The neck joins your head to your body. Necks come in all shapes and sizes, like a ballerina graciously moves her neck during her dance, or a weightlifter whose neck seems shorter due to the shear size of his Trapezius muscles. Even though these necks appear different, both have the same architecture, just like yours.
The vertebrae are named and counted from the top down. C1 (atlas, named after the Titan warrior condemned to carry the heavens on his shoulders by Zeus) and C2 (axis) are unique in the pivot joint that they form. This pivot joint enables rotary movement, turning your head from side to side, which comes in handy when following the ball during a tennis match.
C3 to C7 look fairly similar. The vertebral bodies have discs in between them. The rest of the vertebrae (lamina, transverse and spinous processes) fit together snugly, like lego pieces stacked on top of each other to create a tower. These “snug fits” are the facet joints (zygapophyseal joints). You have one on each side of a vertebra, where the one on top slide on the one below. A thing of beauty really, if it allows the movement is was designed for.
These facet joints work together to move the neck to look up and down or bend the ear to the shoulder, like when you squeeze your phone to your ear. All these joints need to work in harmony to allow full, pain free movement.