Your brain is located within the cranial cavity of the skull. Thin membrane layers called meninges surround it, and it is suspended in cerebrospinal fluid. The main divisions of your brain are the brainstem, cerebellum, diencephalon, and cerebrum.
The brainstem is a small part connecting the brain to the spinal cord (they are physically one entity). It is mainly responsible for many subconscious, vital functions of your body, such as breathing and controlling your heart rate. The brainstem is made up of the medulla oblongata, the bridge (pons), and the midbrain (mesencephalon). Behind the brainstem is the cerebellum, which is often referred to as the “Little Brain” because of its similar structure. It controls voluntary movement, muscle coordination, muscle memory, and much more.
The diencephalon controls your endocrine system and sleep-wake cycle and plays an essential role in maintaining the body’s homeostasis, just to mention a few. It consists of many structures, including the hypothalamus and thalamus. Finally, the largest part of your brain, the cerebrum, forms the cerebral cortex, which consists of two hemispheres of your brain responsible for thinking, memory processes, and the ability to speak. The surface of the hemispheres is increased by folds, allowing you to fit billions of neurons in your brain!
Figure 1: Anatomy of the Brain