The spinal cord is a direct continuation of the brain located within the vertebral canal. We can divide the spinal cord into four different regions: cervical (C), thoracic (T), lumbar (L), and sacral (S). These spinal segments are connected to different parts of your body through 31 pairs of spinal nerves. The spinal nerves emerge between each vertebra.
As the spinal cord doesn’t fill out the vertebral column completely, it ends between the first and second lumbar vertebrae. The collection of nerves that emerge from there consists of lumbar and sacral nerves and the coccygeal nerve, called the cauda equina, as it resembles a horse's tail.
The spinal cord’s primary functions are transmitting various stimuli from the environment and the inside of the body to the brain and sending brain “commands” to the periphery. It is also capable of autonomous activities such as coordinating reflexes and immediate responses to certain stimuli.
Figure 1: Spinal cord and dermatomes