| straight back syndrome | <syndrome> Loss of the normal concavity of the thoracolumbar spine with a narrowed anteroposterior chest dimension, resulting compression of the heart between spine and sternum, and consequent prominent precordial pulsations, an ejection murmur, and radiologic evidence of a widened cardiac silhouette (pancaked heart). (05 Mar 2000) |
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| superficial back muscles | Muscles originating from the vertebral column and having their fleshy bellies located in the back, but inserting onto the appendicular skeleton of the upper limb or the ribs. They are not innervated by dorsal primary rami of spinal nerves, as are the deep or true muscles of the back; includes the trapezius muscle (innervated by spinal accessory nerve) and latissimus dorsi, rhomboids, levator scapulae, and thoracic muscles (innervated by ventral primary rami of spinal nerves, or derivatives thereof). (05 Mar 2000) |
| deep muscles of back | Muscles of the back innervated by the dorsal primary rami of spinal nerves; includes erector spinae, transversospinalis, interspinal, and intertransverse muscles; excludes the superficial back muscles which are appendicular and are innervated by ventral rami, and the trapezius, innervated by the spinal accessory nerve. Synonym: true muscles of back. (05 Mar 2000) |
| diamond-back | <zoology> The salt-marsh terrapin of the Atlantic coast (Malacoclemmys palustris). Source: Websters Dictionary (01 Mar 1998) |
| double back cross | A mating that is a back cross at each of two loci of interest; of special value and importance in linkage analysis. (05 Mar 2000) |
| topping and back pressure turbine | Turbines which operate at exhaust pressure considerably higher than atmospheric (noncondensing turbines). These turbines are often multistage types with relatively high efficiency. (05 Dec 1998) |
| true muscles of back | Muscles of the back innervated by the dorsal primary rami of spinal nerves; includes erector spinae, transversospinalis, interspinal, and intertransverse muscles; excludes the superficial back muscles which are appendicular and are innervated by ventral rami, and the trapezius, innervated by the spinal accessory nerve. Synonym: true muscles of back. (05 Mar 2000) |
| fold-back elements | A type of transposable element that possesses long inverted repeats, such that when denatured, loops are formed. (05 Mar 2000) |
| low back pain | A continuous pain in the lower back or lumbar region. (12 Dec 1998) |