When you do a lot of yoga, you hear a lot of anatomical terminology, some of which is scientific and some of which is far from it. For example, yoga instructors like to refer to your "sit bones," which I had never heard of before my first yoga class. A scientist would call these bones the ischial tuberosities, but I guess we can't all be scientists. If you want to use common language for an anatomical part, that doesn't bother me any.
What does bother me is when you use the wrong anatomical term for an anatomical part--the most frequent culprit being vertebrae.
The vertebrae, collectively, are the bones that form the spinal column. Because the term comes from Latin, and latin plurals are wack, it should surprise no one to find out that vertebrae is a plural form of the word vertebra. Therefore, each individual bone in the spine is called a "vertebra."
So every time a yoga teacher tells you to rise from your forward fold "one vertebrae at a time," an ancient Roman grammarian rolls over in his grave. Probably most modern medical professionals would do so too, if they were not still alive.
So my advice to all those who, in their line of work, need to refer to the bones of the spinal column, is to either stop that and say something sensible like, "Rise to standing starting with your head and working your way down your back," or else get your Latin plurals straight. It's "one vertebra at a time!"