VERTEBRAL COLUMN ANATOMY (1/2)

your spine also called your backbone or vertebral column is composed of 33 Bones called vertebrae which provide your body with support and protect your spinal cord from injury the vertebrae can be divided into five groups cervical thoracic lumbar sacral and the coccyx each of which has unique features suited to its functions there are seven cervical vertebrae numbered C 1 to C 7 12 thoracic vertebrae numbered T 1 2 T 12 5 lumbar vertebrae numbered l1 to l5 5 sacral vertebrae numbered s 1 to s 5 and the coccyx the upper 24 vertebrae are articulating separated

by intervertebral discs the sacral vertebrae and the bones of the coccyx are fused the cervical vertebrae which are the vertebrae of your neck support your head which weighs around 10 to 13 pounds c1 and c2 are specialized vertebrae that allow for the greatest range of motion of all the vertebrae c1 is called Atlas after the man from Greek mythology who held up the earth it is ring shaped and attaches directly to your skull this vertebra allows you to nod your head see - while the axis serves as an axis about which c1 pivots allowing you

to shake your head when saying no c1 is able to pivot on this vertebra thanks to a specialized process called the dens or oven toy process the thoracic vertebrae which are the vertebrae of your mid and upper back hold the ribcage and protect your heart and lungs they have a limited range of motion the lumbar vertebrae which are the vertebra of your lower back bear the weight of your upper body and are larger in order to support the stress especially when you lift something heavy the sacral vertebrae connect your spine to your hip bones these

vertebrae are fused together together with your hip bones they form the pelvic girdle the coccyx or tailbone is made up of four fused bones which provide attachment points for ligaments and muscles of the pelvic floor now let's cover the parts of a vertebra a vertebra has three parts the body vertebral arch and the processes the body bears weight the vertebral arch houses the spinal cord and the processes allow for muscle attachment the vertebral arch is made up of two supporting pedicles and two laminae the space inside which houses the spinal cord is called the vertebral

foramen under each pedicle spinal nerves exit and pass through the intervertebral foramina seven bony processes arise from each vertebral arch to form facet joints and processes for muscle attachment facet joints allow for back motion each vertebra has two pairs of facet joints one pair connects to the vertebra above and one pair that connects to the vertebra below there is also a pair of transverse processes and a spinous process between the vertebra are the intervertebral discs which provide cushioning and prevent the bones from rubbing together note that there is no intervertebral disk between c1 and c2

disks are composed of an annulus which is made up of several layers or lamina of fibrocartilage criss-crossing fibrous bands that attach between the bodies of the vertebrae above and below and a gel filled center called the nucleus the nucleus distributes the pressure evenly within each disk during compression the nucleus is full of proteoglycans large molecules with sugar subunits that are very hydrophilic this structure swells with water unless it experiences constraints from the surrounding tissues hence the nucleus absorbs fluid at night or when you are lying down and then this fluid is pushed out during the

day when you are upright and pressure is applied to the intervertebral discs we shorten as we age because the discs lose the ability to reabsorb fluid during rest and they flatten and become more brittle if you liked this video please like and subscribe it would help me make more videos and make sure to comment with any topics you'd like me to cover in future videos also it would be really nice if you could support me on patreon thank you