The human vertebral column is the vertebral column (backbone or spine) of the human skeleton, consisting of 24 articulating vertebrae and 9 fused vertebrae in the sacrum and the coccyx.he human vertebral column is the vertebral column (backbone or spine) of the human skeleton, consisting of 24 articulating vertebrae and 9 fused vertebrae in the sacrum and the coccyx.
ADA Clear Doorway widths. Two doors in series must have a minimum of 48â in addition to the width of the door(s) swinging into the space (so a 36â door swinging into a hall would require the hall to be a minimum of 7â-0â long before any other door could be placed, if the second door does not also swing into the hall).
For exterior doors, the minimum opening is 0.90 m when the door is open. For interior doors, the minimum opening is 0.80 m when the door is open. The minimum door opening can be 0.75 m if the access is straight or if the door can stay open by itself (fig. 5).