Lecture 6: Nasal And Oral Cavities Flashcards
Laryngopharynx is continuous with what?
Oesophagus
Nasopharynx
Superior to soft palate
• Inferior to sphenoid bone
• Passage for air only.
• Contains opening of pharyngotympanic tube.
Pharyngeal tonsils
• = Adenoids.
• Trap and destroy pathogens entering nasopharynx in air.
If enlarged may cause difficulty in breathing
Pharyngotympanic tube
Communication between nasopharynx and tympanic cavity.
Function is to equalise air when your ears are blocked
What is pharyngeal isthmus and what does it do
Pharyngeal isthmus closes during swallowing to prevent food entering nasal cavity.
Palatine tonsils
Between palatoglossal and palatopharyngeal arches.
Oral cavity
- Oral vestibule: space between teeth & cheeks
* Oral cavity proper: space between upper & lower dental arches
Trigeminal nerve: cutaneous distribution
Tip of nose = CN V1
Ala of nose = CN V2
Upper lip = CN V2
Lower lip = CN V3
Innervation of gingivae & teeth via trigeminal nerve
Maxillary nerve : superior alveoli nerve cnv2
Mandibular nerve: inferior alveoli nerve cnv3
Teeth
Deciduous = 20 teeth Permanent = 32 teeth
Blood supply of dental arch
Maxillary (upper) dental arch supplied by superior alveolar artery.
Mandibular (lower) dentral arch supplied by inferior alveolar artery.
Both arteries branch from maxillary artery.
Muscles of soft palate, Innervation and blood supply
5 muscles of soft palate: • Tensor veli palatini • Levator veli palatini • Palatoglossus • Palatopharyngeus • Musculus uvulae All but tensor veli palatini have motor Innervation by vagus. Tensor veli palatini has motor Innervation via mandibular nerve cnv3. All 5 muscles have sensory Innervation via glossopharyngeal nerve. Blood supply via greater palatine ( from maxillary artery) Venous drainage: pterygoid venous plexus
Tongue
- Filiform papillae => rough
- Fungiform & circumvallate papillae => house taste buds
- No papillae in posterior 1/3 of tongue, only tonsil.
Taste sensation
- “Taste” = chemical sense.
- Saliva dissolves food, trickles into open pore of taste bud.
- Taste cells send signal to CNS via CN VII/IX or X depending on region of tongue. Vagus, glossopharyngeal, facial
- Taste buds only last 10 days and have to be replaced.
Tongue movement
- Extrinsic muscles alter POSITION of tongue
- Intrinsic muscles alter SHAPE of tongue
AMotor innervation: hypoglossal nerve (CN XII)
Extrinsic tongue muscles: innervation
Motor innervation to:
- Styloglossus from stylish process
- Hyoglossus from hyoid bone
- Genioglossus from geniculate bodies
Blood supply of the tongue
External carotid artery splits into sublingual and deep lingual
Innervation of the tongue
General sensory: lingual nerve ( mandibular nerve)
Special sensory: chorda tympani
Motor to all muscles except palatoglossus : hypoglossal
Palatoglossus: vagus
Tongue Innervation
General sensory- lingual (mandibular branch of trigeminal)
Special sensory- chorda tympani (facial) anterior 2/3
Special/ general - glossopharyngeal posterior 1/3
Motor - hypoglossal
* Styloglossus
*Genioglossus
*Hyoglossus
Motor- vagus
palatoglossus
Styloglossus
From styloid process
Hyoglossus
From hyoid bone
Genioglossus
From mandible
Gag reflex
Afferent limb: glossopharyngeal (sensory to posterior 1/3 )
Efferent limb: vagus ( motor to palatoglossus)
Innervation of nasal cavity
General sensory
Special sensory
General sensory-
Anterosuperior: opthalamic
Posterosuperior: maxillary
Special sensory: olfactory
Paranasal sinus
Most drain into middle nasal meatus
Except sphenoid sinus which drains into sphenoethmoidal recess
Paranasal sinus Innervation
Frontal sinus- supra orbital nerve ( opthalmic)
Maxillary sinus- infra orbital nerve ( maxillary )
Rhinosinusitis
Inflammation of para nasal sinus ( usually ethmoid or maxillary)
Caused by obstruction of normal discharge secretion
Causes pain, fever, headaches
