Nasal Cavity And Oral Cavity Flashcards
Describe the boundaries of the nasal cavity.
Roof
Anterior part:
1. Nasal cartilage
2. Nasal bone
3. Frontal bone
Middle part: cribriform plate of ethmoid
Posterior part: body of sphenoid and sphenoid air sinus
Floor: hard palate( maxilla + palatine bone)
Medial wall- nasal septum
1. Anterior part- spetal cartilage
2. Posterior part - vomer
3. Upper part - perpendicular plate of ethmoid.
Lateral wall:
• 3 nasal conchae (elevations)
- superior
-middle
-inferior
Superior and middle conchae are processes of the ethmoid bone, inferior concha is a separate bone
• 3 meati (spaces)
- superior
-middle: contains bulla ethmoidalis(swelling), hiatus semilunaris(groove) and infundibulum
-inferior
• sphenoethmoidal Recess - space between superior concha and sphenoid.
State the various openings of the nasal cavity
** Lateral wall:**- nasal sinuses and lacrimal duct
1. Sphenoethmoidal Recess - contains opening of sphenoethmoidal air sinus
2. Superior meatus- posterior ethmoidal sinus
Middle meatus:
3. Bulla- middle ethmoidal sinus
4. Hiatus semilunaris (anterior part)- anterior ethmoidal sinus
5. Hiatus semilunaris (posterior)- maxillary air sinus
6. Infundibulum - frontal air sinus
Inferior meatus- nasal lacrimal duct
Describe the Nerve supply of the nasal cavity
Skin of the nose:
1. Infra trochlear nerve- branch of nasociliary Nerve which is a branch of opthalmic Nerve
2. External nasal nerve- nasociliary; opthalmic Nerve
3. Infraorbital nerve- from maxillary
Nasal septum:
1. Upper part- olfactory nerves
2. Anterior part- anterior ethmoidal nerve (from nasociliary)
Posterior part- nasopalatine nerve(maxillary) ; carry secretory fibres to nasal glands
** Lateral wall**
Upper part- olfactory nerves
* Anterior part*- anterior ethmoidal(nasociliary)
Posterior part- nasal branches of the greater palatine nerve and sphenopalatine ganglion; carry secretory fibres to nasal glandsg
Describe the arterial supply of the nasal cavity
2 from ophthalmic artery:
1. Anterior ethmoida
2. Posterior ethmoidal
Septum:
2 from maxillary artery:
1. Sphenopalatine - main supply
2. Greater palatine
2 from the facial artery:
1. Lateral nasal (skin)
2. Septal branch of superior labial artery
Lateral wall:
1. Anterosuperior quadrant - anterior ethmoidal
2. Antero-inferior quadrant - branches of facial and greater palatine arteries
3. Posterosuperior- sphenopalatine artery
4. Posteroinferior- branches of greater palatine, which pierces perpendicular plate of palatine.
State the Clinical correlation of the nose
** Little’s Area of Epistaxis**
•Area of anastomosis between 3 arteries: anterior ethmoidal, sphenopalatine and septal branch of superior labial ( kiesselbach’s plexus)
•Site: antero-inferior part of nasal septum
• commonest site of Epistaxis (nose bleeding)
Describe the Venous drainage of nasal cavity
• Veins form a plexus beneath the mucosa and in general, accompany the arteries.
• Veins drain into facial vein, pterygoid Venous plexus and pharyngeal Venous plexus.
NB
* -There submucous plexus is more marked in the region of little’s area.
- retrocolumellar vein runs vertically downwards, crosses floor of nasal cavity to join the Venous plexus in the lateral wall. (Common bleeding site in young individuals)
State the functions of the paranasal air sinuses
- Decrease the weight of the skull
- Make the voice resonant
- Increase surface area for the air
- Air conditioning for the head by adding humidity and temperature to Inspired air.
- Absorb shocks in case of facial trauma.
- Aid in growth of facial skeleton after birth.
Identify the clinical correlation of Paranasal air sinuses.
- Sinusitis - infection of Paranasal air sinus, presents as headache and persistent thick purulent discharge from the nose.
