{"id":20341,"date":"2022-06-28T01:05:34","date_gmt":"2022-06-28T01:05:34","guid":{"rendered":"https:\/\/www.knowlative.com\/?p=20341"},"modified":"2022-06-28T01:05:34","modified_gmt":"2022-06-28T01:05:34","slug":"the-vertebral-column","status":"publish","type":"post","link":"https:\/\/www.knowlative.com\/it\/the-vertebral-column\/","title":{"rendered":"The Vertebral Column"},"content":{"rendered":"
<\/p>\n
The vertebral column is also known as the spinal column or spine. It consists of a sequence of vertebrae (singular = vertebra), each of which is separated and united by an intervertebral disc. Together, the vertebrae and intervertebral discs form the vertebral column. It is a flexible column that supports the head, neck, and body and allows for their movements. It also protects the spinal cord, which passes down the back through openings in the vertebrae. The vertebral column originally develops as a series of 33 vertebrae, but this number is eventually reduced to 24 vertebrae, plus the sacrum and coccyx. An interesting anatomical fact is that almost all mammals have seven cervical vertebrae, regardless of body size. This means that there are large variations in the size of cervical vertebrae, ranging from the very small cervical vertebrae of a shrew to the greatly elongated vertebrae in the neck of a giraffe. In a full-grown giraffe, each cervical vertebra is 11 inches tall. The adult vertebral column does not form a straight line, but instead has four curvatures along its length. These curves increase the vertebral column\u2019s strength, flexibility, and ability to absorb shock. When the load on the spine is increased, by carrying a heavy backpack for example, the curvatures increase in depth (become more curved) to accommodate the extra weight. They then spring back when the weight is removed. <\/p>\n
\n \u00a0<\/strong> <\/p>\nRegions of the Vertebral Column<\/strong><\/h5>\n
\n The vertebral column is subdivided into five regions, with the vertebrae in each area named for that region and numbered in descending order: <\/p>\n\n
\n \u00a0 <\/p>\nCurvatures of the Vertebral Column<\/strong><\/h5>\n
\n The four adult curvatures are classified as either primary or secondary curvatures. Primary curves are retained from the original fetal curvature, while secondary curvatures develop after birth.
\n During fetal development, the body is flexed anteriorly into the fetal position, giving the entire vertebral column a single curvature that is concave anteriorly. In the adult, this fetal curvature is retained in two regions of the vertebral column as the thoracic curve<\/strong>, which involves the thoracic vertebrae, and the sacrococcygeal curve<\/strong>, formed by the sacrum and coccyx. Each of these is thus called a primary curve<\/strong> because they are retained from the original fetal curvature of the vertebral column.
\n A secondary curve<\/strong> develops gradually after birth as the child learns to sit upright, stand, and walk. Secondary curves are concave posteriorly, opposite in direction to the original fetal curvature. The cervical curve<\/strong> of the neck region develops as the infant begins to hold their head upright when sitting. Later, as the child begins to stand and then to walk, the lumbar curve<\/strong> of the lower back develops. In adults, the lumbar curve is generally deeper in females.
\nDisorders associated with the curvature of the spine include kyphosis (an excessive posterior curvature of the thoracic region), lordosis (an excessive anterior curvature of the lumbar region), and scoliosis (an abnormal, lateral curvature, accompanied by twisting of the vertebral column). \u00a0 \u00a0\u00a0 <\/p>\n