Cerebr: From 1 Different Sources
(cerebri-, cerebro-) combining form denoting the cerebrum or brain.
See STROKE.... cerebrovascular accident
Bleeding within the brain due to a ruptured blood vessel (see intracerebral haemorrhage; stroke).... cerebral haemorrhage
The largest and most developed part of the brain, the site of most conscious and intelligent activities. Its main components are 2 large cerebral hemispheres that grow out from the upper part of the brainstem. Their surface is made up of a series of folds called gyri, separated by fissures called sulci, with a deep longitudinal fissure separating the 2 hemispheres. The 4 main surface regions of each hemisphere – the frontal, parietal, temporal, and occipital lobes – are named after their overlying bones. Each hemisphere has a central cavity, called a ventricle, filled with cerebrospinal fluid. This is surrounded by an inner layer, consisting of clusters of nerve cells called the basal ganglia. A middle layer of “white matter” is composed mainly of nerve fibres, which carry information between specific areas of the cortex and between areas of the cortex, central brain, and the brainstem. A thick band of fibres
called the corpus callosum carries nerve signals between the 2 hemispheres.
The outer surface layer of each hemisphere is the cerebral cortex – the “grey matter’’, where much of the sensory information from organs such as the eyes and ears is processed. Specific sensory processing takes place in separate regions. For example, visual perception is located in a part of the occipital lobe called the visual cortex.
The cortex also contains “motor’’ areas concerned with the initiation of signals for movement by the skeletal muscles.
Linked to the sensory and motor areas of the cortex are association areas, which integrate information from various senses and also perform functions such as comprehension and recognition, memory storage and recall, thought and decision making.
Some of these cortical functions are localized to one “dominant’’ hemisphere (the left in almost all right-handed and many left-handed people).
Two clearly defined areas in the dominant hemisphere are Wernicke’s area, responsible for the comprehension of words, and Broca’s area, which is concerned with language expression.... cerebrum
See BRAIN.... cerebellum and cerebrum
Any disorder of the brain... cerebropathy
a collection of granules of calcium-containing material that is sometimes found within the *pineal gland as its calcification proceeds (normally after the 17th year): ‘brain sand’.... acervulus cerebri
see abscess.... cerebral abscess
(aqueduct of Sylvius) the narrow channel, containing cerebrospinal fluid, that connects the third and fourth *ventricles of the brain.... cerebral aqueduct
one of the two paired halves of the *cerebrum.... cerebral hemisphere
the intricately folded outer layer of the *cerebrum, making up some 40% of the brain by weight and composed of an estimated 15 thousand million neurons (see grey matter). This is the part of the brain most directly responsible for consciousness, with essential roles in perception, memory, thought, mental ability, and intellect, and it is responsible for initiating voluntary activity. It has connections, direct or indirect, with all parts of the body. The folding of the cortex provides a large surface area, the greater part lying in the clefts (sulci), which divide the upraised convolutions (gyri). On the basis of its microscopic appearance in section, the cortex is mapped into *Brodmann areas; it is also divided into functional regions; including *motor cortex, *sensory cortex, and *association areas. Within, and continuous with it, lies the *white matter, through which connection is made with the rest of the nervous system.... cerebral cortex
an abnormal multiplication of brain cells. Any tumorous swelling tends to compress or even destroy the healthy brain cells surrounding it and – because of the rigid closed nature of the skull – increases the pressure on the brain tissue. Malignant brain tumours, which are much more common in children than in adults, include *medulloblastomas and *gliomas; these grow rapidly, spreading through the otherwise normal brain tissue and causing progressive neurological disability. Benign tumours, such as *meningiomas, grow slowly and compress the brain tissue. Both benign and malignant tumours commonly cause fits. Benign tumours are often cured by total surgical resection. Malignant tumours may be treated by neurosurgery, chemotherapy, and radiotherapy, but the outcome for most patients remains poor.... cerebral tumour
the presence of thrombosis in the dural venous sinuses, which drain blood from the brain. Symptoms may include headache, abnormal vision, any of the symptoms of stroke (such as weakness of the face and limbs on one side of the body), and seizures. Treatment is with anticoagulants.... cerebral venous sinus thrombosis
n. 1. the functioning of the brain as a whole. 2. the unconscious activities of the brain.... cerebration
n. one of a group of compounds occurring in the *myelin sheaths of nerve fibres. They are *glycolipids, containing a sphingolipid bound to a sugar, usually galactose (in galactocerebrosides) or glucose (in glucocerebrosides).... cerebroside
(spotted fever) see meningitis.... cerebrospinal fever
see idiopathic intracranial hypertension.... pseudotumour cerebri
pertaining to the largest part of the brain, the cerebrum.... cerebral
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