caudal

Caudal is an anatomical term derived from the Latin caudalis, meaning "of the tail." It denotes a position toward the posterior or tail end of the body in vertebrates, contrasted with cranial (toward the head). In neuroanatomy and general anatomy, caudal is used to describe structures toward the back when the body is oriented in standard anatomical terms, and it is applicable across species.

In zoology and anatomy, caudal describes directions along the body's axis. The term appears in phrases such as caudal fin in fish and caudal vertebrae at the tail end of the vertebral column. In the brain, caudal refers to posterior regions closer to the spinal cord, as opposed to cranial regions toward the rostrum.

In medicine, caudal describes a regional anesthesia technique known as caudal anesthesia or caudal block. This involves injecting anesthetic into the sacral canal via the sacral hiatus to provide anesthesia for surgeries below the umbilicus, especially in children.

In embryology and developmental biology, caudal refers to the tail end of the embryo. The caudal region is involved in the formation of the lower spine and tail structures; abnormalities in this region can lead to conditions such as caudal regression syndrome.

The term caudal is used in contrast to cranial and rostral, and remains a standard directional descriptor in anatomy, zoology, and clinical medicine.