The Anatomy of the Spine

The spine is a large yet unusual shaped structure that would appear to be very complex...  Well that's because it is!  Our spine offers us movement, support, protection and shape to our being.  It runs from the base of our cranium otherwise known as our occipital bone down to our pelvis.  The spine is made up of five vertebral regions that all consist of tiny vertebrae that form the regions of our spine.  What's a vertebrae you may be asking yourself?  A vertebrae is a bony prominence structure that form the region of our spinal cord.   It consists of a spinous process which protrudes out of the spine and can be palpated on the posterior (back) surface of our torso/body.  The spinous process allows muscles and ligaments to attach onto each vertebra. Each vertebrae also consists of a transverse process align with the other on each side, this too offers the ability for muscles and ligaments to attach to the transverse processes.  Finally the vertebrae also consist of a spinal foramen which transport signals necessary for muscle movements within the spinal cord and a vertebral body that forms the larger part of the structure offering support to each vertebrae.

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The first region of our spine consists of seven vertebrae and is known as the cervical region.  This region allows the following movements;  extension, flexion, side flexion, rotation, protraction and retraction.  Our cervical spine has a distinguished curve in it which is known as a lordotic curve or otherwise simply put as lordosis.  A lordotic curve would appear as a concave shaped curve, similar to the letter 'C'.  Our curves in our spine are formed through child development (womb - crawling - standing).  The cervical region supports the skull as it is the first region that lays directly beneath it.  The first vertebrae of the region C1 (atlas) name stems from the Greek god atlas and the thought that he carried the globe above his shoulders, in this case C1 being the first vertebrae in contact with the occipital bone is supporting the globe (brain) of the head.  The second vertebra of the region C2 name stems from the wide variety of movements within the region.  It is these two vertebrae that connect the skull to the spine allowing for greater motion of the neck.

Then we have our thoracic region which is our largest vertebral column consisting of twelve vertebrae.  However this column only allows for four movements with the absence of protraction and retraction. Within the thoracic spine our ribs attach, giving our heart and lungs protection thus adding support to sustain the cervical spine and skull.  Within this column another curve appears this time more convex, almost like a backwards 'C'.  This is known as a kyphotic curve or sometimes put as kyphosis.  Great, we know what each curve is, but what do they do?  Well imagine the spine completely straight without the curves, we would appear very upright and rigid, this would make it virtually impossible to build support or structure a foundation to your body.  Therefore essentially the curves allow for mobility within the spine and a structure for us to build muscle and support for our anatomy.  However if these curved structures became abnormal and protruded in areas such as the thoracic spine, causing a person to become hunched over in their upper back, this is what is medically referred to as thoracic hyperkyphosis.  These sort of terms exist because of muscle imbalances and bad posture.

The spine of the lower back is called the lumbar spine and this is the strongest of all the vertebral regions offering us the majority of our support.  These vertebrae are thicker than usual as they have to support the two largest regions of the spine and the skull.  Additional support through the attachment of large muscles such as the multifidus, longissimus, and spinalis palpated on the posterior surface of our spinal cord stabilise and aid the spine in rotation.  If these muscles become hypotonic it can have detrimental effects, causing severe pain and misalignment to your lumbar spine.  A final lordotic curve appears in this region increasing the motion available, assisting movements such as, flexion, extension, side flexion and rotation.  However misalignment of this region can cause hyperlordosis, which is due to the muscle imbalances and bad posture causing things such as 'duck butt' when the butt becomes distal.  This spine allows us to bend over flexing at the hip and stretch/reach extending at the hip.  Vital activities in an average persons life.

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Finally we have our sacral spine and coccygeal spine.  In the sacral column are five vertebrae that fuse together to form the sacrum, which is a triangular shaped bone situated below the lumbar region.  This section of the spine is last to develop and only fully develops during early adulthood in which it articulates to the pelvic girdle.  The coccygeal spine is palpated infra to the sacral region and   has four vertebrae.  These vertebrae fuse together to form the coccyx.  This area of the spine is full of many tendons, ligaments, and nerves and can cause much discomfort when damaged.   Ever sat down too fast or too hard and had a burning excruciating pain around your lower back?  This would be inflammation to your coccyx region.  It is commonly referred to as the 'tailbone'.  Research and studies conducted suggest that before the evolution of our existence into human beings, it is believed that we had tails that over the course of time and nature fell off.

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This is an intervertebral disc found between each vertebra and acts as a shock absorber to the forces applied to our spine.  These consist of a nucleus, and a membrane known as annulus fibrosis.  The annulus fibrosis is a spongy outer casing that forms round the nucleus pulposus protecting it from the forces applied to the spine, however sometimes when we apply too much force to one side of the body the nucleus pulposus (liquid like substance) can burst out the other side causing excruciating pain, this is known as herniation.

In summary, anatomically the spine is our most important joint as it occupies our central nervous system (CNS) which consists of the spine and the brain and if damaged can have detrimental effects on the functioning of our musculoskeletal system.  This is vital to everyday activities and movements, movements such as the ones mentioned above.  Discrete skills such as talking and side flexion of the neck can become limited as our spine contains all the nerves that transmit signals throughout our body as a direct pathway via the brain.