Final answer:
The cerebellum is not a part of the brainstem. The brainstem consists of the midbrain, pons, and medulla oblongata, and is involved in central nervous system functions, while the cerebellum handles balance and motor control.
Step-by-step explanation:
The brainstem consists of three components: the midbrain, the pons, and the medulla oblongata. The cerebellum, while it is located near the brainstem and is connected to it, is not considered a part of the brainstem itself.
The brainstem is a critical structure which connects the rest of the brain with the spinal cord. It is involved in important functions such as breathing, blood pressure regulation, and coordination of motor signals. The midbrain is responsible for processing visual and auditory information. The pons acts as a bridge between various parts of the brain, including the cerebellum, and assists with respiratory function. The medulla oblongata controls autonomic functions like heart rate and digestion.
The cerebellum, though it sits at the back of the brainstem, serves different functions, including balance, coordination, and fine motor control. Thus, it is not amongst the core parts of the brainstem.