THE HUMAN SPINE: THE HUB OF THE NERVOUS SYSTEM

What do you think of when you see the human spine? Bones? Skeleton? X-rays? Halloween? Now what if you ask a chiropractor that exact same question? In this week’s blog, we will talk about the purpose of the human spine, each section of the spine and how to keep the spine in good health.

The Human Spine

First, and foremost, we need to discuss the overall purpose of the spine. The spine has two overall functions. The first is assisting in movement. Muscles attach directly to bones which allow for flexion, extension, lateral and rotation motions. The second and most important function is that it’s a protective hardcase for the spinal cord and nervous system. It ensures the nervous system will not get damaged and the body can run at optimal levels. Remember, without the nervous system, we can’t do anything: walk, talk, see, smell, hear, taste, move, feel, breathe and most importantly, survive!

In order for the spinal cord to be fully protected, the spine consists of 33 different bony segments over 5 different regions that each play a role in protection and function. The five different regions of the spine include: cervical, thoracic, lumbar, sacral & coccygeal. Other than protecting the spinal cord, each region has its own functions and motion. 

The Cervical Spine

The cervical spine consists of the first seven cervical vertebrae (C1-C7). C1 and C2 are considered atypical vertebrae because they look different than the rest of the entire vertebral column. C1 is typically called atlas, and it assists in flexion/extension movements of the head. C2 is typically called axis, and it assists in rotation movements of the head. The cervical spine has a specific, natural C-shaped curve called a lordosis that helps maintain posture and absorbs shock when movement occurs.

The muscles of the cervical spine allow for all movements of the neck: flexion, extension, lateral flexion, and rotation. The cervical spine consists of eight spinal nerve roots that allow for muscle movement and sensation of the neck, shoulders, arms, elbows, forearms, wrists, and fingers. Whenever misalignment of a vertebra or disc injury occurs, pressure is applied to the associated nerve root causing pain, muscle weakness and/or sensation loss in the area controlled by that specific nerve root. 

Aside from protecting the spinal cord, supporting the weight of the head and movement of the head and neck, one other important function of the cervical spine is that it facilitates arterial blood flow to the brain using small openings from C1-C6 called transverse foramen.

The Thoracic Spine and Ribcage

The thoracic spine consists of the next 12 vertebrae (T1-T12). Unlike the cervical spine, most levels of the thoracic spine have limited forward/backward and side-bending movements but significantly more ability for axial rotation. These dynamics are essentially flipped near the bottom of the thoracic spine with increased ranges of motion for forward/backward and side-bending movements but a reduced ability for axial rotation. Muscles of course allow these motions to occur. The thoracic spine has a specific, natural curve called a kyphosis that helps individuals properly balance and stand upright. 

The thoracic spine consists of 12 spinal nerve roots that allow for muscle movement and sensation of the upper, mid, and low back, chest, and abdomen. These nerves also innervate essential organs such as the lungs, heart, liver, stomach, and gallbladder to assist with breathing, regulation of blood flow, enzyme breakdown, digestion, and bile production respectively. Just like the cervical spine, whenever misalignment of a vertebra or disc injury occurs, pressure is applied to the associated nerve root causing pain, muscle weakness, sensation loss and organ dysfunction in the area controlled by that specific nerve root.   

Aside from protecting spinal cord and thoracic spine movement, another huge function of the thoracic spine is that it anchors the ribcage. The rib cage, supported by the thoracic spine in the back, forms a bony structure to surround and protect vital organs, such as the heart and lungs.

The ribcage consists of 24 ribs (12 on the left and 12 on the right). The first 7 pair of ribs are called true ribs as they attached directly to the sternum. The 8th, 9th, and 10th rib pairs are called false ribs that attach indirectly to the sternum.  The last 2 pair of ribs are called floating ribs and they do not attach to the sternum at all. Along with protection of internal organs, the ribs are critical in breathing since their flexibility in their movement increases/decreases the size of the thoracic cavity, assisting the lungs in respiration. 

The medical term for the breastbone is the sternum. The sternum’s function is to assist in ribcage protection of internal organs in chest and abdominal cavities, along with the attachment point of most ribs and collarbone. 

