Let s learn about the spinal cord. The spinal cord begins at the foramen magnum and ends at the second lumbar vertebra or L2. The spinal cord ends in a cone shaped process called the conus medularis. Here is another picture of the conus medularis. Extending from the inferior portion of the spinal cord is a group of nerves called the cauda equine which means horses tail. The inferior portion of the spinal cord is anchored by a ligament called the filum terminale. The spinal cord contains some bulges or enlargments in the cervical and lumbar areas. There are 31 pair of spinal nerves that emerge from the spinal cord. Here is a transverse section of the spinal cord. The spinal cord is covered by the meninges. There are 3 layers to the meninges. The outer layer is a tough fibrous layer called the dura mater. Inside of the dura mater is the arachnoid mater. The pia mater contacts the surface of the spinal cord. There is a space between the arachnoid and pia mater called the subarachnoid space which is filled with cerebrospinal fluid. The basic structure of the spinal cord is an outer portion of white matter and an inner portion of gray matter. 2 nerve roots exit the spinal cord and combine to form a spinal nerve. The nerve roots are called the dorsal and ventral roots. The dorsal root contains the dorsal root ganglion which is a collection of cell bodies. The white matter is divided into areas called funiculi. Here is the posterior funiculus. Here is the lateral funiculus. Here is the anterior funiculus. The gray matter is divided into horns. There is a posterior horn, lateral horn and anterior horn. Other structures include grooves called the posterior median sulcus and ..anterior median fissure. The gray commissure is a gray matter bridge that unites both right and left sides of the spinal cord. The central canal contains cerebrospinal fluid. The white matter contains spinal tracts which are pathways for nervous system impulses. The ascending or sensory tracts carry information to the brain. The descending tracts carry information from the brain which ends up at effectors which are muscles, organs or glands. Most of the tracts cross to the other side of the spinal cord or brain. Here are a few of the tracts. The fasciculus gracilis and cuneatus carry information for discriminitive touch, vibration, pain, proprioception. The Lateral spinothalamic tract carries pain and temperature information. The Anterior spinothalamic tract carries information for light touch and pain. The Spinocerebellar tracts (anterior and posterior) carry coordination information. The Corticospinal tracts carry motor information to skeletal muscles. The Rubrospinal tract carries motor information to skeletal muscles and the Reticulospinal tract carries motor information to skeletal muscles and sweat glands. We hope you have learned something about spinal cord anatomy and see you next time.