Only the first and the second pair emerge from the cerebrum the remaining ten pairs emerge from the brainstem. In humans, there are traditionally twelve pairs of cranial nerves. Human Brain with Cranial Nerves: Cranial nerves are nerves that emerge directly from the brain, in contrast to spinal nerves, which emerge from segments of the spinal cord. The brainstem also has integrative functions, including cardiovascular system control, respiratory control, pain sensitivity control, alertness, awareness, and consciousness. Other areas of the cerebrum enable speech, judgment. In addition, upper motor neurons originate in the brain stem’s vestibular, red, tectal, and reticular nuclei, which also descend and synapse in the spinal cord. The largest part of the brain, the cerebrum initiates and coordinates movement and regulates temperature. The facial sensations have similar pathways and also travel in the spinothalamic tract and the medial lemniscus.ĭescending tracts are upper motor neurons destined to synapse on lower motor neurons in the ventral horn and intermediate horn of the spinal cord. Outside the meninges, the brainstem is shielded by the lower part of the skull. Brain stem: The brainstem is located at the juncture of the cerebrum and the spinal column. The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. It is protected by the meninges, which are composed of three layers of sheet-like connective tissue that envelop the brain and spinal cord. Make sure you know the information which you were given. The ascending pathways from the body to the brain are the sensory pathways, including the spinothalamic tract for pain and temperature sensation and the dorsal column, fasciculus gracilis, and cuneatus for touch, proprioception, and pressure sensation. The brainstem is a stem shaped structure, extending down from the posterior (back) part of the brain to the spinal cord. All information relayed from the body to the cerebrum and cerebellum and vice versa must traverse the brainstem. The brainstem has many basic functions, including regulation of heart rate, breathing, sleeping, and eating. It regulates the central nervous system (CNS) and is pivotal in maintaining consciousness and regulating the sleep cycle. The brain stem also plays an important role in the regulation of cardiac and respiratory function. This includes the corticospinal tract (motor), the posterior column-medial lemniscus pathway (fine touch, vibration sensation, and proprioception ) and the spinothalamic tract ( pain, temperature, itch, and crude touch). Though small, it is an extremely important part of the brain, as the nerve connections of the motor and sensory systems from the main part of the brain that communicate with the peripheral nervous system pass through the brainstem. The brainstem gives rise to cranial nerves 3 through 12 and provides the main motor and sensory innervation to the face and neck via the cranial nerves.

In vertebrate anatomy, the brainstem is the most inferior portion of the brain, adjoining and structurally continuous with the brain and spinal cord.

Different parts of brain stem function