What is the brain?
The brain is a complex organ that controls thought, memory, emotion, touch, motor skills, vision, breathing, temperature, hunger and every procedure that regulates ours body. Together, the brain and spinal cord that extends indigenous it make up the main nervous system, or CNS.
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What is the mind made of?
Weighing about 3 pounds in the median adult, the brain is about 60% fat. The continuing to be 40% is a mix of water, protein, carbohydrates and salts. The brain itself is a no a muscle. It consists of blood vessels and nerves, including neurons and glial cells.
What is the gray matter and white matter?
Gray and white issue are two various regions the the central nervous system. In the brain, gray issue refers to the darker, outer portion, if white matter defines the lighter, inner section underneath. In the spinal cord, this bespeak is reversed: The white matter is top top the outside, and also the gray matter sits within.
Gray issue is mostly composed that neuron somas (the round central cell bodies), and also white issue is largely made of axons (the long stems that connects neurons together) covering in myelin (a safety coating). The various composition that neuron components is why the two show up as separate shades on specific scans.
Each an ar serves a different role. Gray issue is mainly responsible for processing and interpreting information, when white matter transmits that information to other parts of the concerned system.
How walk the mind work?
The mind sends and receives chemical and electrical signal throughout the body. Different signals manage different processes, and also your brain interprets each. Some make you feel tired, for example, if others do you feeling pain.
Some messages are retained within the brain, while others are relayed through the spine and across the body’s huge network of nerves to remote extremities. To carry out this, the main nervous mechanism relies ~ above billions of neurons (nerve cells).
Main parts of the brain and their Functions
At a high level, the mind can be split into the cerebrum, brainstem and also cerebellum.
The cerebrum (front that brain) comprises gray issue (the cerebral cortex) and also white matter at that center. The largest component of the brain, the cerebrum initiates and also coordinates movement and regulates temperature. Other locations of the cerebrum allow speech, judgment, thinking and also reasoning, problem-solving, emotions and also learning. Other features relate to vision, hearing, touch and other senses.Cerebral Cortex
Cortex is Latin because that “bark,” and describes the external gray matter covering that the cerebrum. The cortex has actually a large surface area due to its folds, and also comprises about fifty percent of the brain’s weight.
The cerebral cortex is split into 2 halves, or hemispheres. The 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) the runs native the former of the head come the back. The right hemisphere controls the left side of the body, and also the left half controls the right side of the body. The two halves interact with one one more through a large, C-shaped structure of white matter and nerve pathways dubbed the corpus callosum. The body callosum is in the center of the cerebrum.
The brainstem (middle the brain) associate the cerebrum with the spinal cord. The brainstem includes the midbrain, the pons and the medulla.Midbrain. The midbrain (or mesencephalon) is a very facility structure v a range of various neuron swarm (nuclei and colliculi), neural pathways and also other structures. These features facilitate miscellaneous functions, indigenous hearing and also movement come calculating responses and also environmental changes. The midbrain additionally contains the substantia nigra, one area impacted by Parkinson’s an illness that is well-off in dopamine neurons and component of the basal ganglia, which enables movement and also coordination. Pons. The pons is the origin for four of the 12 cranial nerves, which enable a selection of tasks such together tear production, chewing, blinking, focusing vision, balance, hearing and also facial expression. Named for the Latin word because that “bridge,” the pons is the connection between the midbrain and also the medulla. Medulla. At the bottom the the brainstem, the medulla is wherein the brain meets the spinal cord. The medulla is vital to survival. Attributes of the medulla regulate countless bodily activities, consisting of heart rhythm, breathing, blood flow, and oxygen and carbon dioxide levels. The medulla produces reflexive tasks such as sneezing, vomiting, coughing and swallowing.
The spinal cord extends from the bottom that the medulla and also through a large opening in the bottom of the skull. Supported by the vertebrae, the spinal cord carries messages to and also from the mind and the rest of the body.
The cerebellum (“little brain”) is a fist-sized part of the brain located in ~ the back of the head, below the temporal and occipital lobes and above the brainstem. Like the cerebral cortex, it has actually two hemispheres. The outer part contains neurons, and also the inner area communicates v the cerebral cortex. Its duty is to name: coordinates voluntary muscle movements and to keep posture, balance and also equilibrium. Brand-new studies are exploring the cerebellum’s duties in thought, emotions and also social behavior, as well as its feasible involvement in addiction, autism and schizophrenia.