- Frontal sinusitis - infection may spread posteriorly into the anterior cranial fossa causing frontal lobe abscess, subdural abscess or meningitis or downwards into the orbit leading to orbital cellulitis. Pain is severe and localised over the affected sinus.
- Ethmoidal sinusitis- associated with infection of other sinuses
- Sphenoidal sinusitis- isolated is rare. It is usually part of pansinusitis or is associated with infection of posterior ethmoidal sinuses
* Infection of sphenoidal air sinuses spreading upwards may affect pituitary gland and optic chiasma* - Maxillary sinusitis - maxillary sinus is most commonly infected due to the following reasons:
• infection can Reach into the sinus form infected nose (viral rhinitis), carious upper premolar and molar teeth and infected frontal and anterior ethmoidal sinuses.
• acts as a secondary reservoir for pus from frontal air sinus through frontonasal duct and hiatus semilunaris.
• pain of maxillary sinusitis is referred to the upper teeth and infraorbital skin due to common innervation by maxillary nerve - Drainage of maxillary sinus- opening is located in upper part of lateral wall of nose which is disadvantagous site for adequate natural drainage
Drained surgically by antral puncture or fenestration of the antrum - Carcinoma of maxillary sinus- arises from the mucous lining of the sinus
Describe the relations of the palatine tonsils.
Site: tonsillar fossa
Boundaries:
Anterior- palatoglossal arch containing palatoglossus muscle
Posterior - palatopharyngeal arch containing palatopharyngeus muscle.
Apex - soft palate, where both arches meet.
Base: dorsal surface of posterior third of the tongue.
Lateral wall(tonsillar bed)- superior constrictor muscle.
Tonsillar bed:
• formed from within outwards by;
(a) Pharyngobasilar fascia
(b) Superior constrictor muscle
( c) Buccopharyngeal fascia
Outline the blood supply of the palatine tonsils.
- Facial artery: tonsillar branch- main supply
- Facial artery: ascending palatine branch
- Ascending pharyngeal: from ECA
- Lingual artery: through dorsal lingual arteries
- Lesser palatine: from greater palatine artery
Describe the lymphatic drainage of the tongue and paranasal sinuses.
Tongue
Tip: by apical vessels into submental-submandibular- upper deep cervical
Anterior 2/3: submandibular
- central part: bilateral by central vessels
- peripheral part: unilateral by marginal vessels
Posterior 1/3: by basal vessels into upper deep cervical (jugulodigastric) lymph nodes and retropharyngeal .
Tonsil: upper deep cervical LN
Paranasal sinuses:
Frontal- submandibular
Ethmoidal- submandibular and retropharyngeal
sphenoidal- retropharyngeal
maxillary- submandibular
State the locations of the taste buds and name the lingual papillae
Taste receptors: taste buds in the tongue, epiglottis, soft palate and oropharynx.
Lingual papillae: fungiform, circumvallate and foliate papillae
Outline the origin, functional components, branches, distribution and pathways related to the maxillary nerve.
Origin: Trigeminal ganglion
Course:
Lateral wall of cavernous sinus- Foramen rotundum- Pterygopalatine fossa- Pterygomaxillary fissure- Infra temporal fossa- infra orbital fissure- infra orbital groove- infra orbital canal- infra orbital foramen( divides into 3 branches)
Branches and distribution:
~in cranial cavity
1. Meningeal branch- to dura
~in Pterygopalatine fossa
2. Ganglionic branches- sensory fibers to sphenopalatine ganglion and parasympathetic fibers from sphenopalatine ganglion to lacrimal gland.
3. Zygomatic nerve- enters inferior orbital fissure and divides into zygomaticofacial and zygomaticotemporal
4. Posterior superior alveolar nerve- upper molar teeth
5. Middle superior alveolar nerve- upper premolar
6. Anterior superior alveolar- canine and incisor teeth
7. 3 terminal branches- palpebral, nasal and labial
Outline the branches of the third part of the maxillary artery.
State the unique features of the lingual mucosa
