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The spinal cord is a very important part of the human body. It is responsible for a variety of functions, including the transmission of messages between the brain and the muscles, the regulation of autonomic functions such as heart rate and respiration, and the facilitation of movement. Any injury to the spinal cord can have a very detrimental effect on the overall wellbeing of an individual.
It is an unfortunate truth many that we often take our health for granted, or even ignore it altogether, assuming that it will take care of itself without requiring any conscious effort from us. Everything will proceed normally for some time, but then some part of the body protests angrily and exacts vengeance on the overall wellbeing of the body. It is during those times that we begin to realize that we should have taken better care of ourselves.
A very important, yet commonly neglected (especially by youngsters), part of every human body is the spinal cord. Given its importance, let’s take a closer look at what makes the spinal cord so special and why it requires proper care.
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Spinal Cord
The Spinal Cord is the thin, tubular bundle of nervous tissue and support cells that runs from the head to the lumbar region of the vertebral column. Simply put, it is the one long bone that you can feel at the center of your back. The human brain and spinal cord together comprise a system that is crucial for the survival of human beings; the Central Nervous System (CNS).
In men, the average length of the spinal cord is around 18 inches (45 centimeters), and in women, it averages 17 inches (43 centimeters). The average thickness of the spinal cord also varies in different areas; it is as thick as half an inch (13 millimeters) in the cervical region (near the neck) to roughly half that thickness, 6.4 millimeters, in the thoracic area (mid portion of the spine).
Also Read: What Are The Different Types Of Vertebrae?
Anatomy Of The Spinal Cord
The spinal cord is divided into four major parts: the cervical, thoracic, lumbar, and sacral nerves. Collectively, the entire spinal cord is divided into 31 segments; at every segment, there is a pair of right and left spinal nerves. From each of these, 6 to 8 nerve rootlets branch out in a definite and regular pattern.
Cross-section Of The Spinal Cord
When we observe the cross-section, we see the cord divided into grey matter and white matter. The grey matter is butterfly shaped and surrounded by white matter. Sensory information is constantly sent to the brain while the motor information is sent to the muscles. So we need some place from where the nerves can enter and exit the spinal cord, right? This job is done by the posterolateral sulcus, from where dorsal roots enter and send sensory information to the brain. While the anterolateral sulcus helps the ventral roots to exit and carry motor information to the muscles.
The grey matter is divided into three regions:
- Posterior horn – Contains interneurons that make connections with spinal cord and neurons that carry sensory information the brain. A specific section called the substantia gelatinosa contains neurons that carry temperature and pain signals to the brain
- Anterior horn – Contains motor neurons that signal skeletal muscles. They are called alpha motor neurons. They leave via the ventral roots.
- Intermediate grey matter – Contains neurons involved in autonomic functions such as heart rate and respiration.
The white matter consists of ascending (carrying sensory information to the brain) and descending (carrying motor information to the body) fibers. These fibers are called funiculi. There are three different funiculi.
- Posterior funiculi – It is located at the back of the spinal cord. It contains pathways that inform the brain about touch and limb position.
- Lateral funiculi – It is at the (yes you guessed it) at the lateral portion of the cord. It has pain pathways and also descending pathways responsible for causing movements.
- Anterior funiculi – It has multiple ascending and descending pathways.
Also Read: What Are Cranial Nerves?
Functions
Since it is a component of the Central Nervous System, it goes without saying that the spinal cord plays a critical role in the overall wellbeing of a human body. The spinal cord consists of many neural pathways that facilitate the passage of message at inconceivably fast speeds.
An impulse originates in the brain and travels through an extensive network of neurons, which are linked by synapses, in order to reach its intended destination. For instance, when you get pricked by a needle, the brain instantly sends an impulse that travels through the spinal cord to tell the muscles in the hand to pull away, causing you to (almost) instantly pull your hand away.
The spinal cord is the facilitator in a host of functions that you need to perform at almost every moment of your life; whether you are sitting, eating, walking, jogging or doing anything else that involves muscles and glands (pretty much everything), your spinal cord is watching your back – literally!
Since all the messages transmitting movement, temperature, touch, and vibration affecting the skin, joints, muscles, and internal organs are relayed through the spinal cord, any injury to the spinal cord can prove to be very detrimental for the health of an individual. Injuries to the spinal cord may cause paralysis, bowel movement disorders, the proper circulation of blood, sexual problems, and even depression.
In other words, it is imperative that you take good care of your back. On easy way to do this is to avoid sitting too long in one place; if your work involves sitting at a desk for long stretches of hours, make sure that you get up occasionally and perform some back exercises while sitting. Consider taking small walks throughout the day, which will allow your backbone to remain strong. The best advice, however, is to exercise regularly, as this helps in many ways, such as keeping the body in shape, reducing pressure on the backbone, regulating blood circulation, and keeping your body strong and flexible.
Also Read: Why Are Reflex Actions Faster Than Typical Movements?
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References (click to expand)
- Spinal cord - Wikipedia. Wikipedia
- What does the spinal cord do? - UAB. The University of Alabama at Birmingham
- Anatomy of the Spinal Cord (Section 2, Chapter 3) Neuroscience Online: An Electronic Textbook for the Neurosciences | Department of Neurobiology and Anatomy - The University of Texas Medical School at Houston - neuroscience.uth.tmc.edu:80
