Zill - Nasal Cavity Flashcards
Main functions of nasal cavity?
Modify Air (warm, humidfy, filter)
Sense Smell
Directional outcome of nasal cartilage?
Opens inferiorly toward mouth = you smell what you eat
What benefit does the shape of the nasal conchae (turbinates) offer?
Increase surface area
Boundaries of nasal cavity?
Floor = Maxillary Bone, Palatine Bone
Roof = Nasal Bone, Frontal Bone, Ethmoid, Sphenoid
Lateral Wall = Nasal Bone, Maxillary, Inferior Concha, Palatine, Ethmoid, Sphenoid
Clinical: Fracture of Nose?
Break Cribiform Plate, Floor of Ant. Cranial Fossa
CSF can leak from Nose
Can result in Meningitis
What is unique about the Inferior Concha?
It’s a separate bone
The Superior/Middle are on the Ethmoid
Clinical: What areas are susceptible to sinus infections in the head?
Maxillary Sinus - Hiatus Semilunaris
Frontal Sinus - Infundibulum
**Nerves of Nasal Cavity**
Chemical?
General Sensation?
Muscous Glands?
Chemical - CN I (Olfactory N.)
General Sensation (Somatic Sensory) - V1 + V2
V1 Anterior Ethmoidal, V2 Nasal Branches, V2 Nasopalatine
Mucous Glands (Visceral Motor Parasympathetics) - CN VII (Facial N., by Pterygopalatine Ganglion)
Clinical: What can be unique about the nature of nosebleeds?
Can be extensive due to Anastomoses, spurt if arterial
Major branch = Sphenopalatine Artery (From maxillary)
Other branches from Ophthalmic, Facial
Clinical: Sinus Infection of Ethmoid?
if blocked, infection can spread to Orbit
Clinical: Complications to sinus from dental work?
Roots of maxillary teeth are in floor of Maxillary Sinus; this structure can be damaged by tooth extraction
Clinical: Infected sinus referred pain?
V2 - Ant. and Post. Sup. Alveolar N. supplies Maxillary Sinus & teeth
An infected sinus can feel like tooth ache
- - -
Test by pressing on maxillary sinus
Palate Development
Primary vs Secondary
Primary - Anterior to incisive foramen, formed by union of Medial Nasal Processes
Secondary - Posterior to incisive foramen, formed by fusion of Maxillary Processes
Clinical: Posterior Cleft Palate
Failure of fusion of Secondary Palate
(failure of Maxillary Processes to fuse on each side)
Clinical: Anterior Cleft Palate (Cleft Lip)
Failure of fusion of Medial Nasal Process and Maxillary Process
“Cleft Lip”
Muscle: Tensor Palati
Action:
Muscle: Tensor Palati
Action: Tenses Soft Palate
Muscle: Levator Palati
Action:
Muscle: Levator Palati
Action:Elevates Soft Palate
Clinical: How is pressure equilibriated in Tympanic Membrane?
Contraction of Tensor and Levator Palati when swalling opens Auditory Tube (common origin)
Ears “pop”
Muscle: Palatoglossues
Action:
Inn:
Muscle: Palatoglossues
Action: Draws Palate down
Inn: CN X (Vagus)
*Important for chewing*
Innervation of Palate?
Blood Supply?
All from V2 (Somatic Sensory)
Greater Palatine N. and Nasopalatine N. to Hard Palate
Lesser Palatine N. to Soft Palate
Descending Palatine A. (From Maxillary)
Sphenopalatine
Ascending Palatine
Muscle: Stylopharngeus
Action:
Inn:
Muscle: Stylopharngeus
Action: Raise Pharynx, Pull Wall Laterally
Inn: CN IX (Branchiomotor)
Mechanism of Swallowing: Voluntary and Involuntary?
Voluntary: Initates
- Form bolus, palate down by Palatoglossus
- Push bolus back, contract by Mylohyoid, Styloglossus
Involuntary:
- Elevate soft palate by Tensory, Levator, Stylopharyngeus
- Down Tube, contract Pharyngeal Contrictors
Clinical: Talking during swallowing?
Food can enter Nasopharynx and Nasal Cavity,
Clinical: Tonsillitis
Inflammation of Palatine tonsils, often removed via surgery
Clinical: Complications during tonsillectomy?
Glossopharyngeal Nerve (CN IX) damage
Bleeding from Tonsillar branch of Facial Artery
