495. Moreover, such choirs are distinct. There are those that are assigned to the spontaneous [or involuntary function] of respiration, and there are those assigned to the voluntary [function] of respiration. Those choirs assigned to the spontaneous function of respiration are governed by the affections alone. Those assigned to the voluntary function of respiration are governed at the same time by those things which are intellectual and rational, and they are those who preside over speech, and also speak; that such is the case is because speech pertains to the lungs.* * In the Index (s.v. Pulmones) it is added - "There are also those who constitute the province of the trachea and larynx, and are serviceable to speech." See also AC 3351.