Ataxic respirations are caused by damage to which part of the brain stem?

• A. Pons
• B. Midbrain
• C. Medulla
• D. Cerebellum

Answer: (C)

Ataxic breathing signals failure of the brainstem’s automatic control of respiration. The medulla oblongata houses the primary centers that set the breathing rhythm (the dorsal and ventral respiratory groups). When this area is damaged, the rhythmic drive becomes irregular and unpredictable, producing breaths of varying depth and pauses or even apnea. This is the classic pattern of ataxic (Biot-like) respiration.

In contrast, injury to the pons often disrupts the smooth transition between inhalation and exhalation and can cause apneustic or cluster breathing, rather than the irregular, completely erratic pattern seen with medullary damage. The midbrain and cerebellum aren’t the primary generators of automatic breathing rhythm, so damage there typically doesn’t produce this pattern.