SECTION 4. THE PHARYNX (FIG. XVIII, A, B, C). By the term "pharynx" we understand that part of the alimentary canal which is placed behind the nose, mouth and larynx. Above it is connected with the nose through the two large apertures called posterior nares; below it is continuous with the œsophagus, and attached to the larynx. It is divisible into three portions, the middle of which is called oro-pharynx (Fig. XVIII, B), the upper portion, naso-pharynx (Fig. XVIII, A), and the lower portion laryngo-pharynx (Fig. XVIII, C). SECTION 5. THE LARYNX (VOICE BOX; FIGS. XIX, XX, XXI). The larynx is a hollow body composed of cartilages which are united by ligaments. The cartilages consist of the shield or thyroid cartilage, the ring or cricoid cartilage, the two pyramid or arytenoid cartilages, the epiglottis (the cover of the larynx), and of four more which, however, are not of so great importance. It is lined with mucous membrane, surrounded by muscles, and its function is to admit the air to the lungs, but more particularly to produce the voice. It forms the upper part of the windpipe (Fig. XIX), is connected with it below, and is situated at the upper and fore part of the neck, beneath the SECTION 4. THE PHARYNX (FIG. XVIII, A, B, C). By the term "pharynx" we understand that part of the alimentary canal which is placed behind the nose, mouth and larynx. Above it is connected with the nose through the two large apertures called posterior nares; below it is continuous with the œsophagus, and attached to the larynx. It is divisible into three portions, the middle of which is called oro-pharynx (Fig. XVIII, B), the upper portion, naso-pharynx (Fig. XVIII, A), and the lower portion laryngo-pharynx (Fig. XVIII, C). SECTION 5. THE LARYNX (Voice Box; FIGS. XIX, XX, XXI). 1 The larynx is a hollow body composed of cartilages which are united by ligaments. The cartilages consist of the shield or thyroid cartilage, the ring or cricoid cartilage, the two pyramid or arytenoid cartilages, the epiglottis (the cover of the larynx), and of four more which, however, are not of so great importance. It is lined with mucous membrane, surrounded by muscles, and its function is to admit the air to the lungs, but more particularly to produce the voice. It forms the upper part of the windpipe (Fig. XIX), is connected with it below, and is situated at the upper and fore part of the neck, beneath the root of the tongue, with which it is connected by IMAGE OF THE LARYNX AND SURROUNDING PARTS, TWICE THE ACTUAL SIZE. 1, base of the tongue; 2, epiglottic frænum, or middle glosso-epiglottic ligament; 3, vallecula; 4, epiglottis; 5, cushion of the epiglottis; 6, lateral glosso-epiglottic ligament; 7, anterior, and 8, posterior commissure of the larynx; 9, rima glottidis, 10, vocal cord 11, ventricular fold; 12, ventricle; 13, posterior vocal process; 14, arytenoid cartilage; 15, supra-arytenoid cartilage; 16, cuneiform cartilage; 17, ary-epiglottic fold; 18, posterior laryngeal wall, entrance to the oesophagus; 19, pyriform sinus; 20, hyoid fold of mucous membrane. [Explanation to Fig. XIX, page 49] A CONNECTED VIEW OF THE HYOID-BONE, THYROID BODY, LARYNX, WINDPIPE WITH ITS RAMIFICATIONS, AND LUNGS. I is the epiglottis, 2 the hyoid or tongue-bone; 1, 4, 5 and 6 show the larynx; 4 is the thyroid cartilage; 5, 5 are the superior horns of the thyroid cartilage, and 3, 3 the thyro-hyoid ligament; 6 is the cricoid cartilage, 9 the bifurcation; at 8, 8, 8 are seen tracheal cartilaginous rings; 7 shows the thyroid body, 10 the left bronchus and II the right bronchus. A, A show in outline the two lobes of the left lung into which the bronchial tubes a, a are seen to enter. The three lobes of the right lung are indicated by B, B, B, with the corresponding bronchial tubes b, b, b. In the upper lobe of the right lung is indicated in outline the manner in which the bronchial tubes subdivide into smaller and smaller tubes which finally terminate in air-passages and air-cells of the primary lobules. 20 |