Term
| where the auditory (Eustachian) tube opens. What structure surrounds this opening? |
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Definition
| It opens into the lateral wall of the nasopharynx just posterior to the nasal cavity. What structure surrounds this opening? The torus tubarius is a cartilage tube-like structure that creates a rounded elevation around the opening that helps maintain patency of the auditory tube. |
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Term
| Where the sinuses surrounding the nasal cavities are located and where they drain. |
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Definition
| Frontal sinuses are found in the frontal bone anteriorly – drain through frontonasal duct to the middle meatus at the anterior hiatus semilunaris. Ethmoid sinuses in the ethmoid bulla and upper lateral nasal area – they 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 – drain to the space above the superior conchae (sphenoethmoidal recess). Maxillary sinus in each maxillary bone lateral to the nasal cavity – drain to the middle meatus at the posterior hiatus semilunaris. |
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Term
| How the maxillary sinus is different? |
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Definition
| 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. |
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Term
| What other major structures are related to the maxillary sinus? |
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Definition
| 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. |
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Term
| What nerves innervate the walls of the nasal cavity? |
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Definition
| The maxillary division of the trigeminal nerve (CN 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. |
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Term
| What nerves stimulate mucous secretion in the nasal cavity? |
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Definition
| Parasympathetic fibers stimulate the numerous mucous glands in the nasal cavity to secrete. These fibers come from the facial nerve (CN 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. |
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Term
| Where the blood supply to the nasal cavity originates? |
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Definition
| The blood supply of the septal and lateral walls of the nasal cavity comes from branches of the sphenopalatine artery that is a continuation of the maxillary artery. The blood vessels enter the posterior area of the nasal cavity and spread anteriorly. |
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Term
| What muscles are associated with the soft palate and what they do? |
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Definition
| The primary muscles associated with the soft palate are the levator veli palatini and the tensor veli palatini. Their function is what their name indicates, i.e., the levator veli palatini elevates the soft palate or increases its curvature while the tensor palatine tenses the palate and flattens it. The palatopharyngeus helps tense the palate and pulls up on the walls of the pharynx effectively narrowing the opening between the oropharynx and nasopharynx. |
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Term
| What are the three areas of the pharynx? |
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Definition
| nasopharynx, oropharynx, and laryngopharynx. |
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Term
| What is the function of the pharyngeal constrictors? |
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Definition
| The pharyngeal constrictors (superior, middle, and inferior) contract involuntarily in a superior to inferior pattern such that the sequential constriction helps propel food into the opening of the esophagus. |
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Term
| What innervates the wall of the pharynx? |
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Definition
| A plexus of nerves called the pharyngeal plexus is formed by fibers from pharyngeal branches of the vagus (CN X) and contributions from the spinal accessory (CN XI) nerves. These include motor fibers to muscles of the wall of the pharynx (and sensory fibers from the vagus). |
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Term
| Where the major tonsilar structures are located? |
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Definition
| The major lymphoid accumulations are arranged in a ring-like manner around the openings of the naso- and oropharynx into the alimentary tract. The pharyngeal tonsils (adenoids if inflamed) are located adjacent Eustachian tube openings on the lateral wall of the nasopharynx while the palatine tonsils are located on the lateral walls of the oropharynx and the lingual tonsils are found on the posterior surface of the tongue. |
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Term
| What two bones are primarily responsible for side-to-side movement of the skull, nodding of the head? |
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Definition
| Side to side movement is due to the articulation of the atlas and axis. Nodding (flexion-extension) is due to the articulation of the occipital bone of the skull with the atlas. |
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Term
| What the alar (check) ligament does? |
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Definition
| The alar ligament connects the dens with the occipital bone and limits rotation of the skull on the vertebral column. |
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Term
| What the dens (odontoid process) does and what holds it in place? |
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Definition
| The dens is the modified vertebral body of the atlas that became attached to the axis. It forms the point of rotation of the atlas on the axis. It is held in place against the anterior arch of the atlas by the transverse fibers of the cruciate ligament. |
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Term
| What the space is between the cervical vertebral bodies and the posterior pharyngeal wall, and its clinical significance? |
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Definition
| The retropharyngeal space lies between the prevertebral and buccopharyngeal fascias of the neck. It is a potential route for spread of infection from the deep neck structures into the superior mediastinum. |
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