The best description about the brain stem is: it is the most important organ of our body's survival. It connects the brain and the spinal cord, controls the vital organs like the lungs and heart and it also coordinates the many essential body reflexes.
Food contains nutrients;however some foods is a better/richer sorce than others.
Segmented digestive system, appendages are animal characteristics.
Animals are a major group of organisms, classified as the kingdom Animalia or metozoa. Animals have several characteristics that set them apart from other living things. They are all eukaryotic and usually multicellular, which separates them from bacteria and most protists. Different animals differ in their own characteristics such as appendages, segmentation among other animal characteristics.