Entry 6

Foreign Bodies in Laryngopharynx

The laryngopharynx, as called hypopharynx,is one of three sections of the pharynx. The other two are the oropharynx (mesopharynx) and nasopharynx (epipharynx). The laryngopharynx is the section of pharynx that connects the throat to the esophagus; lying inferior to the epiglottis. The superior boundary of the laryngopharynx is the hyoid bone and is the pathway for both air entering the larynx and food & drink entering the esophagus. When the two battle over which one will have the right away, the food & drink wins most of the time. The laryngopharynx is innervated by the pharyngeal plexus and is lined with stratified squamous epithelium.

The laryngopharynx is the location of halting foreign objects in the throat due to the piriform sinus. The piriform sinus is a recess located on either side of the laryngopharynx, and just deep to the mucous membrane of this fossa lie the the internal laryngeal nerve a branch of the superior laryngeal nerve. When objects like chicken bones or fish bones get caught in the piriform sinus there is a risk of puncturing through the mucous membrane and causing damage to the internal and superior laryngeal nerves. Injury to these nerves could cause anesthesia of the laryngeal mucous membrane as far inferiorly as the vocal folds; causing lose of the ability to speak. Until recently this trauma would be permanent but through medical advancements doctors are able to repair the laryngeal nerves.

http://en.wikipedia.org/wiki/Human_pharynx#Laryngopharynx

Enlargement of Thyroid Gland

            The thyroid gland is located in the anterior neck at the same level of C5-T1 vertebrae and the second & third tracheal rings.  The thyroid gland is one of the largest endocrine glands in the body, and controls how quickly the body uses energy, makes proteins and controls how sensitive the body should be to other hormones. The gland produces several hormones: triiodothyronine (T3) and thyroxine (T4) both of these hormones regulate the rate of metabolism, and are synthesized by both iodine and tyrosine. The thyroid also produces calcitonin which plays a role in calcium homeostasis.

            The non-neoplastic and noninflammatory enlargment of the thyroid gland is called a goiter. This is a result of a lack of iodine in the diet. It is common in certain parts of the world where the soil and water are deficient in iodine. The goiter can compress the trachea, esophagus, and recurrent laryngeal nerves. Depending on the size of the goiter determines the treatment. Small goiters are usually monitored but most of the time left alone. Large goiters, compressing the trachea and/or esophagus, need surgical intervention.

http://en.wikipedia.org/wiki/Thyroid

Trauma to the Recurrent Laryngeal Nerves

            The recurrent laryngeal nerves (RLN) branch from cranial nerve X, vagus nerve. The RLN branches into the right and left RLN each following its own distinctive path. The right RLN loops inferior to the right subclavian artery at approximately the T1-T2 level. The left RLN loops inferior to the arch of the aorta at approximately the T4-T5 vertebral level. Both nerves ascend to the thyroid gland, traveling through the tracheo-esophageal groove, innervating the trachea, esophagus, and all the intrinsic muscles of the larynx except the cricothyroid.

Trauma of the recurrent laryngeal nerves can be a result from a surgical procedure, pressure from associated blood vessels, or from blunt force trauma to the neck. The right RLN is intimately related to the inferior thyroid artery and its branches. The nerve can cross this vessel from different directions in different people causing a possible problem during surgery. The left RLN is a little more distinctive during surgical procedures because of its more vertical ascent from the superior mediastinum, and blood vessels. The closer to the inferior aspect of the thyroid gland, the more convoluted the left RLN becomes. Hoarseness is the most common result of trauma; usually pointing toward unilateral RLN injury. Temporary aphonia or disturbance of phonation and laryngeal spasms may also occur. Vocal rest is the usually treatment for unilateral trauma to the RLN.  

http://en.wikipedia.org/wiki/Recurrent_laryngeal_nerve