The part where the spinal cord transforms into the brain is called the brain stem. In other words, all of your nerves in the body connects with the rest of the brain through the brain stem. All your vital functions like breathing, blood pressure regulation, heart rate, and digestion are controlled and processed in here autonomously without any active thoughts. The brain stem is made up three primary parts.
- Medulla oblongata - This is the part that controls the vital functions mentioned above.
- Pons - This processes all motor control functions including chewing and facial expressions.
- Midbrain - The topmost part of the stem that controls eye movements, hearing, and facial muscle movements.
- Diencephalon - It contains the hypothalamus, which regulates your body temperature, sleep cycles, hunger, and other hormonal activities, and thalamus, which controls your alertness, sleep, motor coordination, and emotions as part of the limbic system.