Brain is the most complex and delicate organ of human body. Though it weighs about 1.4 kg, it contains approximately a hundred billion nerve cells. The nervous system comprises brain, spinal cord and sensory nerves and it is the most complicated human body system. The brain is made up of three major regions fore-brain, mid-brain and hind-brain and each region consists of different interdependent parts.
Major Brain Regions
The fore-brain is the largest part of the brain which consists of the cerebrum, thalamus and the hypothalamus. The cerebrum is further divided into two hemispheres, the right hemisphere and the left hemisphere. Right brain functions and left brain functions are described below.
The most interesting fact about brain regions and their functions is that right side of the brain controls the physical activities performed by the left half of the body and the left half of the brain controls the activities performed by the right side of the body. It is believed that the left hemisphere is involved in language and creativeness, while the right side of the brain takes care of understanding and judgment. Human brain facts inform us that the left brain is responsible for the personality and the right for the intelligence. Apart from cerebrum, the fore-brain also contains thalamus and hypothalamus (part of the limbic system).
The mid-brain or the mesencephalon is situated behind the frontal lobes and occupies the centre of the entire brain. Hearing, vision, body and eye movements are controlled by mid-brain. The mid-brain is again subdivided into three parts called the tectum, tegmentum and cerebral peduncles.
Hind-brain, as the name suggests, is the posterior part of the brain that consists of cerebellum, pons and medulla and the hind-brain along with pons and medullas is also known as brain stem.
Main Functions of Brain Regions
- Cerebral Cortex: The outermost layer of the cerebral hemisphere, made up of gray matter is involved in the functions of learning new information, forming thoughts, making decisions, analyzing sensory data and performing memory functions.
- Corpus Callosum: Connects right and left hemisphere and allows communication between the two hemispheres. Provides roof to the lateral and third ventricles.
- Frontal Lobe: Memory and cognition. Enables you to concentrate and attend, makes you capable of elaboration of thought, judgment, inhibition. Thus involved in personality development and emotional traits. Also helps in voluntary motor activity and motor speech.
- Parietal Lobe: Processing of sensory input, sensory discrimination. Helps in body orientation.
- Occipital Lobe: Concerned with primary visual reception area and primary visual association area which allow for visual interpretation.
- Temporal Lobe: Rules over auditory receptive area and association areas. It takes care of expressed behaviour, receptive speech and information retrieval.
- Limbic System: Manages olfactory pathways, amygdale and their different pathways, hippocampus and their different pathways. Limbic lobes control the functions related to sex, rage, fear emotions. The system is responsible for integration of recent memory, biological rhythms.
- Basal Ganglia: These are the subcortical gray matter nuclei which act as processing link between thalamus and motor cortex. Their functions include initiation and direction of voluntary movement, balance (inhibitory), postural reflexes, regulation of automatic movement.
- Thalamus: Sends the incoming sensory nerve impulses to the required appropriate regions of the brain for further processing. Most sensory signals, like auditory signals, visual signals and somatosensory signals pass through this relay station before being further interpreted in the brain. Its main function is providing the brain information on what is happening outside the body. Other functions include motor control, and control of muscular movements.
- Hypothalamus: Integration centre of Autonomic Nervous System. It helps regulate body temperature and endocrine functions. It regulates various sensations, such as hunger, thirst, libido and is responsible for maintaining the daily sleep and wake cycle. It also controls emotions, autonomic functions and motor functions and maintains homeostasis by exerting control on the pituitary gland.
- Internal Capsule: Motor tracts. Dysfunction leads to paralysis of the opposite side of the body.
- Reticular Activating System: Responsible for arousal from sleep, wakefulness, attention. Dysfunction may lead to altered level of consciousness.
- Cerebellum: Coordinates and controls voluntary movement, maintains balance and equilibrium while walking, swimming, riding, etc., stores memory for reflex motor acts, coordinates simultaneous subconscious actions, like eating while talking or listening etc.
- Mid-brain: Contains auditory and visual reflex centres. It is responsible for the reflex movements of the muscles of the head, neck and the eye and provides a passage for different neurons going in and coming out of the cerebrum.
- Pons: Respiratory Centre. Has control over skin of face, tongue, teeth, muscle of mastication, muscle of eye which rotates eye outward, facial muscles of expression, internal auditory passage. It plays an important role in the level of arousal or consciousness and sleep and is involved in controlling autonomic body functions.
- Medulla Oblongata: It contains the cardiac, respiratory and vasomotor centres and executes the most important function of the brain that is, regulating our life processes such as breathing, maintaining a steady heart rate and blood pressure, inciting regurgitation (vomiting), swallowing, urination, defecation and in coordinating lifesaving reflexes.
There are some specially designed brain exercises which you may perform to enhance the power of your brain. Healthy diet
, sufficient rest, regular exercise, good eating and sleeping habits play an important role in the health of the brain. Insufficient supply of blood to the brain, even for a few seconds or minutes can destroy the health of several organs.