Anatomic Overview of Spine Vertebral Column

Vertebral Column Located in the midsagittal plane of the posterior cavity Extends from the skull to the pelvis 2

Vertebral Column There are 33 bones in the adult vertebral column 7 Cervical 12 Thoracic 5 Lumbar 5 Sacral 4 Coccygeal

Vertebral Column At the inferior aspect of the column The sacrum Sacrum has 5 fused bones Coccyx is composed of 4 fused bones The sacrum Supports the rest of the vertebral column Provides the support necessary for the human body’s erectness The vertebrae Are separated by radiolucent fibrocartilage intravertebral disks 4

Vertebral Column Flexibility The column Limited motion between any two neighboring vertebrae Vertebral column (in total) is capable of substantial motion, because it is very flexible The column Also protects the spinal cord Provides points of attachment for the skull, thorax, and extremities 5

Vertebral Characteristics Most vertebrae share several common characteristics: They have a body that is attached to a posterior vertebral arch. These two components border the vertebral foramen, the passage through which the spinal cord passes. 6

Vertebral Characteristics

Vertebral Characteristics There are spinous and transverse processes that allow for muscle attachments. The spinous process is posterior and forms where two laminae meet. The transverse processes are lateral projections where a pedicle joins a lamina. 8

Vertebral Characteristics The first two vertebrae, C1 and C2, are atypical from all others: C1, the atlas: Serves the specialized function of supporting the skull Allows the skull to turn The atlas has NO body C2, the axis: Has the dens or odontoid process that extends into the ring of the atlas When the head turns from side to side, it pivots on this process 9

Vertebral Characteristics

Vertebral Curvature The vertebral column has several curvatures that develop at different levels, which can be classified as either primary or secondary (compensatory) curvatures. Primary curvature develops in utero as the fetus develops in the C-shaped fetal position and is present at birth. Secondary curvature develops after birth as the child learns to sit up and walk. 11

Vertebral Curvature Cervical Curve The cervical curve Extends from the first cervical to the second thoracic vertebrae Is convex anteriorly Develops as the child learns to hold his or her head up and sits alone Approximately 4 months of age This is a secondary curvature. (From Support and Movement. In Thibodeau GA, Patton KT, editors: Anatomy and physiology, ed 2, St Louis, 1993, Mosby.) 12

Vertebral Curvature Lumbar Curve The lumbar curve Runs from T12 to the anterior surface of L5 Is a convex forward curve Develops when the child learns to walk Approximately 1 year of age This is a secondary curvature. (From Support and Movement. In Thibodeau GA, Patton KT, editors: Anatomy and physiology, ed 2, St Louis, 1993, Mosby.) 13

Vertebral Curvature Thoracic Curve The thoracic curve Extends from T2 to T12 Is concave anteriorly This is a primary curvature. (From Support and Movement. In Thibodeau GA, Patton KT, editors: Anatomy and physiology, ed 2, St Louis, 1993, Mosby.) 14

Vertebral Curvature Pelvic Curve The pelvic curve Is concave anteriorly and inferiorly Extends from the anterior surfaces of the sacrum and coccyx This is a primary curvature. (From Support and Movement. In Thibodeau GA, Patton KT, editors: Anatomy and physiology, ed 2, St Louis, 1993, Mosby.) 15

Vertebral Curvature Abnormal Curvatures Three abnormal curvatures are also present both clinically and radiographically: Kyphosis Scoliosis Lordosis 16

Vertebral Curvature Kyphosis Kyphosis (Greek: kyphos, a hump) also called hunchback, hunchbackism, or hunchbackedness Is an excessive curvature of the vertebral column that is convex posteriorly In general terms, is a common condition of a curvature of the upper (thoracic) spine Can be either the result of bad posture (slouching) or a structural, muscular abnormality in the spine 17

Vertebral Curvature Scoliosis An abnormal lateral curve of the vertebral column Excessive right or left curvature in the thoracic region Can develop if only one side of the vertebral bodies are irradiated in pediatric patients 18

Vertebral Curvature Lordosis Lordosis (commonly referred to as swayback, saddle back, or hyperlordosis) Is an excessive convexity of the lumbar curve of the spine Medical term used to describe an inward curvature of a portion of the vertebral column 19