(3.32)

We’ll start by looking at the front front of the neck with just the skin and subcutanous tissue removed. We’ll remove the sternocleidomastoid muscles, and the clavicles, and we’ll also remove these slender muscles, the infrahyoid muscles. We’ll see them later. This is the thyroid gland. We’ll see it later too. For now, we’ll remove it.

Here’s the thyroid cartilage, here below it is the cricoid cartilage, hidden by the cricothyroid muscle. These two cartilages form the framework of the larynx. The thyroid cartilage is suspended from the hyoid bone, which is here, by the thyrohyoid membrane. Below, the cricoid cartilage is continuous with the upper end of the trachea.

Here on each side this sleeve of connective tissue, the carotid sheath, contains the major blood vessels of the head and neck. We’ll remove the carotid sheaths.

We’ll also remove the musculo-skeletal structures behind and below the larynx. Here’s the trachea, here’s the esophagus, here’s the lower part of the pharynx. To see the larynx from behind, we’ll remove the posterior wall of the pharynx.

Here’s the opening of the larynx, the superior laryngeal aperture. It faces almost directly backwards. The opening is formed in front by the epiglottic cartilage, on each side by this fold of soft tissue, the ary-epiglottic fold, and behind by two important structures that we’ll meet in a minute, the arytenoid cartilages. The space that’s lateral to the ary-epiglottic fold is the piriform recess. Here in front of the epiglottis is the back of the tongue. The space between the tongue and the epiglottis is the vallecula.

To see the larynx from inside we’ll look at a specimen that’s been divided in the mid-line. Here’s the epiglottis, here’s the ary-epiglottic fold. Here’s the divided thyroid cartilage, and the divided arch and lamina of the cricoid cartilage.

The important features of the wall of the larynx are this small side cavity, the vestibule, and these two folds in the mucous membrane, the vestibular fold above, and the vocal fold below. Just beneath the mucosa of the vocal fold is an important structure, the vocal ligament, which we'll see shortly.

Here’s the larynx in the living body, seen from above with an endoscopic camera. Here’s the epiglottis, here's the left ary-epiglottic fold. Here are the vestibular folds, here are the vocal folds, here between them, we’re looking down through the vocal opening into the trachea.

To get a preview of the muscles of the larynx, we’ll remove the mucous membrane from here, down to here. Some of the muscles of the larynx are visible here, others are hidden by the thyroid cartilage. We’ll see these muscles later in this section.