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 pineal gland is located deep in the brain and attached by a stalk to the top of the third ventricle.
The pineal gland responds to light and dark and secretes melatonin, which regulates circadian rhythms and the sleep-wake cycle. Deep in the brain are four open areas with passageways between them. They also open into the central spinal canal and the area beneath arachnoid layer of the meninges. The ventricles manufacture 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 cushions the spinal cord and brain, washes out waste and impurities, and delivers nutrients.
Two sets of blood vessels supply blood and oxygen to the brain: the vertebral arteries and the carotid arteries. The external carotid arteries extend up the sides of your neck, and are where you can feel your pulse when you touch the area with your fingertips.
The internal carotid arteries branch into the skull and circulate blood to the front part of the brain. The vertebral arteries follow the spinal column into the skull, where they join together at the brainstem and form the basilar artery , which supplies blood to the rear portions of the brain. The circle of Willis , a loop of blood vessels near the bottom of the brain that connects major arteries, circulates blood from the front of the brain to the back and helps the arterial systems communicate with one another.
The first two nerves originate in the cerebrum, and the remaining 10 cranial nerves emerge from the brainstem, which has three parts: the midbrain, the pons and the medulla.
Health Home Conditions and Diseases. What is the brain made of? What is the gray matter and white matter? How does the brain work? Main Parts of the Brain and Their Functions At a high level, the brain can be divided into the cerebrum, brainstem and cerebellum.
Cerebrum The cerebrum front of brain comprises gray matter the cerebral cortex and white matter at its center. Brainstem The brainstem middle of brain connects the cerebrum with the spinal cord. The midbrain or mesencephalon is a very complex structure with a range of different neuron clusters nuclei and colliculi , neural pathways and other structures. These features facilitate various functions, from hearing and movement to calculating responses and environmental changes.
The pons is the origin for four of the 12 cranial nerves, which enable a range of activities such as tear production, chewing, blinking, focusing vision, balance, hearing and facial expression. At the bottom of the brainstem, the medulla is where the brain meets the spinal cord. The medulla is essential to survival. A critical component of the limbic system is the amygdala, which is an almond shaped set of neurons responsible for the processing of fear. The connection between fear and the amygdala can be traced back to research by Heinrich Kluver and Paul Bucy in the s, who removed the amygdalae in rhesus monkeys and found them to display little fear Hayman et al.
Another important part of the limbic system is the hippocampus , which is responsible for long-term memory formation. Henry Gustave Molaison, known as H. As a result, he suffered from severe anterograde amnesia: an inability to form new memories. There are two other major structures of the limbic system worth mentioning: the thalamus and hypothalamus. The thalamus is considered to be the neural railway station of the brain. Sensory input from the body travels to the thalamus, where it is then relayed to the rest of the brain as a specific sensation.
The thalamus is also involved with consciousness, alertness, and sleep Mandal, Located between the two halves of the thalamus is the pineal gland: a pea-shaped gland that regulates sleep. Its other functions are not yet fully understood. The hypothalamus is located at the base of the brain near the pituitary gland, and it is involved with pleasure, food, body temperature, and sex Seladi-Schulman, If body temperature gets too high, the hypothalamus instructs the body to sweat.
If the body is cold, the hypothalamus will cause shivers. Irregular hypothalamic behavior can in turn lead to sweating and shivering when these reactions are not needed. The hypothalamus also regulates the pituitary gland, regulates the other hormone releasing glands in the body.
The second area of the brain is the midbrain, which lies on top of the brainstem. The midbrain is involved in auditory and visual processing Peters, It is also responsible for eye movement.
There are three parts to the midbrain: the colliculi, the tegmentum, and the cerebral peduncles. The colliculi processes visual and auditory signals before they are relayed to the occipital and temporal lobes.
The tegmentum is involved in movement coordination and alertness. Lastly, the cerebral peduncles plays an important part in the central nervous system. The hindbrain is located at the back of the head and looks like an extension of the spinal cord.
It contains the medulla oblongata, pons, and cerebellum collectively known as the brainstem. The medulla oblongata, also simply known as the medulla, is the lowest part of the brainstem and the primary connection to the nervous system. It is primarily involved in breathing, heart rate, digestion, swallowing, heart rhythms, and sneezing Peters, The medulla controls the automatic processes of the autonomic nervous system , such as breathing, blood pressure, and heart rate.
The cerebellum is also thought to be an important area for processing procedural memory. Most disorders of the cerebellum are associated with serious motor impairment. He enjoys studying the intersection of Economics, Psychology, and Philosophy. Eid, D. It is important within the formation of memories and in making decisions and learning. The thalamus has many functions including processing and relaying sensory information selectively to various parts of the cerebral cortex, translating signals to the cerebral cortex from lower centers including auditory, somatic, visceral, gustatory, and visual systems, and also regulating states of sleep and wakefulness.
The thalamus plays a serious role in regulating arousal, levels of consciousness, and levels of activity. The function of the hypothalamus is especially associated with the general regulation of the system. The hypothalamus is closely associated with the pituitary, controlling an outsized proportion of the activity getting to it. The main function of the pituitary is related to the production of hormones as it is the part of the Endocrine System. The cerebral cortex is necessary for the memory storage, attention, awareness, thought, language and consciousness.
The outer layers of the cerebrum are made from gray matter. Grey matter is formed by neurons and their unmyelinated fibers. The white matter below the grey matter of the cortex is formed predominantly by myelinated axons. The surface of the cerebral cortex is folded in mammals; more than two-thirds of the surface is within the grooves or "sulci''. The cerebral cortex is connected to structures such as the thalamus and the basal ganglia, sending information to them along with different connections and receiving information from them via afferent connections.
Most sensory information is routed to the cerebral mantle via the thalamus. The cortex is commonly described as comprising three parts; sensory, motor, and association areas. The forebrain, midbrain, and hindbrain structure the three major parts of the brain.
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