The Nose, Nasal Cavity and Paranasal Sinuses

Question 1

Through which bone would a surgeon need to drill to gain access to the pituitary gland?

Answer 1

sphenoid

Question 2

What is the function of the nose and nasal cavity?

Answer 2

Olfaction

Filtering

Humidifying inspired air

Warms air – highly vascular

Drainage of secretions from paranasal sinuses and nasolacrimal ducts

Resonating chamber for speech

Question 3

What is the vestibule?

Answer 3

Inner part of the external nose

Lining = skin, hair, sebaceous glands

Question 4

What makes up the bony part of the external nose?

Answer 4

Nasal bone

Frontal process of maxilla

Question 5

Describe the anatomy of the nasal cavity?

Answer 5

Lining = mucous membrane

Conchae = superior, middle, inferior

Meatus = space under bony shelf, passage to sinuses

Question 6

What cranial nerve allows for olfaction?

Answer 6

CN I

Question 7

What lines the nasal cavity?

Answer 7

Olfactory mucous membrane = smell

Respiratory mucous membrane = pseudostratified columnar ciliated ep, filters, humidifies, warms

Question 8

What are the boundaries of the nasal cavity?

Answer 8

Medial = perpendicular plate of ethmoid bone, vomer

Lateral = maxilla, conchae

Roof = frontal bone, sphenoid bone, nasal bone, cribiform plate

Floor = hard palate

Question 9

The irregular nature of the lateral wall in the nasal cavity, enables what?

Answer 9

Turbulent air flow

Increased surface area

Question 10

Outline the vascular supply to the nasal cavity

Answer 10

Sphenopalatine artery = bleeding potential more serious/diff to treat

Greater palatine artery

Superior labial

Posterior ethmoid

Anterior ethmoid

Question 11

What are paranasal sinuses?

Answer 11

Reduce weight of skull = filled with air

Humidify and warm inspired air

Mucus from here drains to nasal cavity

Question 12

Name the paranasal sinuses

Answer 12

Maxillary – largest

Frontal

Ethmoidal

Sphenoid

Question 13

What are the paranasal sinuses lined with?

Answer 13

Respiratory mucosa = ciliated pseudostratified columnar with goblet cells

Question 14

What CN carries general sensation to the nasal cavity?

Answer 14

Trigeminal N – ophthalmic, maxillary

Question 15

Describe nasal polyps

Answer 15

Fleshy, benign swellings of nasal mucosa

Usually bilateral

Blocked nose and water rhinorrhoea

Post-nasal drip

Decreased smell/reduced taste

Question 16

What is the nervous supply to the paranasal sinuses

Answer 16

Va (trigeminal ophthalmic) = frontal, ethmoidal, sphenoid

Vb (trigeminal maxillary) = maxillary

Question 17

Define epistaxis

Answer 17

Nose bleed

Question 18

What is the most common site for nose bleeds?

Answer 18

Keisselbacks plexus

Question 19

Arterial supply to the nasal cavity arises from where?

Answer 19

Branches of ophthalmic artery and maxillary artery

Question 20

Outline the venous drainage from the nasal cavity

Answer 20

Drains into the pterygoid venous plexus, cavernous sinus and facial vein

Question 21

What is rhinitis?

Answer 21

Infam of mucosal lining

Nasal congestion, rhinorrhoea, sneezing, nasal irritation, post-nasal drip

Causes = viral common cold, allergic rhinitis

Question 22

Describe a nasal fracture

Answer 22

Nasal bone is most prone to fracture

Often hidden by swelling = wait to subside

Question 23

What is a septal haematomas?

Answer 23

Blood collects in space between cartilaginous septum and its perichondrium = no blood supply

Untreated = irreversible avascular necrosis = distortion = saddle-nose deformity

Examine = swelling from medial part of nasal cavity

Question 24

Describe sinusitis

Answer 24

Inflam of the lining of the sinuses

Primary infection = mucosal oedema = impedance of ciliary function = increased mucosal secretions = obstruction to drainage from a paranasal sinus = accumulation of mucosal secretions = secondary infection by bacteria

Maxillary sinus particular prone

Self-limiting