The number of vertebrae in a human is __________.

The vertebral column in an adult human consists of $26$ serially arranged units called vertebrae.

The distribution of vertebrae is as follows:
Cervical vertebrae: $7$
Thoracic vertebrae: $12$
Lumbar vertebrae: $5$
Sacral vertebra: $1$ (fused from $5$ bones)
Coccygeal vertebra: $1$ (fused from $4$ bones)

Total number of vertebrae = $7 + 12 + 5 + 1 + 1 = 26$.

Answer: $26$