Spinal Cord Health Article

Role in human health

The spinal cord is an extremely important component of the CNS because it provides the crucial link between the brain and the spinal nerves that connect to the individual muscles and organs of the body. The role of the spinal cord in human health however, is not only to carry this sensory and motor information. It also carries a great deal of other crucial information as well, having to do with involuntary and automatic body functions. For example, the regulation of the chemical contents of the blood and body fluids is carried out by an automatic feedback control system that involves the spinal cord and its attached network of peripheral nerves. The regulation the heart, stomach, and intestines are other examples. These are all vital body functions of which we are unaware of and that all proceed with the involvement of the spinal cord nervous tissues.

KEY TERMS

Arachnoid mater—One of three meninges covering the central nervous system (CNS) the others are the dura and pia maters. The dura mater encloses the arachnoid which in turn covers the pia mater.

Brain stem—Lowest part of the brain that connects with the spinal cord. It is a complicated neural center with several neuronal pathways between the cerebrum, spinal cord, cerebellum, and motor and sensory functions of the head and neck. It consists of the medulla oblongata, the part responsible for cardiac and respiratory control, the midbrain, which is involved in basic, involuntary body functions, and the pons, where some cranial nerves originate.

Central nervous system (CNS)—One of two major divisions of the nervous system. The CNS consists of the brain, the cranial nerves and the spinal cord.

Cerebrospinal fluid (CSF)—A clear colorless fluid that circulates in the brain and in the subarachnoid spaces surrounding the brain and spinal cord. The CSF lies between the spinal cord and the arachnoid mater thereby suspending the spinal cord in fluid.

Cervical vertebrae—Vertebrae of the neck.

Epidural space—This space lies between the dura mater and the walls of the vertebral canal, it contains loose connective tissue, blood vessels and some fatty tissue.

Foramen—A hole in a bone usually for the passage of blood vessels and/or nerves.

Foramen magnum—Large opening at the base of the skull that allows passage of the spinal cord.

Intervertebral disk—Disk-shaped pads of fibrous cartilage interposed between the vertebrae of the vertebral column that provide cushioning and join the vertebrae together.

Meninges—The membranes that surround and protect the brain and spinal cord. There are three layers: the dura mater (outermost), arachnoid membrane (middle) and the pia mater (innermost).

Nervous system—The entire system of nerve tissue in the body. It includes the brain, the brainstem, the spinal cord, the nerves and the ganglia and is divided into the peripheral nervous system (PNS) and the central nervous system (CNS).

Paraplegia—Paraplegia is permanent paralysis of the trunk and lower limbs. It is caused by injury or disease affecting the spinal cord below the chest or waist.

Peripheral nerves—The nerves outside of the brain and spinal cord, including the autonomic, cranial, and spinal nerves. These nerves contain cells other than neurons and connective tissue as well as axons.

Peripheral nervous system (PNS)—One of the two major divisions of the nervous system. The PNS consists of the somatic nervous system (SNS), that controls voluntary activities and of the autonomic nervous system (ANS), that controls regulatory activities. The ANS is further divided into sympathetic and parasympathetic systems.

Quadraplegia—Quadraplegia is permanent paralysis of the trunk, lower and upper limbs. It is caused by injury or disease affecting the spinal cord at the neck level.

Sacrum—The triangular-shaped bone found between the fifth lumbar vertebra and the coccyx. It consists of five fused vertebrae and it articulates on each side with the bones of the pelvis (ilium), forming the sacroiliac joints.

Sensory nerve—A nerve that receives input from sensory cells, such as the skin or muscle receptors.

Skull—All of the bones of the head.

Spinal cord—Elongated part of the central nervous system (CNS) that lies in the vertebral canal of the spine and from which the spinal nerves emerge.

Vertebra—Flat bones that make up the vertebral column. The spine has 33 vertebrae.

Vertebral canal—Hollow part of the vertebral column formed by the vertebral foramina of the stacked vertebrae. It encloses the spinal cord.

Vertebral foramen—The opening formed in vertebrae that allows passage of the spinal cord.