Dr. Manions Larynx Stuff:

The hyoid bone is connected to the thyroid cartilage by the thyrohyoid membrane. There are natural openings in the thyrohyoid membrane, which is an opening for the internal laryngeal nerve and the superior thyroid artery to enter the vestibule of the larynx. Connecting the thyroid cartilage to the cricoid cartilage is the cricothyroid ligament. Connecting the cricoid cartilage to the first tracheal ring is the cricotracheal ligament. NOTE: THE THYROID CARTILAGE ACTUALLY FORMS A SYNOVIAL JOINT WITH THE CRICOID CARTILAGE. CLINICAL NOTE: THE CRICOTHYROID LIGAMENT IS THE COMMON PLACE TO DO AN EMERGENCY CRICOTHYROTOMY! (This is because there are no major nerves or blood vessels in this area.) CLINCAL NOTE: TRACHEOTOMIES ARE DONE BETWEEN THE SECOND AND THIRD TRACHEAL RINGS. CLINICAL NOTE: TRACHEOSTOMY IS PERMANENT!!! THE TRAHEAL MUCOSA IS BROUGHT INTO CONTINUITY WITH THE SKIN AND SUTURED TOGETHER. The tracheal rings are NOT complete rings so posterior to them is the posterior fibromuscular wall of the trachea which fits against the esophagus. The arytenoid cartilage that sits on the cricoid cartilage has a vocal ligament attached on its anterior portion and also attached anteriorly to the thyroid cartilage. This connection forms an elastic cone (traps air). Rotational movements of the arytenoid cartilage made by the instrinsic laryngeal muscle causes changes in the space between the vocal cords (rema glottidis). Tilting of the cricoid cartilage on the thyroid cartilage (made by the cricothyroid muscle) grossly adjusts the tension in the vocal ligament. The vestibule of the larynx is from the epiglottis down to where the laryngeal ventricle starts. If you remember from histo the fold superior to the ventricle is the vestibular (a.k.a. false vocal fold) and the fold inferior to the ventricle is the vocal fold (a.k.a. true vocal fold). Remember that the cricoid cartilage is the only one with a complete cartilaginous ring. The area inferior to the vocal fold is the infraglottic cavity. Underlying the vestibular and vocal folds are the vestibular and vocal ligaments. The vocalis muscle (intrinsic) runs right along the vocal ligament. Remember the cricothyroid muscle (intrinsic) I mentioned before that provides tension to the vocal ligament It is innervated by the external laryngeal nerve (branch of the vagus nerve). NOTE: EVERY OTHER INTRINSIC LARYNGEAL MUSCLE IS INNERVATED BY THE RECURRENT LARYNGEAL NERVE!!! Definition: Extrinsic laryngeal muscles are any muscles extrinsic to the larynx that elevates it of depresses it. (i.e. suprahyoid and infrahyoid group of muscles) Definition: Intrinsic laryngeal muscles are muscles that originate within the larynx and insert within the larynx. He kept saying over and over that the aryepiglottic fold TIGHTENS a bit due to mucles within the fold but it doesnt completely close the passageway into the larynx!!!!! The rema glottidis, however, does close completely depending on what the individual is doing. During respiration it is open! The glossopharyngeal nerve provides BOTH general and special sense to the posterior 1/3 of the tongue (pharyngeal tongue). Innervation: The Inferior Laryngeal Nerve provides sensory fibers to the vestibule. The Recurrent Laryngeal Nerve provides sensory to the infraglottic area and motor to the intrinsic laryngeal muscles with the exception of the cricothyroid muscle which is innervated by the external laryngeal nerve!!! The superior laryngeal artery (branch of the superior thyroid artery) supplies the vestibule and courses with the INTERNAL LARYNGEAL NERVE. NOT THE SUPERIOR LARNGEAL NERVE! The inferior laryngeal artery comes from the inferior thyroid artery which is a branch of the thyrocervical trunk.

Dr. Manions Nasal Cavity Stuff:

The opening into the nasal cavity in the skull is called the piriform aperture. The two nasal bones and the maxillae form its outline. The superior and middle nasal conchae are part of the ethmoid bone whereas the inferior nasal concha is an independent set of bones within the skull! Inferior to each nasal concha are the corresponding nasal meatuses. The crista galli is located within the skull and is a projection of the ethmoid bone. On both sides of the crista galli, one would find the olfactory bulbs. In general, it can be said that the nasal cavity is found between the orbits and the maxillary sinuses. The olfactory epithelium is located on the superior nasal concha as well as the superior portion of the nasal septum. (NOTE: IF YOU LOSE YOUR SENSE OF SMELL YOU ALSO LOSE YOUR SENSE OF TASTE INTERSTING) The internal opening of the nasal cavity into the nasopharynx is called the internal nasal choanae. (Recall that the external opening was called the piriform aperture) The paranasal sinuses are mucus-lined hollows in the skull. (Frontal, ethmoidal, sphenoidal, and maxillary sinuses) The sphenoidal sinus is unique in that it has its own drainage pathway. (Sphenoethmoidal recess) Some of the ethmoidal sinuses drain into the superior nasal meatus. The rest of the ethmoidal sinuses as well as the frontal and maxillary sinuses drain into the middle nasal meatus. The nasolacrimal duct is the only thing that drains into the inferior nasal meatus.