Nose and Paranasal Sinuses

Question 1

What are the 4 functions of the nose?

Answer 1

1. Respiration
2. Olfaction
3. Reception/ elimination of secretions
4. Speech

Question 2

Identify the external features of the nose

Answer 2

Question 3

Identify the cartilagenous features of the nose and key features of each.

Answer 3

• Lateral cartilage: form the dorsum of the nose
• Alar cartilages: attachment point nasal muscles
  
  • major: antero-superior nostril and apex
  • minor: suspended, forms lateral aspect nostril
• Septal: midline

Question 4

Identify the indicated features of the nasal septum

Answer 4

Question 5

What is the difference about the lining of the vestibule compared to the sections of the nasal cavity?

Question 6

Describe the contents of the nasal mucosa

Answer 6

• Portions are ciliated
• Deep to mucosa are serous and mucous secreting glands
• the mucosa is highly vascularized & capable of engorgement

Question 7

What is the name for this condition?

What are the two major causes?

Answer 7

Deviated septum

trauma or birth injury

Question 8

What are the 3 regions of the nasal cavity?

Answer 8

1. Vestibule
   
   1. lined with skin & vibrissae
2. Respiratory region (inf 2/3)
   
   1. lined with ciliated respiratory mucosa
   2. Mucus secreting goblet cells
   3. warms & moistens air
3. Olfactory region (sup 1/3)
   
   1. lined with olfactory mucosa
   2. olfactory cells with receptors to the olfactory nerve

Question 9

What are the boundaries of the nasal cavity?

Answer 9

• Roof
  
  • nasal bone, frontal bone (w/ frontal sinus) cribiform plate & sphenoid body (w/ sphenoid sinus)
• Floor
  
  • palatine process of maxilla & horizontal plates palatine bone
• Medial Wall
  
  • Nasal septum
• Lateral Wall
  
  • maxilla, lacrimal and nasal bones, ethmoid, inferior nasal concha, perpendicular plate of palatine and anterior of medial plate of petty good process of sphenoid (irregular shape)

Question 10

What is the name of the lateral wall features that create pathways for air to flow within the nasal cavity? How are they shaped? What is the impact of their shape?

What bones form these structures?

Answer 10

Nasal conchae

curved shelves of bone

They slow down the air flow, making it more turbulent and increasing surface area for heat exchange, warming the air before it enters the nasopharynx

• Superior & middle are inferior projections ethmoid bone from late all masses/labyrinth portion
• Inferior nasal concha is an independent bone

Question 11

Identify the features of the lateral Wall

Answer 11

• Nasal Meatus: recess under each conchae’
• Sphenoethmoidal recess: small pocket superior and posterior to superior conchae

Question 12

Identify the openings of the lateral wall. Indicate where they open to.

Answer 12

• Opening of sphenoid sinus: drains onto posterior roof of nasal cavity in sphenoethmoidal recess
• Opening of posterior ethmoidal cells: into superior nasal meatus
• Frontal, maxillary & anterior ethmoidal sunuses open into middle nasal meatus
  
  • marked by semilunar hiatus
• opening of middle ethmoidal cells: on ethmoidal bulla (bulge formed by the sinus)
  
  • superior to semilunar hiatus
• opening of nasolacrimal duct
  
  • connects lacrimal sac on eye to the nose, opening into inferior meatus

Question 13

What are the 4 gateways into the nasal cavity?

Answer 13

• Cribiform plate
  
  • how fibers of CNI exit nasal cavity and enter cranial cavity
  • anterior & posterior ethmoidal canals
    
    • small foramina that allow anterior and posterior ethmoidal nerves/arteries to pass from orbit into cranial cavity
• Sphenopalatine foramen
  
  • formed by process on superior border of palatine bone & inferior surface of sphenoid all body, which form a foramen.
  • allows communication between nasal cavity & pterygopalatine fossa
    
    • sphenopalatine artery and vein & nasal and nasopalatine nerves
• Incisive canal
  
  • Pathway between nasal cavity and incisive fossa of oral cavity
  • nasopalatine nerve from nasal cavity into oral cavity & terminal end of greater palatine artery into nasal cavity and an anastomotic system
• Nares
  
  • internal nasal branches of infraorbital nerve & alar branches of nasal artery loop around the margin of the naris to enter the lateral wall of nasal cavity
• Small foramina
  
  • nasal branches from greater palatine artery pass from palatine canal into nasal cavity through small foramina on lateral wall

Question 14

What are the boundaries of the Pterygopalatine fossa?

Posterior wall?

Anterior wall?

Medial wall?

Roof?

Lateral boundary?

Answer 14

• Posterior wall
  
  • greater wing of pterygoind process of sphenoid bone
• Anterior wall
  
  • body of maxilla
• Medial wall
  
  • perpendicular plate of palatine bone
• Roof
  
  • greater wing sphenoid
  • orbital process of palatine
• Lateral boundary
  
  • entry through pterygomaxillary fissure

Question 15

What are the openings of communication through the Pterygopalatine fossa? What spaces do they communicate with and what are the contents located in each opening?

