Protection of the Respiratory Tract*

The memory of Walter Jobson Home will be kept alive by the institution of this lecture. I am proud to be the first to deliver it, particularly as I remember a number of meetings at which his somewhat controversial observations gave life to the discussions. He was in appearance rotund and reminiscent of a character from Dickens; in intellect he was erudite and a good speaker. He was, in brief, a character. The respiratory tract, and particularly inflammatory lesions of the larynx, were of great interest to him; his inclination was toward pathology and away from operations, characteristics to be remembered and imitated. A keen supporter of the B.M.A. and President of a Section at the Meeting in Bradford, he also had the honour of giving the Semon Lecture in 1921. I have chosen as my subject: "Protection of the Respiratory Tract." Consideration of this problem allows no distinction to be drawn between the upper and lower respiratory passages, as frequently occurs in the education of medical students; the former is often classed as a special subject and the latter as part of general medicine, with confusing results. Since infections of the respiratory tract are among the most common of complaints, with the loss of a vast number of working days, it is important to have some understanding of the complicated physiological processes entailed. After a medical career devoted to the study of this subject 1 regret to find myself in some confusion, but 1 will attempt to outline certain aspects which I hope will serve as a basis for therapeutic principles. The respiratory tract must be considered from the nostrils to the alveoli, and in addition the peculiar anatomy of man makes it essential to include the mouth and pharynx, since mouth-breathing is frequently used, especially during speech. It will be best to consider the various dangers against which protection must be afforded, and foremost among these is the avoidance of entry of water and food into the trachea and bronchi; this is a primitive function which concerns lungbreathing fish, amphibians, reptiles, birds, and mammals. When the pulmonary apparatus was evolved it was essential to provide a protective valve at its origin from the pharynix; this valve is the larynx, often considered, incorrectly, to function solely as the organ of voice. *The Walter Jobson Horne Memorial Lecture delivered at the Adjourned Annual General Meeting of the British Medical Association, Sheffield, July 20, 1961.