nielemärefleksin

Nielemärefleksin, commonly known in English as the gag reflex, is a protective reflex of the oropharyngeal region triggered by stimulation of the soft palate, oropharynx, or posterior tongue. Its primary purpose is to prevent choking and aspiration by coordinating airway closure and pharyngeal contraction.

Physiology: The afferent limb is mediated mainly by the glossopharyngeal nerve (cranial nerve IX), which transmits sensory information to the nucleus tractus solitarius in the medulla. The efferent limb is carried by the vagus nerve (cranial nerve X) via the nucleus ambiguus, producing contraction of pharyngeal muscles and elevation of the soft palate, often accompanied by brief apnea and coughing.

Clinical relevance: In healthy individuals the gag reflex protects the airway during swallowing and irritation of the oropharynx. Some people have a hypoactive or absent gag reflex, which can increase aspiration risk, while others have a hyperactive reflex causing persistent coughing or retching. The reflex can be suppressed by central nervous system injury, severe illness, or anesthesia, which can affect airway management during procedures requiring access to the oropharynx.

Testing and variation: Clinicians assess the gag reflex by gentle touching of the posterior oropharynx with a sterile tongue depressor or cotton-tipped swab. Responses may vary by age, sensation, and neurologic status. In infants and young children, eliciting the reflex is common, but its presence is not a sole indicator of safe swallowing.

Management and notes: For individuals with hypersensitive reflex, desensitization and swallow therapy may help in dysphagia or anxiety-related choking. In clinical settings, the gag reflex may be diminished or absent to facilitate procedures; care is taken to protect the airway. The gag reflex is a widely studied example of a brainstem reflex arc involving cranial nerves IX and X.