Comparison of Brain Structure in Mammals, Amphibians, and Birds

The brain is a complex structure in all living species, even though they differ greatly in mammals, amphibians, and birds. It is the most important part of the body, because it maintains homeostasis and assists in every function. The brain structures of the three vertebrates, mammals, amphibians, and birds, have similar features and functions. There is still a great difference in the size, and importance of these structures in the brain. For instance, the bird brain is small in size, yet still very complex. The size and complexity of the cerebrum and cerebellum is the most notable difference in these vertebrates.

There are many similarities in the brain structure of the mammal, bird and amphibian. They have the several parts that are the same and perform the same function. For instance the medulla oblongata is the lowest portion of the brain (stem) and controls automatic functions. All three of these vertebrates have two hemispheres and different lobes. Each vertebrate also has a spinal cord that descends from the brain that carries nerve impulses to and from the body along with blood vessels. All vertebrates have spinal and cranial nerves associated with the brain and spinal cord. Also many systems are needed to maintain and control features of the body. For example the endocrine, autonomic, and peripheral systems are needed for full normal function of the animal. The ability to process information is very important. This involves the brain stem, many motor nerve cells, basal ganglia, and other important features. Even with these similar features there is still a large variety, even within the same species.

The mammalian brain is the most complex and the largest out of all the vertebrates. It has special features and characteristics that the others do not. “The unimpressive appearance of the human brain gives few hints of its remarkable abilities. It is about two good fistfuls of quivering pinkish gray tissue, wrinkled like a walnut,...