Retropharynx, Pharynx and Nasal Cavity Flashcards
Where do the auditory (Eustachian) tubes open?
It opens into the lateral wall of the nasopharynx just posterior to the nasal cavity
What structures surround the auditory (Eustachian) tube opening?
The torus tubers is a cartilage tube-like structure that creates a rounded elevation around the opening that helps maintain potency of the auditory tube
Where are the sinuses surrounding the nasal cavities located and where do they drain?
Frontal sinuses are found in the frontal bone anteriorly and drain through frontonasal duct to the middle meatus at the anterior hiatus semilunairs.
Ethmoid sinuses in the ethmoid bulla and upper lateral nasal area and drain through numerous small openings into the middle meatus and some posterior ones into the superior meatus.
Sphenoid sinuses are in the body of the sphenoid bone posterior superior to the nasal cavity and drain to the space above the super conchae (sphenoethmoidal recess).
Maxillary sinus in each maxillary bone lateral to the nasal cavity and drain to the middle meatus at the posterior hiatus semilunaris
How is the maxillary sinus different?
The opening of the maxillary sinus is in the superior aspect of the sinus, therefore mucus must be directed upward by the ciliated epithelium to the opening. It is difficult to drain when the sinus is filled and the individual is upright. In addition roots of the teeth form conical elevations that protrude into the floor of the sinus, thus infections at the roots of the teeth can penetrate into the sinus cause complications
What other major structures are related to the maxillary sinus?
The orbit is separated from the sinus by a thin sheet of bone. The close proximity of teeth to the floor of the sinus is also important.
What nerves innervate the walls of the nasal cavity?
The maxillary division of the trigeminal nerve (V2) provides branches to the mucosa through nasal branches and the nasopalatine nerve that supplies the nasal septum. The upper portion of the nasal cavity is supplied by olfactory nerves that penetrate the cribriform plate from the olfactory bulbs.
What nerves stimulate muscous secretion in the nasal cavity?
Parasympathetic fibers stimulate the numerous mucous glands in the nasal cavity to secrete. These fibers come from the facial nerve (VII) through its greater petrosal branch as preganglionic fibers. The fibers synapse in the pterygopalatine ganglion, which is attached to maxillary nerve in the pterygopalatine fossa. The postganglionic parasympathetic fibers travel with regular branches of the maxillary to the nasal mucosa and with the greater and lesser palatine nerves to the surface of the hard and soft palates.
