| brachiocephalic trunk | The first and largest artery branching from the aortic arch. It distributes blood to the right side of the head and neck and to the right arm. (12 Dec 1998) |
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| brachiocephalic veins | Large veins on either side of the root of the neck formed by the junction of the internal jugular and subclavian veins. They drain blood from the head, neck, and upper extremities, and unite to form the superior vena cava. (12 Dec 1998) |
| brachiocrural | Relating to both arm and thigh. (05 Mar 2000) |
| brachiocubital | Relating to both arm and elbow or to both arm and forearm. (05 Mar 2000) |
| brachioganoidei | <zoology> An order of ganoid fishes of which the bichir of Africa is a living example. See Crossopterygii. Origin: NL, from L. Brachium (bracch-) arm + NL. Ganoidei. Source: Websters Dictionary (01 Mar 1998) |
| brachiogram | Tracing of the brachial artery pulse. (05 Mar 2000) |
| brachiopod | A phylum of invertebrate animals often grouped with two other phyla under the name Lophophorates. General characteristics include: a pair of protective shells (giving them a superficial resemblance to the bivalves - i.e. Clams), a stalk protruding from the rear called a pedicle which anchors the animal to the sea floor, and a lophophore (a ridge with many tiny tentacles on it, used to catch food particles floating by). Brachiopod shells come in many different shapes and sizes. Brachiopods were extremely abundant during the Paleozoic era (both in terms of numbers of individuals and numbers of species), but were practically wiped out around 300 million years ago during the Permian mass extinction.Compare gastropod (09 Oct 1997) |
| brachiopoda | <zoology> A class of Molluscoidea having a symmetrical bivalve shell, often attached by a fleshy peduncle. Within the shell is a pair of "arms," often long and spirally coiled, bearing rows of ciliated tentacles by which a current of water is made to flow into the mantle cavity, bringing the microscopic food to the mouth between the bases of the arms. The shell is both opened and closed by special muscles. They form two orders; Lyopoma, in which the shell is thin, and without a distinct hinge, as in Lingula; and Arthropoma, in which the firm calcareous shell has a regular hinge, as in Rhynchonella. See Arthropomata. Origin: NL, from Gr. Arm + -poda. Source: Websters Dictionary (01 Mar 1998) |
| brachioradial muscle | <anatomy, muscle> Origin, lateral supracondylar ridge of humerus; insertion, front of base of styloid process of radius; action, flexes elbow and assists slightly in supination; nerve supply, (common) radial. Synonym: musculus brachioradialis, brachioradial muscle. (05 Mar 2000) |
| brachioradial reflex | With the arm supinated to 45 |
| brachioradialis | <anatomy, muscle> Origin, lateral supracondylar ridge of humerus; insertion, front of base of styloid process of radius; action, flexes elbow and assists slightly in supination; nerve supply, (common) radial. Synonym: musculus brachioradialis, brachioradial muscle. (05 Mar 2000) |
| brachium | Origin: L. Brachium or bracchium, arm. <anatomy> The upper arm; the segment of the fore limb between the shoulder and the elbow. Source: Websters Dictionary (01 Mar 1998) |
| brachium colliculi inferioris | A fibre bundle passing from the inferior colliculus on either side of the brainstem along the lateral border of the superior colliculus to the posterior part of the thalamus where it enters the medial geniculate body. It forms part of the major ascending auditory pathway. Synonym: brachium colliculi inferioris, brachium quadrigeminum inferius, inferior quadrigeminal brachium. (05 Mar 2000) |
| brachium colliculi superioris | A band of fibres of the optic tract bypassing the lateral geniculate body to terminate in the superior colliculus and pretectal region. Synonym: brachium colliculi superioris, brachium quadrigeminum superius, superior quadrigeminal brachium. (05 Mar 2000) |
| brachium conjunctivum cerebelli | A large bundle of nerve fibres that originate from the dentate and interpositus nuclei and emerges from the cerebellum in the rostral direction, along the lateral wall of the fourth ventricle. The bundle submerges from the dorsal surface of the brainstem into the mesencephalic tegmentum, where all of its fibres cross in the massive decussation of the superior cerebellar peduncles. Part of the bundle terminates in the contralateral red nucleus; the bulk of the fibres continue rostrally to parts of the ventral intermediate nucleus of thalamus, ventral posterolateral nucleus of thalamus, and central lateral nucleus of thalamus. Synonym: pedunculus cerebellaris superior, brachium conjunctivum cerebelli. (05 Mar 2000) |