| bell sound | In cases of a large pulmonary cavity or of pneumothorax, a clear metallic sound obtained by striking a coin, held against the chest, by another coin, or by flicking the chest wall with one's fingernail; the sound is heard on auscultating the chest wall on the same side anteroposteriorly. Synonym: anvil sound, bell sound, coin test. (05 Mar 2000) |
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| Bell's palsy | A condition that involves the facial nerve (VII cranial nerve) and results in the paralysis of one side of the face. Bell's (facial nerve palsy) can be differentiated from a central (stroke) deficit by the inability to raise the eyebrow on the affected side. (27 Sep 1997) |
| Bell's phenomenon | A patient with peripheral facial paralysis cannot close the eyelids of the affected side without at the same time moving the eyeball upward and outward. (05 Mar 2000) |
| Bell's respiratory nerve | <anatomy, nerve> Arises from the fifth, sixth, and seventh cervical nerves (roots of brachial plexus), descends the neck behind the brachial plexus, and is distributed to the serratus anterior muscle; it is somewhat unusual in that it courses on the superficial aspect of the muscle is supplies; its paralysis results in "winged scapula". Synonym: nervus thoracicus longus, Bell's respiratory nerve, external respiratory nerve of Bell, posterior thoracic nerve. (05 Mar 2000) |
| Bell's spasm | Involuntary twitching of the facial muscles, sometimes unilateral. Synonym: Bell's spasm, convulsive tic, facial spasm, histrionic spasm, mimic convulsion, mimic spasm, mimic tic, palmus, prosopospasm. (05 Mar 2000) |
| syndrome, martin-bell | Better known as the fragile X syndrome, the most common heritable form of mental retardation. Fragile x syndrome is due to mutation (changes) at the fragile x site and so perforce is x-linked (carried on the x chromosome). Although it is usually more severe in males than females, the syndrome is due to a dynamic mutation (a trinucleotide repeat) that can change in length and hence in severity from generation to generation, from person to person, and even within a given person. The fragile x syndrome is known as the martin-bell syndrome in honor of their discovery of it in 1943. (12 Dec 1998) |
| external respiratory nerve of Bell | <anatomy, nerve> Arises from the fifth, sixth, and seventh cervical nerves (roots of brachial plexus), descends the neck behind the brachial plexus, and is distributed to the serratus anterior muscle; it is somewhat unusual in that it courses on the superficial aspect of the muscle is supplies; its paralysis results in "winged scapula". Synonym: nervus thoracicus longus, Bell's respiratory nerve, external respiratory nerve of Bell, posterior thoracic nerve. (05 Mar 2000) |
| algid stage | The stage of collapse in cholera. (05 Mar 2000) |
| bacteria-free stage of bacterial endocarditis | Endocarditis described prior to the antibiotic era and presumably due to spontaneous healing of the bacterial vegetations. (05 Mar 2000) |
| bud stage | First stage of tooth development; development of the primordia of the enamel organs, the tooth buds. (05 Mar 2000) |
| cap stage | Second stage of tooth development wherein there is development of the inner and outer enamel epithelium. (05 Mar 2000) |
| vegetative stage | The quiescent stage of a cell or its nucleus in which no karyokinetic changes are taking place. Synonym: vegetative stage. (05 Mar 2000) |
| genital stage | Referring to the psychic organization derived from, and characteristic of, the Freudian genital period of the infant's psychosocial organization. See: genitality. See: anality, orality. (05 Mar 2000) |
| mechanical stage | <microscopy> A device provided for adjusting the position of a specimen, usually by translation in two directions at right angles to each other. (05 Aug 1998) |
| REM stage sleep | <physiology> A stage of deep sleep that is accompanied by rapid eye movement and muscle paralysis. Vivid dreams can be recalled in over 80% of patients who awake from REM stage sleep. (27 Sep 1997) |