tangential view
| compression thrombosis | Thrombosis due to arrest of the circulation in a vessel by compression, as from a tumour. (05 Mar 2000) |
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| compression wave | <radiobiology> Waves where the quantity which oscillates is the density of the medium, that is the medium at a given point alternately compresses and expands. Low-amplitude compression waves in air or water are commonly known as sound waves, shock waves are a high-amplitude form. Synonym: density wave. (13 Jan 1998) |
| heat of compression | Heat produced when a gas is compressed. (05 Mar 2000) |
| spinal cord compression | A condition in which pressure is exerted on the spinal cord, as by a tumour, spinal fracture, etc. Its manifestations, which vary with location and degree of pressure, may include pain, paresthesias, and sensory and motor disturbances. (12 Dec 1998) |
| nerve compression syndromes | Repeated or prolonged pressure on a nerve root or peripheral nerve leading to ischemia, the response to which is oedema above and below the source of pressure. If the pressure is not relieved, fibrosis tends to develop. Types of nerve compression syndromes are the neuropathy caused by intervertebral disk herniation, compression of the median nerve in the carpal tunnel, compression of the ulnar nerve in the elbow, and compression of the lateral cutaneous nerve of the thigh in meralgia paresthetica. This is also called pressure neuropathy. (12 Dec 1998) |
| eyeball compression reflex | Slowing of the heart rate due to the vagal effects of compressing an eyeball. Synonym: eyeball compression reflex. (05 Mar 2000) |
| ulnar nerve compression syndrome | <syndrome> A condition caused by compression or entrapment of the ulnar nerve. It may involve both sensory and motor problems and most often results from compression or entrapment of the ulnar nerve at the elbow (cubital tunnel syndrome). Compression of the nerve may occur during normal activities or as a complication of general anaesthesia. (12 Dec 1998) |
| age spot | <dermatology> A skin disorder seen with aging (or sun exposure) where there are flat patches of increased pigmentation on the skin. They are nonserious, benign and generally more important cosmetically. The most commonly appear on sun exposed areas such as the forehead and the back of the hands. Avoidance of the sun and the use of a sunscreen (SPF of 15) can reduce the incidence of these lesions. Creams and lotions are available which bleach the skin. Cryotherapy can be used in some cases. (27 Sep 1997) |
| blind spot | The negative scotoma in the visual field, corresponding to the optic disk. Synonym: blind spot. (05 Mar 2000) |
| blue spot | A bluish stain on the skin caused by the bites of fleas or lice, especially pediculosis pubis. Synonym: blue spot, tache bleuatre. (05 Mar 2000) |
| cafe-au-lait spot | <dermatology> A pigmented cutaneous lesion, that can range from light to dark brown, and is due to an excess of melanosomes in the malpighian cells, rather than to an excess of melanocytes. Caf |
| Mariotte's blind spot | The portion of the optic nerve seen in the fundus with the ophthalmoscope. It is formed by the meeting of all the retinal ganglion cell axons as they enter the optic nerve. Because the retina at the optic disk has no photoreceptors there is a corresponding blind spot in the visual field. (12 Dec 1998) |
| cherry-red spot | The ophthalmoscopic appearance of the normal choroid beneath the fovea centralis, appearing as a red spot surrounded by white retinal oedema in central artery closure or lipid infiltration in sphingolipidosis. Synonym: Tay's cherry-red spot. (05 Mar 2000) |
| cherry-red spot myoclonus syndrome | <syndrome> A neuronal storage disorder in children characterised by a cherry red spot at the macula, progressive myoclonus, and easily controlled seizures; the result of sialidase deficiency. Type 1 is characterised by normal body habitus, cherry red macula, myoclonus, and normal beta-galactosidase levels; type 2 by short stature, bony abnormalities, and deficient beta-galactosidase. Synonym: sialidosis. (05 Mar 2000) |
| mongolian spot | <dermatology> A benign bluish or bruised-appearing birthmark that is usually located on the lower back or buttocks. More common in dark-skinned races and may persist for months to years. (27 Sep 1997) |