HNNS Anatomy - Nasal cavity and Paranasal air sinuses

Question 1

5 functions of the nasal cavities.

Answer 1

Respiration 
Olfaction 
Filtration of dust 
Humidification of air 
Drainage of paranasal air sinuses

Question 2

Define the upper and lower respiratory tracts.

Answer 2

Upper = nasal cavities 
Lower = Larynx, trachea, bronchi, bronchioles, alveoli

Question 3

Bones that form the nose?

Answer 3

Nasal bones
Frontal process of maxillae
Nasal part of frontal bone

Question 4

Bones that form the roof, septum and floor of the nasal cavity?

Answer 4

Roof = Frontonasal, Ethmoid and Sphenoid bones
Septum= Perpendicular plate of ethmoid bone, Vomer, Septal cartilage 
Floor = Hard palate: Palatine process of maxilla, horizontal plate of palatine bone

Question 5

Structure of the lateral walls of the nasal cavities?

Answer 5

3 curvature plates = concha/ turbinates with Meatus* underneath for drainage of paranasal sinuses and nasolacrimal ducts

*Superior, Middle and Inferior turbinate with associated meatus

Question 6

Define the epithelium types of the nasal cavity.

Answer 6

Upper = Olfactory epithelium

Most = Pseudostratified ciliated epithelium

Question 7

Nerve supply of nasal cavity?

Answer 7

Upper = CN I (olfactory nerve)

Rest = Br. of Maxillary nerve (V2) and Ophthalmic nerve (V1)

Question 8

Blood supply of nasal cavity?

Answer 8

1) Maxillary artery (ECA) branches: Sphenopalatine*** (lateral wall) and greater palatine arteries (hard palate)
2) Facial artery (ECA) branches: Lateral nasal (lateral wall) and superior labial arteries (nasal septum)
3) Opthalmic artery (ICA) branches: Anterior and Posterior ethmoidal arteries (roof)

Question 9

Venous drainage of nasal cavity?

Answer 9

Pterygoid plexus
Facial vein
Infraorbital vein
Ophthalmic vein

Question 10

Define epistaxis and explain where it occurs?

Answer 10

Nose bleed, caused by trauma, infection ,hypertension

At Kiesselbach area at anterior 1/3 of nose

Question 11

List 5 structures that infection of the nasal cavities may spread to?

Answer 11

Anterior cranial fossa 
Middle ear (via auditory tube) 
Paranasal sinuses 
Lacrimal apparatus 
Conjunctiva

Question 12

Explain the anatomical structures affected to cause CSF rhinorrhea?

Answer 12

Fracture extending to roof of nasal cavity and Cribiform plate of ethmoid bone
» Tear meninges and release CSF

Question 13

Define the paranasal sinuses?

Answer 13

Frontal
Maxillary
Ethmoid
Sphenoid

Question 14

Define the site of drainage of the paranasal sinuses.

Answer 14

Frontal = Frontaonasal duct >> Hiatus Semilunaris 
Maxillary = Posterior Middle meatus via Infundibulum 
Sphenoid = Sphenoethmoidal recess >> opening of sphenoid sinus 

Ethmoid:
Anterior group = Infundibulum + Anterior middle meatus
Middle = Middle meatus above bulla ethmoidalis
Posterior = Superior meatus

Question 15

Which is the most commonly infected paranasal sinus and why?

Answer 15

Maxillary

Opening/ Ostium to this sinus is high up the nasal cavity. Inflammation of the opening canal can easily obstruct drainage and retain mucus

Question 16

Define the 4 connections that the Pterygopalatine fossa makes with other cranial structures.

Answer 16

1) Laterally = infratemporal fossa through pterygomaxillary fissure
2) Medial = Nasal cavity through sphenopalatine foramen
3) Anterior = Orbit through Inferior orbital fissure
4) Posterior = Middle cranial fossa through foramen rotundum and pterygoid canal

Question 17

Content of pterygopalatine fossa?

Answer 17

Maxillary branch of Trigeminal nerve (V2)

Sphenopalatine Artery (through sphenopalatine foramen to nasal cavity) + vein (drain to pterygoid plexus)

Pterygopalatine ganglion

Question 18

List 4 main branches of the maxillary nerve (V2)?

Answer 18

Meningeal branches

Zygomatic branches: zygomaticotemporal and zygomaticofacial

pterygopalatine nerves

Alveolar nerves: anterior, middle and posterior branches

Question 19

What is supplied by the zygomatic branches of V2? ***

Answer 19

Zygomaticotemporal and Zygomaticofacial nerves supply temple and cheek skin

Zygomaticotemporal carries parasym. fibers to lacrimal gland by relaying to lacrimal nerve through Superior orbital fissure

Question 20

What is carried by the ganglionic branches of the V2?

Answer 20

Sensory fibers from the nose, palate and pharynx that pass through the pterygopalatine ganglion

Parasympathetic branches to the lacrimal gland

Question 21

What is supplied by the alveolar nerves branching of V2?

Answer 21

Gum, cheek, upper teeth, maxillary sinus

Question 22

Overall function and branches of the pterygopalatine ganglion?

Answer 22

Secretory motor to lacrimal and nasal glands, Parasympathetic only

Orbital branches&raquo_space; orbit via inf. orbital fissure
Greater and Lesser palatine nerves&raquo_space; palate, tonsil, nasal cavity
Nasal branches&raquo_space; Nasal cavity
Pharyngeal branches&raquo_space; Roof of nasopharynx
Nasopalatine branch&raquo_space; Incisive foramen

Question 23

What tissue forms the flares of the nose?

Answer 23

Alar fibrofatty tissue

Question 24

Blood supply of paranasal sinuses? Nerve supply?

Answer 24

Opthalmic artery (ICA) + Maxillary artery (ECA)

V1 + V2

Question 25

Define the openings at the hiatus semilunaris?

Answer 25

Anterior opening = Anterior ethmoid sinus

Posterior opening = Maxillary sinus

Question 26

Define the parasym and sym nerve input into the Pterygopalatine ganglion? Output branches? **

Answer 26

Parasym: CN7 (through foramen lacerum)&raquo_space; Greater petrosal nerve
Sym: T1-T2 sympathetic chain&raquo_space; Deep petrosal nerve

Greater and Deep petrosal nerves merge to form Vidian nerve through Pterygoid canal to reach pterygopalatine ganglion

Pharyngeal branch
Greater and Lesser palatine nerves
Nasal branch
Nasopalatine nerve

Question 27

Define the connection between the Maxillary nerve and the Pteygopalatine ganglion?

Answer 27

Ganglionic branch of V2/ Pterygopalatine nerve

Question 28

Trace the parasympathetic innervation of the lacrimal glands?

Answer 28

CN7&raquo_space; foramen lacerum&raquo_space; Greater petrosal nerve&raquo_space; Vidian nerve&raquo_space; Pterygopalatine ganglion&raquo_space; Gnalgionic branch of Maxillary nerve&raquo_space; Maxillary nerve&raquo_space; Zygomaticotemporal nerve&raquo_space; Superior orbital fissure&raquo_space; Lacrimal nerve of V1&raquo_space; Lacrimal gland

Question 29

Which branch of the Pterygopalatine ganglion carries special sensory fibers?

Answer 29

Greater palatine nerve&raquo_space; Taste