About the diameter of a human finger, the spinal cord is connected to the brain and is an important part of the human anatomy. The vertebral column protects the spinal cord as it descends along the middle of the back. The Cerebral Spinal Fluid is responsible for protecting the nerve fibres from damage due to friction or impact with the vertebrae. The spinal cord itself, along with the brain forms the central nervous system of the body. These are the parts which a spinal cord diagram will indicate to you.
Regions and Spinal Nerves
A spinal cord diagram will show you 4 distinct regions. These are the cervical region, thoracic region, the lumbar region and the sacral region from top to bottom. The cervical region is connected to the eye, lachrymal glands, sweat glands, hair follicles, blood vessels of arms, head and neck and salivary glands. The cervical nerves are also connected to biceps, deltoids, wrist extenders, hand and triceps. The thoracic region is connected to heart, lungs, stomach, duodenum, pancreas, liver and kidney. The thoracic nerves are also connected to chest muscles and abdominal muscles. The lumbar region is connected to rectum, bladder, colon and external genitalia. The lumbar nerves are connected to the leg muscles. The sacral region is connected to blood vessels of lower limbs and perineum, hair follicles and sweat glands.
Numbering System
Another thing you will observe on a spinal cord diagram is the spinal cord level numbering system which is similar to that of the vertebrae. The spinal cord ends at the conus medullaris near the lumbar nerves referred to as L1 and L2. All in all there are 31 spinal nerve pairs which branch off to various parts of the body. Spinal nerves leaving from the spinal cord are numbered based on the vertebra at which they exit the spinal column.
A spinal cord diagram will therefore show nerves C1 – C8 which are related to the upper aspects of vertebral organisms. Similarly there is T1 – T12, where T4 spinal nerve is on level with the nipple line while T6 is level with the sternum bottom. T10 is level with the abdomen while T12 is level with pubic bone. Then there are lumbar nerves L1 – L5 whose sensation is over the legs. The Sacral nerves are numbers S1 – S5. The perineal genital area sensation is related to S3, S4 and the S5 nerves.
For more information and explanations on the spinal cord diagram, you can visit http://www.spinalcorddiagram.net/