Study on Tongue Coating 1985.6.21

Study on Tongue Coating 1985.6.21

When the vagus nerve is stimulated, salivary glands secrete large amounts of serous saliva; when the sympathetic nerve is stimulated, they secrete copious mucous saliva. The former facilitates cleaning of the tongue coating, while the latter promotes its accumulation. When individuals experience high fever, pain, anxiety, or stress, the sympathetic nervous system becomes hyperactive, leading to thicker tongue coatings. In patients with stroke, thick tongue coatings result from autonomic nervous system dysfunction and excessive sympathetic activity. Local circulatory disturbances, such as those seen in myocardial infarction, head trauma, or shock, often cause the tongue coating to thicken within 1–3 days for the same reason. If the condition improves after treatment, the tongue coating returns to normal within a week; if it worsens, the coating continues to thicken. Neurotransmission blockades can also alter the tongue coating—for instance, when procaine blockade induces nerve conduction blockage, thick tongue coatings form.