From Big Medical Encyclopedia

BACK [dorsum (PNA, JNA, BNA)] — the tail of a trunk located between a neck and a rump.

The anatomy

S.'s Surface is limited to the conditional line passing from above through an acantha of the VII cervical vertebra, acromial and clavicular joints and further on the rear edge of deltoid muscles; from below S.'s border passes on ileal crests of haunch bones and side edges of a sacrum to a tailbone; lateralno — on back axillary lines. By means of the back midline corresponding to tops of acanthas of vertebrae, S. is divided into two more or less symmetric half. Allocate the following areas for S.'s surfaces: back upper area of a breast, or scapular area (regio thoracis post, sup., s. regio scapularis), back lower area of a breast, or infrascapular area (regio thoracis post, inf., s. regio infrascapularis), lumbar area (regio lumbalis), to-rye are steam rooms; unpaired area — back median area of a breast, or vertebral area (regio mediana thoracis post., s. regio vertebralis). Scapular and infrascapular areas make a back chest wall (see. Thorax , Breast , Scapular area ); lumbar area (see); is a part of a back wall of an abdominal cavity; vertebral area and sacral area (see) match according to projections to the surface of the Village. backbone (see) and sacrum.

S.'s skin dense, is thicker, than on a front surface of a trunk. Hypodermic cellulose is well-marked. A superficial fascia, covering S.'s muscles, passes to the neighboring areas. Own fascia of S. includes several fastion. The thoracolumbar fascia (fascia thoracolumbalis) consisting of two plates is most developed: superficial and deep. The superficial plate is fixed on ileal crests of haunch bones and acanthas of vertebrae, the broadest muscle of a back originates from it. The superficial plate creates a vagina for this muscle, and also for trapezoid, rhomboid, back top and bottom gear muscles. The deep plate begins from cross shoots of vertebrae, is attached to the XII edge and an ileal crest of a haunch bone. Both plates, connecting together, on each side from a backbone form bone and fascial space for the muscle straightening a backbone. From a deep plate the cross muscle of a stomach (m. transversus abdominis) begins. And low-extensible are thick supraspinal and podostny a fascia (fasciae supraspinata et infraspinata), to-rye are attached to a scapular awn and edges of a shovel. In a shovel at the expense of the fascial leaves and muscles surrounding it the closed spaces and cracks are formed (see. Scapular area ).

S.'s muscles divide on superficial, (trunkopetal-ny), and deep, developed from dorsal departments of myotomes (autokhtonny) moved from the head and an upper extremity. Superficial and deep muscles of S. (see article Muscles , fig., p. 65, 66, 67 and tsvetn. fig. 2) are separated from each other by a thoracolumbar fascia. Carry to superficial muscles of S.: trapezoid (m. trapezius) — partially; the broadest muscle of a back (m. latissimus dorsi); big and small rhomboid muscles (mm. rhomboidei major et minor); the muscle raising a shovel (m. levator scapulae) — partially; top and bottom back gear muscles (mm. serrati posteriores sup. et inf.); square muscle of a waist (m. quadratus lumborum). Muscles of a backbone belong to deep: the muscle straightening a backbone (m. erector spinae); cross and awned (m. trans-versospinalis), interspinal muscles (mm. interspinales), intercross muscles (mm. intertransversarii), an also intercostal muscles (see. Muscles, list of names of muscles ).

S.'s blood supply is carried out by back branches back intercostal and dorsal branches of lumbar arteries, outflow of blood happens in the veins of the same name.

Limf, S.'s vessels follow to lumbar (nodi lymphatici lumbales), intercostal (nodi lymphatici intercostales) and axillary (nodi lymphatici axillares) limf, to nodes.

The innervation of skin and deep muscles of S. is carried out by back branches of chest and lumbar spinal nerves, superficial muscles — intercostal nerves and short branches of a brachial plexus. Trapezoid muscles are innervated by back branches of spinal nerves and eleventh cranial nerves.

Pathology — see articles devoted to certain areas of a back (e.g., Scapular area, the Backbone, Lumbar area, etc.).

Bibliography: Kirpatovsky I. D. and V. Ya. Coopers. Relief anthropotomy, M., 1974; Surgical anatomy of a breast, under р^д. A. N. Maksimenko-va, D., 1955; Surgical anatomy of a stomach, under the editorship of A. N. Maksimenkov, L., 1972.

S. S. Mikhaylov.