4期モデル(four stage model)で説明される。

口腔準備期:
嚥下できる状態になるまで口腔内に液体が保持される時期。液体が咽頭に漏れないように、舌後方部と軟口蓋によって口峡部は閉鎖されている。

口腔送り込み期:
液体を口腔から咽頭へ送り込む時期。
舌は前方から後方へと口蓋に接触し、舌根部は下降する。軟口蓋が挙上し 口峡部が開く。

咽頭期:
液体が咽頭を通過する時期。喉頭挙上、喉頭閉鎖、咽頭収縮、食道入口部開大が生じる。

食道期:
液体が食道から胃へと送り込まれる時期。

Four stage model is applied.

Preparatory stage:
The stage during which a thin liquid is hold in the oral cavity until ready for starting swallow.
The fauces is closed by tongue and soft palate to shut off the oral cavity from the pharynx.

Oral stage:
The stage during which the thin liquid is transported from the oral cavity to the pharynx. The tongue begins touching from the anterior to posterior part while the tongue base begins descending. At the same time, soft palate is lifted backward to open the oropharyngeal isthmus.

Pharyngeal phase:
The stage during which the thin liquid passes though the pharynx. Larynx elevates, laryngeal close, pharynx contracts, and UES opens.

Esophageal phase:
The stage during with the thin liquid is transported downward and reach the stomach.