hi this is Peter from Anatomy Zone and in this video we're going to take a look at the anatomy of the vertical column you can now interact with an annotated version of the 3D model that I use in these videos which are available on my website at anatomyzone.com check out the video description for the link and let me know what you think in the comments below the vertical column is part of the axial skeleton and functions to support the body's weight and encloses and protects the spinal cord within the spinal canal it provides a framework for the attachment of several muscles the extrinsic back muscles are involved in moving the upper Limbs and ribcage whereas the intrinsic back muscles are important in maintaining posture and in moving the vertical column itself the vertical column consists of 24 articulating vertebrae and then the sacrum and coccyx which consist of nine fused vertebrae so there are seven cervical vertebrae 12th thoracic 5 lumbar 5 sacral and three to four coccygeal in between each vertebrae there is an intervertebral disc which forms a fibrocartilaginous joint allowing slight movement between the vertebrae and functioning as a shock absorber for the spine the intervertebral disc consists of a tough outer fibrous ring called the annulus fibrosis and a gelatinous center the nucleus pulposus degenerative changes or mechanical trauma can cause tears in the outer annular fibrosis squeezing out the nucleus pulposus which can then exert direct pressure on the spinal cord itself or more commonly on the nerve Roots as they leave the spinal cord this is known as a disc herniation and I'll do a more detailed tutorial on the clinical anatomy of this topic separately the vertebrae are identified by a letter and a number so for the cervical vertebrae you have vertebrae C1 to seven for the thoracic vertebrae you have T1 to T12 and for the lumbar vertebrae you have L1 to L5 this naming convention is useful when referring to anatomical landmarks and when referring to spinal nerves with regard to the spinal nerves these are named according to the level at which they exit the vertical column within the cervical spine although there are only seven vertebrae there are actually eight spinal nerves I've just rotated the model around and you can see how the first cervical spinal nerve exits above the first cervical vertebrae C1 as another example if we look here at this vertebra in the lumbar region we can see where the lowest rib articulates so this must be the 12th rib and therefore articulates with the 12th thoracic vertebra we can count down L1 L2 and see that this is the L3 vertebra we can alternatively count back from the fifth lumper vertebra starting from above the sacrum so L5 L4 and then L3 I've just zoomed in a bit and here you can see this nerve the L3 spinal nerve exiting from between the L3 and L4 vertebrae through this Gap the intervertebral foramen in terms of using spinal levels for reference points to anatomical landmarks a clinical example would be in the context of performing a lumbar puncture in adults we know that the spinal cord terminates at the conus medallarus which lies at approximately the L1 to L2 level we can palpate the iliac crests to top of which we now lie at approximately The L4 level from here we can identify the spinous process of L4 and a safe entry point for the needle to avoid damage to the spinal cord with regard to other examples of anatomical landmarks an example would include the sternal Angle of Louis or the manubriosternal junction which lies at the T45 level this level determines the thoracic plane an artificial horizontal plane which divides the superior mediastinum from the inferior mediastinum and at which there are a few key anatomical landmarks such as the start and end of the outer catch and the bifurcation of the trachea as you've seen the adult vertical column is curved there are four curvatures the cervical lordosis which is convex anteriorly the thoracic kyphosis which is convex dorsely the lumbarlordosis which is convex anteriorly and then you have the pelvic curvature which is concave anterility starting at the lumbosacral junction and ending at the coccyx in neonates the vertical column just has one fixed kyphotic curvature which is concave anteriorly and known as the primary curvature the other lordotic curvatures are progressively developed later in life as shown in this diagram and are known as secondary curvatures in terms of movements of the vertical column these vary according to the spinal level but there are four movements which are possible flexion extension rotation and lateral flexion these movements are limited by the morphology of the joints between the vertebrae the presence of ribs in the thoracic region and the ligamentous structures there are two more specialized joints within the cervical spine which I'll just quickly mention The Joint between the skull and the first cervical vertebrae is the atlanto occipital joint it's given this name because the first vertebra is also referred to as the atlas and the second vertebra is known as the axis the part of the skull it articulates with is the occipital bone hence the atlanto occipital joint I've just rotated posteriorly and you can see there are two articulations at the atlanta-occipital Joint which are synovial condyloid joints at this joint we get flexion and extension and a small amount of lateral flexion The Joint between the first and second vertebrae is known as the atlanto axial joint C1 is the Atlas and C2 is the axis hence the name this is a complex joint which consists of a specialized synovial pivot joint formed between the odontoid peg of C2 and the anterior arch of C1 this unique anatomical configuration enables rotational movement so that completes this Anatomy tutorial on the vertical column don't forget to check out the 3D model which you can find on my website check out the link in the description below for more information thank you for watching