Cerebral cortex Health Dictionary

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Cerebral Cortex: From 1 Different Sources

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.
Health Source: Oxford | Concise Colour Medical Dictionary
Author: Jonathan Law, Elizabeth Martin

Cerebral Palsy

The term used to describe a group of conditions characterised by varying degrees of paralysis and originating in infancy or early childhood. In some 80 per cent of cases this takes the form of spastic paralysis (muscle sti?ness), hence the now obsolete lay description of sufferers as ‘spastics’. The incidence is believed to be around 2 or 2·5 per 1,000 of the childhood community. In the majority of cases the abnormality dates from well before birth: among the factors are some genetic malformation of the brain, a congenital defect of the brain, or some adverse e?ect on the fetal brain as by infection during pregnancy. Among the factors during birth that may be responsible is prolonged lack of oxygen such as can occur during a di?cult labour; this may be the cause in up to 15 per cent of cases. In some 10–15 per cent of cases the condition is acquired after birth, when it may be due to KERNICTERUS, infection of the brain, cerebral thrombosis or embolism, or trauma. Acute illness in infancy, such as meningitis, may result in cerebral palsy.

The disease manifests itself in many ways. It may not be ?nally diagnosed and characterised until the infant is two years old, but may be apparent much earlier – even soon after birth. The child may be spastic or ?accid, or the slow, writhing involuntary movements known as athetosis may be the predominant feature. These involuntary movements often disappear during sleep and may be controlled, or even abolished, in some cases by training the child to relax. The paralysis varies tremendously. It may involve the limbs on one side of the body (hemiplegia), both lower limbs (paraplegia), or all four limbs (DIPLEGIA and QUADRIPLEGIA). Learning disability (with an IQ under 70) is present in around 75 per cent of all children but children with diplegia or athetoid symptoms may have normal or even high intelligence. Associated problems may include hearing or visual disability, behavioural problems and epilepsy.

The outlook for life is good, only the more severely affected cases dying in infancy. Although there is no cure, much can be done to help these disabled children, particularly if the condition is detected at an early stage. Assistance is available from NHS developmental and assessment clinics, supervised by community paediatricians and involving a team approach from experts in education, physiotherapy, occupational therapy and speech training. In this way many of these handicapped children reach adulthood able to lead near-normal lives. Much help in dealing with these children can be obtained from SCOPE (formerly the Spastics Society), and Advice Service Capability Scotland (ASCS).... cerebral palsy

Cortex

The tissues that form the outer part of an organ and which are positioned just below the capsule or outer membrane. Examples are the cerebal cortex of the BRAIN and the renal cortex of the KIDNEYS.... cortex

Sensory Cortex

See BRAIN.... sensory cortex

Cerebral Thrombosis

Formation of a blood clot within vessels of the brain. May be due to atheroma or embolism causing a blockage resulting in hypoxia (oxygen deficiency).

Alternatives. Teas. Lime flowers, Nettles, Horsetail, Ginkgo, Oats, Mistletoe, Yarrow.

Tea. Mix equal parts: Ginkgo, Hawthorn, Yarrow. One heaped teaspoon to each cup boiling water; infuse 5-10 minutes; 1 cup thrice daily.

Tablets/capsules. Ginkgo, Hawthorn, Prickly Ash.

Diet. See: DIET–HEART AND CIRCULATION.

Supplements. Daily: Vitamin E 1000mg; B6 50mg; B12 2mcg. Selenium 200mcg; Zinc 15mg. Strict bedrest; regulate bowels; avoid excessive physical and mental exertion. ... cerebral thrombosis

Cerebral Haemorrhage

Bleeding within the brain due to a ruptured blood vessel (see intracerebral haemorrhage; stroke).... cerebral haemorrhage

Adrenal Cortex

The outer covering of the two adrenal glands that lie atop each kidney. Embryonically derived from gonad tissue, they make steroid hormones that control electrolytes, the management of fuels, the rate of anabolism, the general response to stress, and maintenance of nonspecific resistance.... adrenal cortex

Cerebral Abscess

see abscess.... cerebral abscess

Cerebral Aqueduct

(aqueduct of Sylvius) the narrow channel, containing cerebrospinal fluid, that connects the third and fourth *ventricles of the brain.... cerebral aqueduct

Cerebral Hemisphere

one of the two paired halves of the *cerebrum.... cerebral hemisphere

Cerebral Venous Sinus Thrombosis

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

Motor Cortex

the region of the *cerebral cortex that is responsible for initiating nerve impulses that bring about voluntary activity in the muscles of the body. It is possible to map out the cortex to show which of its areas is responsible for which particular part of the body. The motor cortex of the left cerebral hemisphere is responsible for muscular activity in the right side of the body.... motor cortex

Cerebral

pertaining to the largest part of the brain, the cerebrum.... cerebral

Cerebral Tumour

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

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