Final answer:
The brain stem, including the midbrain, pons, and medulla oblongata, connects the brain to the spinal cord and regulates vital functions such as breathing, heart rate, and blood pressure. It also ensures the crossing of neural pathways for motor control and sensory integration.
Step-by-step explanation:
The brain stem is a crucial part of the central nervous system, connecting the brain with the spinal cord. It is comprised of three main parts: the midbrain, the pons, and the medulla oblongata. These structures play pivotal roles in controlling various involuntary functions that support life, such as breathing, heart rate, and blood pressure. The ascending neural pathways within the brain stem are involved in crossing signals, enabling the left hemisphere of the cerebrum to control the right side of the body and vice versa. This is essential for the coordination of motor control signals from the brain to the body and incorporates sensory information integration.
The brain stem also has control centers that regulate the cardiovascular and respiratory systems, and are instrumental in maintaining alertness and arousal. Additionally, it is involved in numerous autonomic functions and plays a part in complex actions like swallowing, walking, and the integration of motor and sensory information.