Beginning of spinal cord:
Spinal cord begins at the foramen magnum as a continuation of the medulla Oblongata of the brain.
Shape of spinal cord: It is Cylindrical.
Length of spinal cord: Is about (45) cm.
It occupies upper 2/3 of the vertebral (spinal) canal of the vertebral column.
Levels of termination in different age groups
(1) Up till the 3rd month of fetal life: The spinal cord occupies the entire length of the vertebral canal.
(2) At birth : It terminates at the level of L3.
(3) Children : It ends at the Upper Border of the 3rd Lumbar vertebra.
(4) Adults : It terminates at the intervertebral disc (1st-2nd ) lumbar vertebrae.
Enlargement of spinal cord
Cervical : (C3- T1) Segments for the Brachial Plexus.
Lumbar : (L1- S3) Segments, for the Lumbar and Sacral Plexuses.
Mode of termination of spinal cord
Conus Medullaris : A conical termination caudal to the lumbar enlargement.
Filum terminale : A filament of connective tissue arises from the tip of the conus. It is attached to the 1st Coccygeal vertebra.
