The Nose and Paranasal Air Sinuses 2

Question 1

In the lateral wall of the nasal cavity, there is an opening from the maxillary air sinus to …. ….

Answer 1

The nasal cavity.

Question 2

Above the opening in the lateral wall of the nasal cavity from the maxillary air sinus to the nasal cavity, what is the lateral wall of the nasal cavity formed by?

Answer 2

It is formed by the ethmoid bone.

Question 3

What does the cribriform plate form?

Answer 3

It forms the roof of the nose and the floor of the anterior cranial fossa.

Question 4

What is the crista galli?

Answer 4

This is a midline projection of the cribriform plate.

Question 5

What is the downward projection of the cribriform plate called?

Answer 5

It is called the perpendicular plate of the ethmoid.

Question 6

What does the cribriform plate form part of?

Answer 6

It forms part of the midline nasal septum.

Question 7

On either side, what is the cribriform plate expanded by?

Answer 7

It is expanded by numerous air cells.

The lateral walls of the air cells lie in the medial walls of the orbital cavities.

Question 8

What do the ethmoid air cells expand into the top of the nasal cavity to form?

Answer 8

They form the anterior, middle and posterior groups of ethmoidal air cells or sinuses.

Question 9

What are conchae?

Answer 9

These are bony processes in the nasal cavity that curl over the air sinuses in the lateral wall of the nose.

Question 10

How many conchae are there?

Answer 10

3 - superior, middle and inferior.

Question 11

What are the superior and middle conchae a part of?

Answer 11

They are a part of the ethmoid bone.

Question 12

Is the inferior conchae a part of any bone?

Answer 12

It is a separate bone.

Question 13

What do we have beneath each concha?

Answer 13

We have a meatus or a pocket.

Question 14

Which bones form the midline nasal septum?

Answer 14

• above – perpendicular plate of the ethmoid
• below – a thin flat bone called the vomer
  
  • extends from behind like a wedge between the cranial base and the floor of the nose.
• midline septum continues anteriorly as a cartilaginous septal cartilage.

Question 15

What are the paranasal air sinuses lined with?

Answer 15

They are lined with respiratory mucous membrane.

Question 16

Describe the nerve and blood supply to the paranasal air sinuses.

Answer 16

They have a sensory nerve supply and a rich blood supply.

Question 17

What do the paranasal air sinuses open into?

Answer 17

They open into the cavity of the nose.

Question 18

What is the shape of the maxillary air sinus?

Answer 18

It is pyramidal in shape.

Question 19

What is the base of the maxillary air sinus?

Answer 19

The lateral wall of the nose.

Question 20

Where is the apex of the maxillary air sinus?

Answer 20

Near the zygomatic bone.

Question 21

What does the roof of the maxillary air sinus consist of?

Answer 21

It consists of the floor of the orbit.

Question 22

Where does the infraorbital canal lie?

Answer 22

It lies in the roof of the maxillary air sinus.

Question 23

Where does the anterior wall of the maxillary air sinus lie?

Answer 23

It lies behind the cheek.

Question 24

What do we have behind the posterior wall of the maxillary air sinus?

Answer 24

We have the pterygomaxillary fissure and the pterygopalatine fossa.

Question 25

Describe the floor of the maxillary sinus.

Answer 25

The tips of the roots of several teeth create irregular bumps.

Question 26

What are the tooth roots embedded in?

Answer 26

They are embedded in the alveolar bone of the maxilla.

Question 27

What happens when the maxillary air sinus becomes infected?

Answer 27

The respiratory mucous membrane swells and fluid can collect in the cavity which can be painful (especially when bending forwards) in the face or in the top teeth.

Question 28

What is the ostium?

Answer 28

This is a hole through which the maxillary sinus drains.

Question 29

Where is the ostium?

Answer 29

This is high in the lateral wall of the nose beneath the middle concha at the front of a groove called the hiatus semilunaris.

Question 30

What does the hiatus semilunaris run around?

Answer 30

It runs around the base of a swelling that is formed by a bulging of some of the ethmoidal air cells.

Question 31

What is the bulla ethmoidalis?

Answer 31

This is a swelling that is formed by the bulging of some ethmoidal air cells which protrudes a little into the middle meatus.

Question 32

What do the air cells of the ethmoid bone drain into?

Answer 32

They drain into the cavity of the nose.

Question 33

How do the air cells of the ethmoid bone drain into the cavity of the nose?

Answer 33

Through holes that open under the middle and superior meati.

Question 34

What do the sphenoidal air sinuses drain into?

Answer 34

They drain into the nose.

Question 35

How do the sphenoidal air sinuses drain into the nose?

Answer 35

Through 2 openings high in the roof of the nose at the back in a region called the sphenoethmoidal recess.

Question 36

What does each frontal bone also contain?

Answer 36

It also contains an air sinus lateral to the midline.

(Sometimes there is a common sinus and sometime or another one or the other air sinus will be absent)

Question 37

How does the frontal sinus drain into the nose?

Answer 37

It drains into the nose on either side through a funnel like opening called the infundibulum.

Question 38

What does the frontal sinus empty into?

Answer 38

It empties into the front of the hiatus semilunaris.

Question 39

What structure empties into the inferior meatus?

Answer 39

The nasolacrimal duct.

Question 40

Where does the opening of the auditory tube lie?

Answer 40

It lies at the level of the floor of the nose.

Question 41

What type of nerve is the trigeminal nerve?

Answer 41

This is a mixed cranial nerve.

Question 42

What is trigeminal nerve like in size compared to other cranial nerves?

Answer 42

it is the largets cranial nerve.

Question 43

What does the large ganglion of the trigeminal nerve contain?

Answer 43

It contains the cell bodies of its sensory fibres.

Question 44

Where is the large ganglion of the trigeminal nerve?

Answer 44

This lies in the middle cranial fossa, in a depression on the apex of the petrous temporal bone.

Question 45

What happens to the trigeminal nerve as it grows forward during development?

Answer 45

• pushes underneath the dura mater of the middle cranial fossa
• eventually the dura fuses around the trigeminal nerve
• draws a layer of the arachnoid mater with it up to the point where the dura fuses around the trigeminal nerve

Question 46

What are the first part of the nerve and its sensory ganglion bathed in?

Answer 46

They are bathed in cerebrospinal fluid in a subarachnoid space that lies beneath the dura of the middle cranial fossa.

Question 47

What is Meckel’s cave?

Answer 47

This is the space where the subarachnoid space lies beneath the dura of the middle cranial fossa.

Question 48

What happens to the trigeminal nerve beyond its large, sensory ganglion?

Answer 48

It divides into 3 branches on the floor of the middle cranial fossa.

Question 49

What are the 3 divisions of the trigeminal nerve?

Answer 49

• opthalmic division
• maxillary nerve
• mandibular division

Question 50

What is the path of the opthalmic division of the trigeminal nerve?

Answer 50

It passes forwards through the superior orbital fissure into the orbit.