Answer 15

1. Foramen Rotundum
   
   1. posterosuperiorly with middle cranial fossa
   2. maxillary nerve (V2)
2. Pterygopalatine canal
   
   1. posterosuperiorly with middle cranial fossa; communicates with foramen lacerum
   2. nerve and artery of the pterygoid canal
3. Pharyngeal (palatovaginal) canal
   
   1. Posteroinferiorly with nasopharynx
   2. pharyngeal branches of maxillary nerve & artery
4. Sphenopalatine foramen
   
   1. Medically with nasal cavity
   2. sphenopalatine artery and branches of maxillary nerve
      
      1. innervate posterior part of nasal cavity
5. Inferior orbital fissure
   
   1. anterosuperiorly
   2. infraorbital nerves and artery; zygomatic nerve; inferior ophthalmic vein
6. Pterygomaxillary fissure (body of maxilla not articulating with pterygoid process)
   
   1. laterally with infratemporal fossa
   2. Maxillary artery; posterior superior alveolar nerve and artery
7. Greater palatine canal
   
   1. inferiorly with palate to greater palatine foramen
   2. Descending palatine artery and greater and lesser palatine nerves
8. Lesser palatine canal
   
   1. inferiorly with palate to lesser palatine foramen
   2. lesser palatine nerves and vessels

Question 16

Identify the nerves within the Pterygopalatine Fossa

Identify where they enter and exit

Answer 16

• Maxillary nerve:
  
  • enters: foramen rotundum
  • infraorbital (continuation maxillary):
    
    • exit: inferior orbital fissure
  • zygomatic
    
    • exit: inferior orbital fissure
  • nasal:
    
    • exit: sphenopalatine foramen **largest
  • posterior superior alveolar
    
    • exit: pterygomaxillary fissure
  • pharyngeal
    
    • exit: pharyngeal canal
  • palatine
    
    • exit: palatine canal
• Pterygopalatine ganglion
  
  • parasympathetic ganglion
  • preganglionic parasympathetic fibers from CNVII
  • greater pterosal (parasympathetic) joins with deep petrosal nerve (posts-ganglion is sympathetic) to form nerve of pterygoid canal
  • posty synaptic fibers distribute with branches of maxillary nerve

Question 17

Identify the vascular use of the pterygopalatine fossa, specifically the 6 terminal branches of the maxillary artery.

What structures do these branches supply?

Answer 17

1. Posterior superior alveolar artery
   
   1. upper molars and premolars
2. infraorbital artery
   
   1. exits via inferior orbital fissure, emerges through infraorbital foramen
3. artery of the pterygoid canal
   
   1. through pterygoid canal
4. pharyneal branch of maxillary artery
   
   1. through pharyngeal canal
5. descendign palatine artery
   
   1. enters palatine canal and divides into
      
      1. lesser palatine artery: lesser palatine canal
      2. greater palatine artery: greater palatine canal
6. sphenopalatine artery
   
   1. terminal branch maxillary
   2. travels with nasopalatine nerve

Question 18

In addition to providing blood supply, what is the function of the abundant vasculature supplied to the nasal cavity?

Answer 18

Warms and humidifies inhaled air

allows nasal mucosa to swell and shrink

Question 19

Describe the arterial branches that supply the nasal cavity and their origins. How do they enter the cavity? The

Answer 19

• Internal Carotid
  
  • opthalmic artery
    
    • anterior ethmoidal
      
      • lateral and septal branches
      • anterior and middle ethmoidal cells; anterior part lateral wall; anterior nasal septum
    • posterior ethmoidal arteries
      
      • lateral and septal branches
        
        • posterior ethmoidal cells; superior conchae; superior nasal septum
  • access through cribiform plate
  • anterosuperior region of the cavity
• External Carotid
  
  • maxillary
    
    • sphenopalatine
      
      • lateral wall of nasal cavity through sphenopalatine foramen
      • travels with nasopalatine nerve
      • major artery to nasal cavity mucosa
      • lateral (middle and inferior conchae) and septal branches (posterior septum)
    • greater palatine
      
      • enters through greater palatine foramen, enters incisive canal
      • Anastomoses with sphenopalatine artery
      • septum and floor of nasal cavity
  • enter from pterygopalatine fossa
  • posteroinferior regions

Question 20

What is the name of the area where all the arteries that supply the septum anastomoses?

What 5 arteries anastomoses here?

Answer 20

Kiesselbach Area

anterior and posterior ethmoidal arteries

greater palatine

sphenopalatine

septal branch superior labial

Question 21

What is epistaxis?

Where are the most common sites?

