining. 10Xoc.lens, 40Xobj.lens; b) The hyperemia zone of the kidney cortex blood vessel in animals after physical exertion and the lemongrass use. H and E staining. 10Xoc.lens, 40Xobj.lens; c) Moderate stagnation in the kidney cortex blood vessels in animals using the drone brood after physical exertion. H and E staining. 10Xoc.lens, 40Xobj.lens.