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Definition

field

(fēld )

  1. In geography, an open expanse of land .
  2. In the arts and sciences, a discipline or an area of study.
  3. In physics, a region of space in which a given force operates or a given condition exists.
  4. In experimental situations, a place of natural conditions, as opposed to a controlled environment, such as a laboratory or a hospital.

auditory f.The spatial region in which a given person can hear sounds.

cortical f.A segment of the cerebral cortex that carries out a given function. For example, the postcentral gyrus (the front of the parietal lobe) can be called a primary somatosensory field; and the parietal cortex farther back, an association field.

dry f.A colloquial term for a bloodless surgical field in which the surgeon's vision is not obscured.

electric f.The region in space in which the attractive or repulsive effects of a given electric charge have an effect.

electromagnetic f.

ABBR: EMF

The region in space in which the photons produced by moving electric charges have an effect. EMFs can be produced by power lines, radio waves, and microwaves. The energy produced in an EMF increases as the frequency of the photons increases, and EMFs produced by very high frequency photons, e.g., x-rays and gamma rays, are sufficiently energetic to induce cancer.

eye f.Any region of the cortex concerned with sensation from or movement of an eye.

far f.In medical imaging, the region of the body furthest from the source of electromagnetic energy.

f. of fixation The widest limits of vision in all directions within which the eyes can fixate.

f. of Forel One of the layers of axons, many originating in the globus pallidus, that form the lower (inferior) border of the thalamus in the brain. Together, the axons and neighboring neurons are known as the subthalamic reticular nucleus. SYN: prerubral field.

free f.A space in which there are no surfaces that reflect specific frequencies of sound.

fringe f.Magnetized space that surrounds the imaging core of a magnetic resonance imaging scanner.

gradient-induced electric f.An electric field that may surround an object placed in a rapidly changing magnetic environment, such as one generated by a magnetic resonance imaging device.

gravitational f.The region in space in which the attractive effects of a given mass have an effect.

hand f.Any region of the cortex concerned with sensation from or movement of a hand .

heart f.The region of the embryo destined to produce the heart.

high-power f.The portion of an object seen when the high-magnification lenses of a microscope are used.

hippocampal f.Any of the three contiguous, but histologically distinguishable, sheets of cells that form the cortex of the hippocampus; the fields are usually called CA1, CA2, and CA3.

involved f.A radiographically defined region of the body in which a tumor is located.

low-power f.The portion of an object seen when the low-magnification lenses of a microscope are used.

lung f.The region in the body containing a lung. The term often refers to the section of a medical image (such as a chest x-ray) that shows a lung.

magnetic f.The space permeated by the magnetic lines of force surrounding a permanent magnet or coil of wire carrying electric current.

near f.In medical imaging, the region of the body closest to the source of electromagnetic energy.

prerubral f.Field of Forel.

pulsing electromagnetic f.

ABBR: PEMF

An alternating electrical current used to produce an electromagnetic field. This may induce healing when applied to a fractured bone. The field is applied noninvasively to the affected limb. It may be moderately helpful in treating bony nonunion.

SEE: diathermy.

receptive f.A description of the effective stimuli of a given neuron. For sensory receptor neurons, the receptive field is the type of effective stimulation, e.g., light, sound, mechanical pressure, and the range of sensitive locations, e.g., center of visual field, left auditory field, tip of right thumb.

sterile f.A body surface, along with surrounding drapes or towels, within which an operation may safely take place without introducing potentially hazardous microorganisms into a patient.

The field is prepared by meticulously washing and scrubbing the patient on whom an operation will be performed with disinfectant solution. Sterile drapes and towels are placed over the patient to cover any unprepared skin or clothing with sterilized fabric. All surgical instruments that enter the operative theater are cleansed according to decontamination and sterilization practices. Finally, all surgical personnel scrub for prescribed time periods with disinfectants before entering the operating room. They must wear sterile gloves, gowns, masks, and shoe covers and replace these if any of them contact nonprepared items during surgery.

surgical f.The area in which an operation is performed. This field is prepared and covered to maintain sterility during operations.

useful f. of view

ABBR: UFOV

A test of visual attention that measures the space in which an individual can receive information rapidly from two separate sources. It is a strong predictor of accidents in older drivers. Training can expand the useful field of view and increase the visual processing speed of an older person.

f. of view Visual field.

f. of vision Visual field.

visual f.The area within which objects may be seen when the eye is fixed. SYN: field of view; field of vision.

SEE: illus.; perimetry.