The brain is the central part of the nervous system responsible for integrating most sensory information and coordinating body function, both consciously and unconsciously, and complex functions such as thinking and feeling. Major parts of the brain are the medulla oblongata, pons, cerebellum, midbrain, diencephalon (thalamus and hypothalumus), and cerebrum.
The medulla oblongata appears as a swelling at the upper end of the spinal cord. Besides being a conduit for fibers running between the spinal cord and higher regions of the brain, it contains control centers for involuntary functions such as blood pressure, breathing, swallowing, and vomiting.
Just above the medulla are the pons and cerebellum. The pons relays information between higher regions of the brain and the cerebellum, which processes sensory information and helps coordinate movement.
The next segment, the midbrain, is primarily responsible for eye movement.
Above the midbrain lies the diencephalon, which is composed of two major parts: the thalamus and hypothalamus. The thalamus processes and integrates all sensory information going to the higher regions of the brain, while the hypothalamus is critical for homeostasis, the maintenance of the body`s internal environment. It influences nervous control of all internal organs and also serves as the master regulator of endocrine function by its control over the pituitary gland (HP axis).
The highest region of the brain is the cerebrum, which includes both the cerebral cortex that is visible on the outside of the brain as well as other internal structures. The cerebrum is responsible for conscious sensation and voluntary movement, as well as advanced functions such as thinking, learning, and emotion.