Tongue movement of the cat during lapping.

The movements of radio-opaque markers in the tongue were recorded cine-radiographically. The animals were fed bariumized milk, with or without a thickening agent to increase the viscosity. The movements of the tongue markers relative to the palate were roughly elliptical and resulted from the summation of at least three components: simple movement produced within the tongue, movement imposed on the tongue by hyoid movement and movement imposed on the tongue-hyoid complex by jaw movement. Relative to the palate, the anterior markers protracted high and retracted low, whereas the posterior markers did the reverse. The movements could be explained as having utility for the intra-oral transport of liquid by two mechanisms. The transported liquids then accumulated between the soft palate and the tongue prior to swallowing. The swallow appeared as a brief interruption in the jaw-opening phase of otherwise standard lapping cycles.