Anaesthesia Practice
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ANAESTHESIA PRACTICE
Issue 22
SPINAL ANAESTHESIA
SPINAL CORD ANATOMY VERTEBRAE Vertebral column is central bony pillar of the body. It is composed of 33 vertebrae; 7 cervical, 12 thoracic, 5 lumbar, 5 sacral and 4 coccygeal. Sacral hiatus is th th formed because of incomplete 5 and sometime 4 sacral laminae. A typical vertebra consists of a rounded body anteriorly and a vertebral arch posteriorly (arch consists of two pedicles and two laminae). The vertebral arch encloses the vertebral canal through which the spinal cord is running. Seven processes arise from the arch: one spinous, two transverse and four articular. The gap between two pedicles forms the intervertebral foramen which transmits the spinal nerves and blood vessels(Fig). LIGAMENTS Anterior and posterior longitudinal ligament: Both these ligaments start from the skull to sacrum and are attached on the anterior and posterior surface of the vertebral bodies and intervertebral disks. Ligamentum flavum:It connects the laminae of two adjacent vertebrae and is pierced during spinal anesthesia or lumber puncture. Interspinous & supraspinous ligament (ligament nuchae):It connects the supraspinous and intraspinous processes. SPINAL CORD Spinal cord is an elongated, cylindrical and greyish white structure of central nervous system. It hangs in the vertebral canal, surrounded by meninges and cerebrospinal fluid. It is continuous above with medulla oblongata and terminates inferiorly in adults at lower border of first lumber vertebra. In children; it ends at upper border of third lumber vertebra. Its length is approximately 45 cm in adults. Blood supply is from anterior spinal artery, two posterior spinal arteries and from the branches of cervical, intercostal and lumber arteries. The artery of Adamkiewicz arises from the left side at lower thoracic or upper lumber level and supplies the lower two thirds of spinal cord. There are thirty one pairs of spinal nerves (8 cervical, 12 thoracic,
ANAESTHESIA PRACTICE
Issue 22
SPINAL ANAESTHESIA
SPINAL CORD ANATOMY VERTEBRAE Vertebral column is central bony pillar of the body. It is composed of 33 vertebrae; 7 cervical, 12 thoracic, 5 lumbar, 5 sacral and 4 coccygeal. Sacral hiatus is th th formed because of incomplete 5 and sometime 4 sacral laminae. A typical vertebra consists of a rounded body anteriorly and a vertebral arch posteriorly (arch consists of two pedicles and two laminae). The vertebral arch encloses the vertebral canal through which the spinal cord is running. Seven processes arise from the arch: one spinous, two transverse and four articular. The gap between two pedicles forms the intervertebral foramen which transmits the spinal nerves and blood vessels(Fig). LIGAMENTS Anterior and posterior longitudinal ligament: Both these ligaments start from the skull to sacrum and are attached on the anterior and posterior surface of the vertebral bodies and intervertebral disks. Ligamentum flavum:It connects the laminae of two adjacent vertebrae and is pierced during spinal anesthesia or lumber puncture. Interspinous & supraspinous ligament (ligament nuchae):It connects the supraspinous and intraspinous processes. SPINAL CORD Spinal cord is an elongated, cylindrical and greyish white structure of central nervous system. It hangs in the vertebral canal, surrounded by meninges and cerebrospinal fluid. It is continuous above with medulla oblongata and terminates inferiorly in adults at lower border of first lumber vertebra. In children; it ends at upper border of third lumber vertebra. Its length is approximately 45 cm in adults. Blood supply is from anterior spinal artery, two posterior spinal arteries and from the branches of cervical, intercostal and lumber arteries. The artery of Adamkiewicz arises from the left side at lower thoracic or upper lumber level and supplies the lower two thirds of spinal cord. There are thirty one pairs of spinal nerves (8 cervical, 12 thoracic,