But what part of the brain controls balance? Picture your brain like a factory. There are countless little gears, conveyor belts, and workers milling about, each of them serving a unique purpose to keep you moving through the world. And while your balance system engages several parts of your brain, the main part of the brain that controls balance is the cerebellum.
The cerebellum controls a number of functions including movement, speech, balance, and posture. There are several other parts of the brain that also contribute to balance functions, including something known as the vestibular system.
Think of the vestibular system as a messenger service. Located in the inner ear, the vestibular system provides your brain with information on things like motion, the position of your head, and sudden movements. Overall, the vestibular system helps you maintain a sense of equilibrium, preventing falls and dizziness. The cerebrum front of brain comprises gray matter the cerebral cortex and white matter at its center.
The largest part of the brain, the cerebrum initiates and coordinates movement and regulates temperature. Other areas of the cerebrum enable speech, judgment, thinking and reasoning, problem-solving, emotions and learning.
Other functions relate to vision, hearing, touch and other senses. The cerebral cortex is divided into two halves, or hemispheres. It is covered with ridges gyri and folds sulci. The two halves join at a large, deep sulcus the interhemispheric fissure, AKA the medial longitudinal fissure that runs from the front of the head to the back. The right hemisphere controls the left side of the body, and the left half controls the right side of the body.
The two halves communicate with one another through a large, C-shaped structure of white matter and nerve pathways called the corpus callosum. The corpus callosum is in the center of the cerebrum. The brainstem middle of brain connects the cerebrum with the spinal cord. The brainstem includes the midbrain, the pons and the medulla. The spinal cord extends from the bottom of the medulla and through a large opening in the bottom of the skull. Supported by the vertebrae, the spinal cord carries messages to and from the brain and the rest of the body.
Like the cerebral cortex, it has two hemispheres. The outer portion contains neurons, and the inner area communicates with the cerebral cortex. Its function is to coordinate voluntary muscle movements and to maintain posture, balance and equilibrium. Three layers of protective covering called meninges surround the brain and the spinal cord. Each brain hemisphere parts of the cerebrum has four sections, called lobes: frontal, parietal, temporal and occipital.
Each lobe controls specific functions. The pituitary gland governs the function of other glands in the body, regulating the flow of hormones from the thyroid, adrenals, ovaries and testicles. It receives chemical signals from the hypothalamus through its stalk and blood supply.
The hypothalamus is located above the pituitary gland and sends it chemical messages that control its function. It regulates body temperature, synchronizes sleep patterns, controls hunger and thirst and also plays a role in some aspects of memory and emotion.
Small, almond-shaped structures, an amygdala is located under each half hemisphere of the brain. A curved seahorse-shaped organ on the underside of each temporal lobe, the hippocampus is part of a larger structure called the hippocampal formation. It supports memory, learning, navigation and perception of space.
The vestibular system uses two other organs, known as the otolith organs, to detect linear acceleration, gravitational forces, and tilting movements. There are two otolith organs in the vestibular labyrinth: the utricle and the saccule.
The utricle is specialized to detect movement in the horizontal plane, while the saccule detects movement in the vertical plane.
The process of sensation in the otolith organs bears some similarity to the process in the semicircular canals, but there are also some distinct differences. Like the semicircular canals, the otolith organs also contain a sensory organ where hair cells can be found; in this case, however, it is called the macula.
As in the semicircular canals, there is a gelatinous layer above the hair cells; in the otolith organs, however, there is another fibrous structure called the otolithic membrane above the gelatinous layer.
The otolithic membrane has small crystals of calcium carbonate called otoconia embedded within it. These crystals make the otolithic membrane heavier than the rest of the structure; when linear acceleration occurs, it causes the otolithic membrane to shift relative to the macula, which leads to the displacement of hair cells and thus the release of neurotransmitters from these cells.
The structure of the otolith organs makes them especially sensitive to movements like linear acceleration and head tilts. The vestibular system uses this information about movement obtained via the semicircular canals and otolith organs to maintain balance, stability, and posture; one way it does this is through its involvement in reflex actions.
For example, the vestibulo-ocular reflex VOR is a mechanism involving connections between the vestibular system and the muscles of the eyes that allows our gaze to remain fixed on a particular point even when we move our heads.
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