Free field audiogram Health Dictionary

A graph produced during hearing tests (with an audiometer) that shows the hearing threshold – the minimal audible loudness level – for a range of sound frequencies.... audiogram

A psychoanalytic technique in which the therapist encourages the patient to follow up a speci?c line of thought and ideas as they enter his or her consciousness.... free association

Both vegetable and animal tissues produce free radicals as a normal metabolic byproduct. They are found in many areas of human activity.

A radical is a group of atoms which can combine in the same way as single atoms to make a molecule. Free means uncombined. A free radical is a state in which a radical can exist before it combines – an incomplete molecule containing oxygen which has an uneven electrical charge. High energy oxygen atoms are known to form atheroma.

As well as being substances that take part in a process of metabolism, free radicals can be found in industrial fumes and cigarette smoke. They are oxidants and have an anti-bacterial effect. But their activity is not confined to bacteria alone. When produced in large amounts as in inflammation and infection, they may have a damaging effect upon the lining of blood vessels and other tissues. An excess is produced in ischaemic heart disease. They have been shown to be involved in jet lag, Alzheimer’s disease, rheumatoid arthritis, thrombosis, heart failure, cancer, irradiation sickness and a weak immune system. Damaging to the DNA, they are probably the greatest single cause of ill health. They hasten the ageing process. Vitamins A, C, E, being antioxidants and the mineral Selenium stimulate certain enzyme systems to limit damage done by these destructive elements.

Losing weight is believed to generate free radicals – a metabolic side-effect of dieting. See: ANTIOXIDANTS. ... free radicals

Vague apprehension or tension, often associated with generalized anxiety disorder.... free-floating anxiety

The total area in which visual perception is possible while a person is looking straight ahead.

The visual fields normally extend outwards over an angle of about 90 degrees on either side of the midline of the face, but are more restricted above and below, especially if the eyes are deep-set or the eyebrows are prominent.

The visual fields of the 2 eyes overlap to a large extent, giving binocular vision.

Partial loss of the visual field may occur in glaucoma or stroke.... visual field

When the eye looks at a speci?c point or object, that point is seen clearly. Other objects within a large area away from this ?xation point can also be seen, but less clearly. The area that can be seen around the ?xation point, without moving the eye, is known as the ?eld of vision. The extent of the ?eld is limited inwards by the nose, above by the brow and below by the cheek. The visual ?eld thus has its greatest extent outwards from the side of the head. The ?eld of vision of each eye overlaps to a large extent so that objects in the centre and towards the inner part of each ?eld are viewed by both eyes together. Because the eyes are set slightly apart, each eye sees objects in this overlapping part of the ?eld slightly di?erently. It is because of this slight di?erence that objects can be perceived as three-dimensional.

Defects in the visual ?eld (scotomas) can be produced by a variety of disorders. Certain of these produce speci?c ?eld defects. For example, GLAUCOMA, some types of brain damage and some TOXINS can produce speci?c defects in the visual ?eld. This type of ?eld defect may be very useful in diagnosing a particular disorder. The blind spot is that part of the visual ?eld corresponding to the optic disc. There are no rods nor cones on the optic disc and therefore no light perception from this area. The blind spot can be found temporal (i.e. on the outer side) of the ?xation point. (See also EYE.)... vision, field of

Some people cannot absorb the protein gluten present in wheat, barley, rye and oats, and hundreds of foods made from them. Nutritional deficiencies may result in coeliac disease, schizophrenia, allergies and irritable bowel syndrome.

Foods containing gluten include: many breakfast cereals, shredded wheat, wheat germ flakes, white and wholemeal bread, cakes, puddings, biscuits, porridge, rye and wheat crispbreads, crumbled fish and meat, semolina, baked beans, macaroni, baby foods, soups in packets and tins, chocolate, cocoa, spaghetti, muesli, custard, sausages, batter, beer, instant coffee, bedtime drinks and all kinds of pasta.

Natural gluten-free foods include maize, peas, millet, Soya, lima beans, rice. Brown rice is the basic cereal food: cornflakes, puffed rice, rice cereals. Millet flakes, sago, tapioca. These may be prepared in skimmed milk. Gluten-free flours and bread. The potato comes into its own in the gluten-free kitchen, especially for thickening soups and casseroles.

One school of medical thought associates certain nerve dyscrasies with nutritional deficiencies, the gluten-free diet being advised for cases of multiple sclerosis, myasthenia gravis, poliomyelitis, syringomyelia, motor neurone disease.

Book. Gluten-Free cooking Recipes for Coeliacs and Others, by Rita Greer. ... diet - gluten-free

see visual field.... field of vision

the radiographic finding of gas where it would not normally be expected, particularly in the peritoneal cavity. It is typically associated with perforation of a hollow organ containing gas, usually the bowel.... free gas

(PTA) see audiogram.... pure tone audiogram

n. (in radiotherapy) an area of the body selected for treatment with radiotherapy. For example, a mantle field comprises the neck, armpits, and central chest, for the radiotherapy of Hodgkin’s disease. Radiation is administered to the defined area by focusing the beam of particles emitted by the radiotherapy machine and shielding the surrounding area of the body.... treatment field

(transvaginal tape, TVT) a surgical sling procedure for treating stress incontinence in women that uses a tape made of polypropylene mesh. The tape is inserted under the mid-urethra (rather than the bladder neck, as in a *pubovaginal sling), passing through the retropubic space on either side, and is fixed to the abdominal wall just internal to the pubic symphysis. The transobturator tape (TOT) procedure is similar, but in this technique a tunnel is created out to the *obturator foramen on either side, lessening the risk of vascular and bladder injuries. Tape procedures have lower morbidity rates than *colposuspension and have gradually replaced the latter as the surgical procedure of choice for treating female stress incontinence, but there may be complications associated with nonabsorbable mesh.... tension-free vaginal tape