Brain Coverings: Meninges
Three class of protective covering called meninges surround the brain and the spinal cord.The outermost layer, the dura mater, is thick and also tough. It contains two layers: The periosteal layer of the dura mater lines the inner dome that the skull (cranium) and also the meningeal layer is listed below that. Spaces between the layers enable for the passage of veins and arteries that supply blood circulation to the brain. The arachnoid mater is a thin, weblike layer of connective organization that does no contain nerves or blood vessels. Below the arachnoid mater is the cerebrospinal fluid, or CSF. This liquid cushions the entire central nervous system (brain and spinal cord) and also continually circulates roughly these frameworks to eliminate impurities. The pia mater is a thin membrane the hugs the surface ar of the brain and complies with its contours. The pia mater is rich through veins and also arteries.
Lobes the the brain and What lock Control
Each mind hemisphere (parts of the cerebrum) has 4 sections, dubbed lobes: frontal, parietal, temporal and also occipital. Each lobe controls specific functions.
Deeper structures Within the Brain
Sometimes dubbed the “master gland,” the pituitary gland is a pea-sized structure uncovered deep in the brain behind the leg of the nose. The pituitary gland governs the function of various other glands in the body, regulation the circulation of hormone from the thyroid, adrenals, ovaries and also testicles. The receives chemical signal from the hypothalamus v its stalk and also blood supply.
The hypothalamus is located over the pituitary gland and also sends it chemistry messages that control its function. The regulates human body temperature, synchronizes sleep patterns, controls hunger and also thirst and also plays a duty in some aspects of memory and emotion.
Small, almond-shaped structures, one amygdala is situated under each fifty percent (hemisphere) of the brain. Consisted of in the limbic system, the amygdalae manage emotion and memory and also are associated with the brain’s prize system, stress, and the “fight or flight” solution when someone perceives a threat.
A curved seahorse-shaped organ on the underside of each temporal lobe, the hippocampus is component of a larger structure called the hippocampal formation. It support memory, learning, navigation and perception the space. That receives details from the cerebral cortex and may play a duty in Alzheimer’s disease.
The pineal gland is situated deep in the mind and attached by a stalk to the peak of the third ventricle. The pineal gland responds to light and dark and secretes melatonin, i m sorry regulates circadian rhythms and the sleep-wake cycle.
Ventricles and Cerebrospinal Fluid
Deep in the mind are four open locations with passageways in between them. They also open right into the main spinal canal and the area beneath arachnoid class of the meninges.
The ventricles to produce cerebrospinal fluid, or CSF, a watery fluid that circulates in and around the ventricles and the spinal cord, and between the meninges. CSF surrounds and also cushions the spinal cord and also brain, washes the end waste and impurities, and also delivers nutrients.
Blood it is provided to the Brain
Two set of blood vessels supply blood and also oxygen to the brain: the vertebral arteries and also the carotid arteries.
The outside carotid arteries prolong up the political parties of her neck, and are where you can feel her pulse once you touch the area with your fingertips. The interior carotid arteries branch right into the skull and circulate blood come the front component of the brain.
The vertebral arteries follow the spinal column right into the skull, wherein they join together in ~ the brainstem and kind the basilar artery, which supplies blood come the rear portions of the brain.
The circle of Willis, a loop that blood vessels close to the bottom of the brain that connects significant arteries, circulates blood from the former of the mind to the ago and help the arterial systems connect with one another.
Inside the cranium (the dome that the skull), there room 12 nerves, referred to as cranial nerves:Cranial nerve 1: The first is the olfactory nerve, which enables for your sense of smell. Cranial nerve 2: The optic nerve governs eyesight. Cranial nerve 3: The oculomotor nerve controls pupil response and other movements of the eye, and also branches the end from the area in the brainstem where the midbrain meets the pons. Cranial nerve 4: The trochlear nerve controls muscles in the eye. It increase from the ago of the midbrain component of the brainstem. Cranial nerve 5: The trigeminal nerve is the largest and most complex of the cranial nerves, v both sensory and motor function. That originates indigenous the pons and conveys emotion from the scalp, teeth, jaw, sinuses, parts of the mouth and also face come the brain, permits the function of chewing muscles, and also much more. Cranial nerve 6: The abducens nerve innervates some of the muscles in the eye. Cranial nerve 7: The facial nerve supports challenge movement, taste, glandular and also other functions. Cranial nerve 8: The vestibulocochlear nerve facilitates balance and hearing. Cranial nerve 9: The glossopharyngeal nerve permits taste, ear and also throat movement, and has many much more functions. Cranial nerve 10: The vagus nerve permits sensation about the ear and the cradle system and also controls motor task in the heart, throat and also digestive system. Cranial nerve 11: The accessory nerve innervates certain muscles in the head, neck and shoulder. Cranial nerve 12: The hypoglossal nerve offers motor task to the tongue.
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The first two nerves originate in the cerebrum, and the continuing to be 10 cranial nerves emerge from the brainstem, which has three parts: the midbrain, the pons and also the medulla.