Brain

The human brain, together with the spinal cord, is a vital part of the central nervous system. It is protected by the meninges and housed within the cranial cavity inside the skull. Acting as the command center of our body, the brain consists of distinct regions: the forebrain (or prosencephalon), midbrain (or mesencephalon), and hindbrain (or rhombencephalon).

The hindbrain consists of the cerebellum, medulla oblongata, and pons. The cerebellum, located in the posterior cranial fossa, is responsible for subconscious regulation of balance, motor coordination, and planning. The midbrain serves as a connection between the forebrain and the hindbrain. Together, the medulla, pons, and midbrain form the brainstem, found in the posterior cranial fossa just in front of the cerebellum. The brainstem acts as a pathway for various neuronal tracts that connect the spinal cord to the brain. Additionally, the brainstem contains control centers for regulating cardiovascular and respiratory rhythm. It also contains the reticular formation, which plays a crucial role in arousal, consciousness, and regulating the sleep-wake cycle. Moreover, the brainstem contains cranial nerve nuclei that give rise to pairs of cranial nerves that enable communication between the brain and various parts of the body.

Above the midbrain lies the forebrain, also referred to as the prosencephalon. It can be further divided into the diencephalon and telencephalon. The diencephalon, which originated earlier in evolutionary development, encompasses structures surrounding the third ventricle, such as the thalamus, hypothalamus, and subthalamus. On the other hand, the telencephalon represents the two cerebral hemispheres (known as the cerebrum) that cover the diencephalon. Each cerebral hemisphere comprises an overlying layer of gray matter called the cerebral cortex, which encloses the underlying subcortical white matter and various deeply situated gray matter nuclei, including the basal nuclei.