Fig. 148.—View of the Cartilages in front project and form the lages and Ligaments of the “Adam’s apple,” plainly seen and Larynx. (Anterior view.)
- A, hyoid bone;
- B, thyro-hyoid membrane;
- C, thyroid cartilage;
- D, erico-thyroid membrane;
- E, cricoid cartilage, lateral ligaments seen on each side;
- F, upper ring of the trachea.
- (“Adam’s apple” is in the V-shaped groove on a line with B and C.)
The larynx has for a framework two cartilages, the thyroid and the cricoid, one above the other. The larger of these, called the thyroid, from a supposed resemblance to a shield, consists of two extended wings which join in front, but are separated by a wide interval behind. The united edges in front project and form the “Adam’s apple” plainly seen and easily felt on most people, especially on very lean men.
Above and from the sides rise two horns connected by bands to the hyoid bone from which the larynx is suspended. This bone is attached by muscles and ligaments to the skull. It lies at the base of the tongue, and can be readily felt by the finger behind the chin at the angle of the jaw and the neck (sec. 41 and Fig. 46). From the under side of the thyroid two horns project downwards to become jointed to the cricoid. The thyroid thus rests upon, and is movable on, the cricoid cartilage.
The cricoid cartilage, so called from its fancied resemblance to a signet-ring, is smaller but thicker and stronger than the thyroid, and forms the lower and back part of the cavity of the larynx. This cartilage is quite sensitive to pressure from the fingers, and is the cause of the sharp pain felt when we try to swallow a large and hard piece of food not properly chewed.
Fig. 149.—Diagram of a Sectional of Nasal and Throat Passages.
- C, nasal cavities;
- T, tongue;
- L, lower jaw;
- M, mouth;
- U, uvula;
- E, epiglottis;
- G, larynx;
- O, œsophagus.