Nonbrain

Nonbrain is an informal term used to describe anything that is not brain tissue. It is not part of formal anatomical nomenclature; when precision is required, terms such as peripheral tissue, non-neural tissue, or non-brain structures are preferred.

The phrase appears in several contexts. In radiology and medical imaging, clinicians may label findings as “non-brain” to indicate that they lie outside the brain parenchyma, such as a mass in the skull, neck, or other regions. In comparative anatomy or developmental biology, writers may use “non-brain” to distinguish tissues or regions outside the brain, or to discuss contrasts with neural or brain-derived structures. In general writing, “nonbrain” may be used informally to refer to all bodily components other than the brain.

Limitations and cautions: because it is ambiguous, the term can generate confusion. Formal reports and textbooks typically replace it with specific terms for tissue type, location, and anatomical region, except when used with clear contextual qualifiers within a given document.

See also: brain, nervous system, peripheral nervous system, non-neural tissue, anatomy, radiology.