Human back facts for kids

The human back is the large posterior area of the human body, rising from the top of the buttocks to the back of the neck and the shoulders. It is the surface of the body opposite from the chest. The vertebral column runs the length of the back and creates a central area of recession. The breadth of the back is created by the shoulders at the top and the pelvis at the bottom.

Back pain is a common medical condition, generally benign in origin.

Structure

The central feature of the human back is the vertebral column, specifically the length from the top of the thoracic vertebrae to the bottom of the lumbar vertebrae, which houses the spinal cord in its spinal canal, and which generally has some curvature that gives shape to the back. The ribcage extends from the spine at the top of the back (with the top of the ribcage corresponding to the T1 vertebra), more than halfway down the length of the back, leaving an area with less protection between the bottom of the ribcage and the hips. The width of the back at the top is defined by the scapula, the broad, flat bones of the shoulders.

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  View of the bones of the thorax and shoulders from behind.

Muscles

The spine is bordered by several groups of muscles, including the intertransversarii muscles, which facilitate movement between the individual vertebrae, and the multifidus spinae, which facilitate the movement of the spine as a whole.

Other muscles in the back are associated with the movement of the neck and shoulders. The trapezius muscle, which is named from its trapezium-like shape, runs between the neck, the anterior chain, the two shoulders, and the thoracic vertebra, T12. The large latissimus dorsi make a triangle from the shoulder to the hip.

Organs of the back

The lungs are within the ribcage, and extend to the back of the ribcage making it possible for them to be listened into through the back. The kidneys are situated beneath the muscles in the area below the end of the ribcage, loosely connected to the peritoneum. A strike to the lower back can damage the kidneys of the person being hit.

Surface of the back

The skin of the human back is thicker and has fewer nerve endings than the skin on any other part of the torso. With some notable exceptions, it tends to have less hair than the chest on men. The upper-middle back is also the one area of the body which a typical human under normal conditions might be unable to physically touch.

The skin of the back is innervated by the dorsal cutaneous branches, as well as the lateral abdominal cutaneous branches of intercostal nerves.

Movement

The intricate anatomy of the back provides support for the head and trunk of the body, strength in the trunk of the body, as well as a great deal of flexibility and movement. The upper back has the most structural support, with the ribs attached firmly to each level of the thoracic spine and very limited movement. The lower back (lumbar vertebrae) allows for flexibility and movement in back bending (extension) and forward bending (flexion). It does not permit twisting.

Clinical significance

Back pain

The back comprises interconnecting nerves, bones, muscles, ligaments, and tendons, all of which can be a source of pain. Back pain is the second most common type of pain in adults (the most common being headaches). By far the most common cause of back pain is muscle strain. The back muscles can usually heal themselves within a couple of weeks, but the pain can be intense and debilitating. Other common sources of back pain include disc problems, such as degenerative disc disease or a lumbar disc herniation, many types of fractures, such as spondylolisthesis or an osteoporotic fracture, or osteoarthritis.

Images for kids

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  Posterior view of muscles connecting the upper extremity to the vertebral column. A Trapezius B Teres Major C Teres Minor D Latissimus Dorsi E Levator Scapulae F Rhomboid Major

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  Distribution of cutaneous nerves, dorsal aspect. Dorsal and lateral cutaneous branches labeled at center right.

See also

In Spanish: Espalda para niños