The Lumbar Spine

The lumbar spine consists of the final 5 vertebrae (L1-L5). The muscles of the lumbar spine have all movements that the neck does: flexion, extension, lateral flexion, and rotation; however, flexion and extension are greatest at L4 and L5 vertebra levels. Like the cervical spine, the lumbar spine has a specific, natural C-shaped curve called a lordosis that helps maintain posture and absorbs shock when movement occurs.

The lumbar spine consists of 5 spinal nerve roots that allow for muscle movement and sensation of the low back, thighs, legs, feet, and toes. These nerves also innervate to essential organs such as small/large intestine, kidneys, bladder, and sex organs to assist with digestion, filtration, urination, and sexual function respectively. Have you caught on to the trend yet? Just like everywhere else in the spine, whenever misalignment of a vertebra or disc injury occurs, pressure is applied to the associated nerve root causing pain, muscle weakness, sensation loss and organ dysfunction in the area controlled by that specific nerve root.   

Aside from protecting spinal cord and cauda equina, and movements of the back and legs, another important function of the lumbar spine is supporting and stabilizing the upper body. The lumbar vertebrae are the largest compared to other spinal regions and are designed that way because this is the most weight-bearing area. In conjunction with the muscles and ligaments, these vertebrae help support the weight of the upper body, including the head and neck. 

The Sacrum & Coccyx

The sacrum is a large, flat triangular shaped bone nested between the hip bones and positioned below the last lumbar vertebra (L5) that consists of 5 fused bones. The coccyx (tailbone) consists of 3-5 small, fused bones located directly underneath the sacrum. Unlike the rest of the spine, the sacrum and coccyx have very limited movement in all directions. These two structures were designed for weight bearing purposes. The sacrum uses its weight bearing forces to assist the pelvic girdle when upright and walking occurs. Along with joints, ligaments and muscles, these structures help stabilize the spine and keep the sacrum in place. The coccyx also assists in weight bearing actions but is done so in sitting positions. The coccyx is also used as attachment points for tendons, muscles and ligaments.

The spinal cord ends at L1-L2 creating the cauda equina; a bundle of spinal nerves resembling the tail of a horse. There are 5 sacral nerves that allow for muscle movement and sensation to the pelvis, back of the legs, feet, and toes. These nerves also innervate to essential organs such as bladder, and sex organs to assist with urination/bowel and sexual function. Just like everywhere else in the spine, whenever misalignment of a vertebra or disc injury occurs, pressure is applied to the associated nerve root causing pain, muscle weakness, sensation loss and organ dysfunction in the area controlled by that specific nerve root. 

How to Keep the Spine in Good Health

Why do we keep stressing that misaligned vertebra or disc injury can be the cause of pain and neurological deficits? Because something can be done about it! This is what chiropractors do for a living. When patients see chiropractors, they think we’re just adjusting their spine. However, what chiropractors do is look deeper and physically adjust the nervous system to remove any nerve interference and restore the body and nervous system to optimal functioning levels. Chiropractors do this by applying a series of high-velocity, low-amplitude adjustments to the area affected which will in hand take care of misaligned vertebra and further remove nerve root pressure. Noticed that we used the term series? Chiropractic treatment is not a one and done protocol, but rather, think about it as a long systemic process and investment to better health.

In most circumstances, chiropractic manipulation is not a one and done process. Spinal correction and nerve regeneration takes a long time to achieve. The biggest advantage of our facility is having two trained doctors specializing in disc and neuropathy treatment. We have successfully treated these conditions, preventing thousands from attempting more unnecessary, drastic measures such as opioids, injections, and surgery. Non-surgical spinal decompression and/or neuropathy management might be the answer to many questions people ask all the time. We know because we see and hear it every day. 

We hope that you learned a little bit today about the human spine and why the body reacts the way it does. We know this was probably a lot to absorb but it’s crucial information to know as it gets patients to the chiropractor faster and addresses serious issues that should not be taken lightly. Remember, the longer someone waits, the longer it takes to treat the issue. If you or someone you know is experiencing generalized pains or more severe symptoms like what we discussed in this week’s blog, please call us at (724) 547-3377 and checkout our website at www.drlarrywilkinsspinalcare.com for more content on similar conditions and treatment options.

Yours In Health, 

Larry E. Wilkins, DC

Brian M. Steinert, DC