The mammillary processes in the equine spine extend from which vertebra to which?

The mammillary processes in the equine spine extend from which vertebra to which?

• A. T15-L5
• B. T14-L4
• C. T16-L6
• D. T17-L7

Answer: (C)

Mammillary processes mark the thoraco-lumbar junction and serve as attachment points for deep back muscles that stabilize the spine. In the horse, this transitional region runs from the 16th thoracic vertebra down to the 6th lumbar vertebra, so these processes extend from T16 to L6. The cranial boundary is at the junction after the 16th thoracic vertebra, and the caudal boundary ends at the last lumbar vertebra before the sacrum, which is L6. This explains why the range is from the 16th thoracic to the 6th lumbar vertebra.

Mammillary processes mark the thoraco-lumbar junction and serve as attachment points for deep back muscles that stabilize the spine. In the horse, this transitional region runs from the 16th thoracic vertebra down to the 6th lumbar vertebra, so these processes extend from T16 to L6. The cranial boundary is at the junction after the 16th thoracic vertebra, and the caudal boundary ends at the last lumbar vertebra before the sacrum, which is L6. This explains why the range is from the 16th thoracic to the 6th lumbar vertebra.