A3 - nose and palate Flashcards
what does the nose consist of?
external nose and nasal cavity
what is the nose responsible for?
- olfaction
- respiration
- filtration of dust
- humidification of inspired air
- reception and elimination of secretions (from nasal mucosa, paranasal sinuses and nasolacrimal ducts)
what are the choanae?
- 2 posterior nasal apertures, separated by the vomer
- the opening between the nasal cavity and the nasopharynx
what is the external nose mainly formed from?
cartilage
where does the dorsum of the nose extend from and to?
from the root of the nose to the apex (tip)
what are the nares (nostrils) bound laterally by?
the alae (wings) of the nose
what does the thicker skin over the cartilages of the nose contain?
many sebaceous glands
the skin extends into the vestibule of the nose, where it has a variable number of ______ ?
vibrissae
what does the bony part of the nose consist of?
- nasal bones
- frontal processes of maxillae
- nasal part of frontal bone
- bone part of septum (ethmoid and vomer bones)
what is the cartilaginous part of the nose formed from?
- septal cartilage
- a pair of lateral cartilage
- a pair of alar cartilages
what are the muscles of the nose all innervated by?
facial nerve (CNVII)
name 3 muscles of the nose
- procerus muscle (originates in the fascia overlying the nasal bone and lateral nasal cartilage, inserting into the inferior forehead. contraction can depress the medial eyebrows, and wrinkles the skin of the superior dorsum)
- nasalis muscle
- depressor septi nasi
what is sensory innervation of the external nose derived from?
trigeminal nerve (CNV)
the _______ nerve, a branch of the ______ nerve, supplies the skin of the dorsum of the nose, nasal alae and nasal vestibule
the EXTERNAL NASAL nerve, a branch of the OPHTHALMIC nerve, supplies the skin of the dorsum of the nose, nasal alae, and nasal vestibule
what are A and B?
A = ethmoid (perpendicular plate)
B = vomer
what 4 bones can be seen forming the roof of the nose?
- nasal
- frontal
- ethmoid
- sphenoid
what 2 bones form the floor of the nose?
- maxilla (palatine process)
- palatine (horizontal process)
what are A, B and C?
A = inferior nasal concha
B = ethmoid (middle nasal concha)
C = inferior meatus
where does the nasolacrimal duct drain?
inferior meatus
what is the most superior part of the resp tract?
nasal cavity
what are the 3 divisions of the nasal cavity?
- vestibule — the area surrounding the anterior external opening to the nasal cavity
- respiratory region — lined by a ciliated pseudostratified epithelium, interspersed with mucus-secreting goblet cells
- olfactory region — located at the apex of the nasal cavity, lined by olfactory cells with olfactory receptors
what 4 pathways do conchae create for air flow?
inferior/middle/superior meatus and sphenoid-ethmoidal recess
conchae functions
- increase SA of nasal cavity — increases teh amount of inspired air that can come into contact with the cavity walls
- make the air flow turbulent — air spends longer in nasal cavity, so that it can be humidified
what 9 bones contribute to the nasal cavity?
- ethmoid
- sphenoid
- nasal
- maxilla
- frontal
- vomer
- inferior nasal conchae
- palatine
- lacrimal
nerve for olfaction?
olfactory nerve (CNI)
nerve for general sensation?
trigeminal nerve (CNV)
nerve for serous glands?
- PS fibres of facial nerve (CNVII)
- S - T1 of spinal cord — intended for regulation of blood flow though mucosa
what are B and C?
B = hiatus semilunaris
C = infundibulum
what are paranasal sinuses?
= hollowed out air spaces located within the sphenoid, ethmoid, maxillary and frontal bones
what are paranasal sinuses lined with?
pseudostratified columnar epithelium
what is the function of paranasal sinuses?
lighten the weight of the skull
what are the 4 paranasal sinuses?
where does the sphenoid sinus drain?
sphenoethmoidal recess
what drains into the middle meatus?
frontal, maxillary, and anterior ethmoidal sinuses
where does the posterior ethmoidal drain?
superior meatus
why is the maxillary sinus most prone to infection?
it has its optimum high up near the roof — therefore in the upright position the sinus only drains when full
what can be used to access the pituitary gland?
sphenoid sinus
where does the nasolacrimal duct drain?
inferior meatus
what are A and B?
A = maxillary sinus
B = ethmoid air cells
where do the frontal and maxillary sinuses drain into the middle meatus?
- frontal — infundibulum
- maxillary — posterior end of hiatus semilunaris
what are A and B?
A = frontal
B = sphenoid
what does the palate form and consist of?
- the roof of the mouth and the floor of the nose
- consists of hard palate anteriorly and the soft palate posteriorly
what kind of epithelium is the hard palate covered in?
keratinised stratified squamous epithelium
what nerve provides sensory innervation to much of the hard palate?
greater palatine nerve
what is the skeleton of the hard palate formed from?
the palatine process of the maxilla and the horizontal process of the palatine bone
what nerve passes through the incisive foramen and what does it do?
nasopalatine nerve — assists in innervating the anterior aspect of the hard palate
what goes through the greater and lesser palatine foramen?
greater — greater palatine nerve and artery
lesser — lesser palatine nerve and artery
what 5 muscles make up the soft palate?
1) tensor veil palatini muscle
2) levator veil palatini muscle
3) musculus uvulae
4) palatopharyngeus muscle (also considered a pharyngeal muscle)
5) palatoglossus muscle (also considered an extrinsic muscle of the tongue)
- the soft palate is formed by a series of muscles surrounded by a mucosal membrane
- these muscles alter the shape of the soft palate and during swallowing, closing off the airway
innervation of the soft palate muscles?
the muscles of the soft palate are innervated by the pharyngeal plexus of the vagus nerve (CN X), except for the tensor veli palatini muscle, which is innervated by the mandibular branch of the trigeminal nerve (CN V3)
what nerve supplies sensory info to the nose and palate and motor innervation to tensor veli palatini?
trigeminal
what muscle elevates the soft palate in swallowing and speech?
levator veli palatine
sensory innervation to the angle of the mandible?
cervical plexus — NOT mandibular division of trigeminal nerve
what is the greater palatine nerve a branch of?
maxillary division of CN V (V2)
where is olfactory mucosa located?
above the superior nasal concha
The olfactory neurones pass through the cribriform plate and synapse with second order neurones in the what?
olfactory bulb
A common site for nose bleed (epistaxis) is the lower anterior part of the septum. This is a site rich in capillaries where all the five vessels supplying the nasal septum anatomose. What is the name of this vascular plexus?
Kiesselbach’s plexus
Which division of the trigeminal nerve supplies the postero-inferior part of the nose?
maxillary
Which division of the trigeminal nerve supplies the antero-superior part of the nose?
ophthalmic
Which cranial nerve provides parasympathetic innervation to the nasal glands?
facial
Which sinus may be damaged during dental surgery for tooth extraction?
maxillary
Which structure drains into the inferior meatus?
nasolacrimal duct
