This section is from the book "Applied Anatomy: The Construction Of The Human Body", by Gwilym G. Davis. Also available from Amazon: Applied anatomy: The construction of the human body.
The most frequent site of the incision in cases of cut throat is between the hyoid bone and thyroid cartilage. If above the hyoid bone, the incision will divide the mylohyoid, geniohyoid, geniohyoglossus, and hyoglossus muscles, and perhaps the digastric and stylohyoid. If it goes far back it may wound the submaxillary gland or duct, the facial or lingual arteries and veins, and the hypoglossal nerve. The commencement of the anterior jugular will certainly be divided and the external jugular may also be wounded. The cut passes through the base of the tongue and the upper portion of the epiglottis. The tip of the epiglottis is sometimes entirely cut off. If in the thyrohyoid space, the incision passes a short distance above the vocal cords. The sternohyoid, omohyoid, and thyrohyoid muscles are divided. If prolonged backward the pharynx will be opened and perhaps the arytenoid cartilages wounded. The superior thyroid artery is likely to be cut. This is the vessel most often divided in suicidal wounds. The carotid arteries and internal jugular veins are deep and far back, lying under the edge of the sternomastoid muscle, and are rarely wounded.
Fig. 187. - Exposing the oesophagus.
If these are cut, death usually rapidly ensues from hemorrhage. The superior laryngeal nerve may be injured as it pierces the thyrohyoid membrane. This nerve is sensory and its division is followed by anaesthesia of that half of the larynx to which it is distributed. This favors the entrance of food and liquids into the larynx and so may cause a fatal septic pneumonia. If through the thyroid cartilage the incision may wound the vocal cords. They lie just beneath the most prominent part of the thyroid cartilage and just below its median notch. If through the trachea, the incision may wound the thyroid gland, which reaches from about the sixth ring of the trachea to the oblique line on the thyroid cartilage.
Bleeding from the wounded thyroid, if the gland is normal in size, is not likely to be excessive. Below the cricoid cartilage the oesophagus may be wounded, above it the pharynx may be opened. The two large sternomastoid muscles being put on the stretch tend to protect the large vessels beneath. Suppuration not infrequently accompanies these wounds of the neck in which the air and food passages are involved and may give rise to collections of pus which may travel between the fascias, as previously described. In treatment it is customary to cleanse the wounds and approximate the various injured tissues as carefully as possible, and feed by a stomach tube.