Answer 21

Nosebleeds

most comon from kiesselbach area

less frequently, posterior epitaxis occurs from a bleed of the SPA or branch of SPA = profound bleeding

Question 22

Where does nasal cavity venous drainage occur?

Why is this considered a danger area of the face?

Answer 22

Submucosal venous plexus

drains to sphenopalatine, facial and ophthalmic veins

posterior tributaries to cavernous sinus or pterygoid plexus

anterior tributaries to facial vein (IJV)

it is considered a danger area b/c communication with deep venous sinuses, so infections have the potential to become intracranial infections

Question 23

Where do anterior regions of nasal cavity lymphatic drain?

Posterior regions?

Answer 23

• Anterior
  
  • Pass around margins of nares, connect with submandibular lymph node
• posterior
  
  • Upper deep cervical nodes
  • some though retropharyngeal nodes

Question 24

What is the name for loss of smell and how does it commonly occur?

What other sense can this impact?

Answer 24

Anosmia

commonly arrises from nasal infections or ethmoidal fractures

bilatera anosmia can include a loss of taste

Question 25

Describe the general sensory innervation supplied to the nose.

Answer 25

* Anterosuperior nasal mucosa (septum & lateral wall) * Anterior ethmoidal * internal (anterosuperior nasal cavity) * external (nasal tip) * posterior ethmoidal * posterosuperior nasals cavity * posteroinferior nasal mucosa on septum * nasopalatine nerve (CNV2) to nasal septum * Enters through pterygopalatine ganglion via sphenopalatine foramen & enters incisive canal * primary supplier * posterior superior medial nasal nerve * from maxillary * enters from pterygopalatine ganglion via sphenopalatine foramen * supplies medial wall * Posteroinferior of nasal mucosa on lateral wall * Posterior inferior lateral nasal nerve * branch of greater palatine nerve (from CNV2) * posterior superior lateral nasal nerve * from maxillary (CNV2) * enters from pterygopalatine ganglion via sphenopalatine foramen * External nose * infrtrochlear (CNV1) * and infraorbital (CNV2)

Question 26

Gland in the nasal mucosa are innervated by parasympathetic fibers from what nerve? Describe this pathway

Answer 26

CN VII Parasympathetic preganglionic motor fibers leave the geniculate ganglionof the facial nerve as the greater petrosal nerve, pass through the pterygoid canal, enter the pterygopalatine fossa and synapse in the pterygopalatine ganglion post ganglion is parasympathetic fibers exit by using nasal nerves (CNV2) to reach the glands

Question 27

What is the name for the formation of air cells or sinuses? Why are these formed? What is their relationship to the nasal cavity? What is unique about the mucosa lining these spaces?

Answer 27

Pneumatization they develop graduall over the course of cranial growth, and they are air-filled extension of the respiratory part of the nasal cavity that reduces the bony mass of facial skeleton The communicate with the nasal cavity through bony openings (Ostia)

Question 28

Identify the indicated paranasal sinuses. For each sinus describe its: location drainage innervation arterial supply

Answer 28

* Frontal Sinus * Position * posterior to superciliary arches, superior to nasal cavity * right and left typically asymmetrical and separated by septum * Drainage * drain through frontonasal duct into the ethmoid infundibulum (opens to semilunar hiatus in middle meatus) * Innervation * supraorbital nerve (CNV1) * Arterial supply * supraorbital and supratrochlear arteries (ophthalmic) * Maxillary * position * body of maxillae, lateral to nasal cavities * roof = floor orbit; floor = alveolar part maxilla * drainage * Maxillary Ostia, opens into semilunar hiatus of middle meatus * Most commonly infected paranasal sinus b/c difficult drainage * innervation * superior alveolar nerves (CNV2) * arterial supply * superior alveolar branchesof maxillary artery, floor by descending and greater palatine arteries * Sphenoidal Sinuses * position * body of sphenoid * at age 2 posterior ethmoidal cells invade sphenoid, forming phenoidal sinuses * unevenly divided by bony septum * drainage * open to spnehoethmoidal recess * innervation * posterior ethmoidal nerve * arterial supply * posterior ethmoidal artery * Ethmoidal Cells (sinuses) * position * series air cells within latera masses ethmoid bone (fully grown at 12 yrs) * sever infection can break through medial wall of orbit * anatomiccaly divided into anterior, idle and posterior groups * drainage * anterior: semilunar hiatus of middle meatus * middle: directly into middle meatus = ethmoidal bulla * posterior: directly into superior meatus * innervation * anterior and posterior ethmoidal nerves * arterial supply * anterior and posterior ethmoidal arteries

Question 29

How do paranasal sinuses become infected? What are the symptoms? What complications can arise

Answer 29

B/c sinuses are continuous with nasal cavities, infection may spread from nasal cavity to sinus inflammation and swelling of mucosa of the sinuses and nasal cavity (rhinosinusitis); this may obstruct the openings, blockgin the flow of secretions, causing microorganisms to get trapped and leading to secondary inflammation