Lecture 14 and (15?): Nasal cavity

Question 1

What is sinusitis?

Answer 1

Sinusitis or sinus infection is inflammation of the air cavities within the passages of the nose.

Question 2

What are nasal polyps

Answer 2

Nasal polyps are soft, painless, noncancerous growths on the l_ining of your nasal passages_ or sinuses.

They hang down like teardrops or grapes. They result from chronic inflammation due to asthma, recurring infection, allergies, drug sensitivity or certain immune disorders. Small nasal polyps may not cause symptoms.

Question 3

What is this?

Answer 3

A nasal septal hematoma is a collection of blood within the septum of the nose. The septum is the part of the nose between the nostrils. An injury disrupts the blood vessels so that fluid and blood may collect under the lining.

Can be dangerous

Question 4

What is this?

Answer 4

Nasal polyps

Question 5

What is Nasal Septal hematoma?

Answer 5

A nasal septal hematoma is a collection of blood within the septum of the nose.

The septum is the part of the nose between the nostrils. An injury disrupts the blood vessels so that fluid and blood may collect under the lining.

Question 6

Where is the nasal cavity located?

Answer 6

The nasal cavity is located:

1) above the oral cavity,

2) anterior to the nasopharynx

3) below the cranial cavity. I

Question 7

What are the 3 regions of the nasal cavity called?

Answer 7

Consists of three regions; the nasal vestibule (1), the respiratory region (2) and the olfactory region (3).

• The nasal vestibule is a small, dilated space (located anteriorly) and lined by skin and contains hair follicles; entrance to the nasal cavity.
• The respiratory region is largest part and has a rich neurovascular supply. It is lined by respiratory epithelium (ciliated and mucus cells), also extra bones going inside the cavity (increases its surface area). It adjusts temperature and humidity of inspired air.
• The olfactory is a small part at the apex of the cavity and is lined by olfactory epithelium and contains the olfactory receptors.

Question 8

Describe the Nasal vestibule region of the nasal cavity

Answer 8

• The nasal vestibule is a small, dilated space (located anteriorly) and lined by skin and contains hair follicles; entrance to the nasal cavity.

Question 9

Describe the Respiratory region of the nasal cavity

Answer 9

The respiratory region is largest part and has a rich neurovascular supply.

It is lined by respiratory epithelium (ciliated and mucus cells), also extra bones going inside the cavity (increases its surface area).

It adjusts temperature and humidity of inspired air.

Question 10

Describe the Olfactory region of the nasal cavity

Answer 10

• The olfactory is a small part at the apex of the cavity and is lined by olfactory epithelium and contains the olfactory receptors.

Question 11

Describe the skeletal framework of the nasal cavity (8)

Answer 11

Bones which contributes to the skeletal framework of the nasal cavities include:

• Unpaired ethmoid (1), sphenoid (2), frontal (3) and vomer bones
• Paired nasal (4), maxillary (5), palatine (6) and lacrimal (7) bones and i_nferior conchae (8)._

The e_thmoid bone_ is a key element of the skeletal framework of the nasal cavity.

Question 12

What is the external nose made up of?

Answer 12

Anterior parts of nasal cavities found within nose are held open by a skeletal framework, which is composed partly of bone and mainly of cartilage (and connective tissue):

The most important cartilage: Septal cartilage. (if there’s bleeding due to trauma it needs to be drained!)

(don’t need to know the names of the different parts of the cartilage)

• Posteriorly, support is provided by bony parts (nasal bones and parts of maxillae and frontal bones).
• Anteriorly, support is provided by lateral processes of septal cartilage, major alar and three/four minor alar cartilages, and a single septal cartilage in the midline that forms the anterior part of the nasal septum.

Question 13

Anterior parts of nasal cavities found within nose are held open by a skeletal framework, which is composed partly of _____ and mainly of ______ (and _______):

Answer 13

Anterior parts of nasal cavities found within nose are held open by a skeletal framework, which is composed partly of bone and mainly of cartilage (and connective tissue):

Question 14

Label the parts of the external nose (don’t need to know for the exam)

Answer 14

1) Lacrimal bone
2) Nasolacrimal groove
3) Frontal process of maxilla
4) Lateral process of septal cartilage
5) Lateral process of septal cartilage
6) Superior margin of septal cartilage (septal cartilage in the midline)
7) Superior margin of septal cartilage
8) Major alar cartilage
9) Major alar cartilage
10) Septal cartilage
11) Minor alar cartilages

Question 15

_______ is the growth plate of the nasal cavity

Answer 15

Cartilages of the external nose

so if a baby damages the cartilages, the nose may not develop as it should- one side may grow and not the other.

(mid face abnormality)

Question 16

What external cartilage is associated with trauma?

Answer 16

Septal cartilage

Question 17

Floor of the nasal cavity is the same as the _______

Answer 17

Roof of the oral cavity

Question 18

Describe the floor of the nasal cavity

Answer 18

It consists of:

• Soft tissues of the external nose, and
• The upper surface of palatine process of maxilla and the h_orizontal plate of palatine bone,_ which together form h_ard palate._
  
  • ​There is also nasal crest (of the maxilla and palatine bone) that comes up the middle

The naris opens anteriorly into the floor, and the superior aperture of the incisive canal is deep to the mucosa immediately lateral to the nasal septum near the front of the hard palate.

Question 19

What bones make up the roof of the nasal cavity?

Answer 19

1) Most anterior (most likely to be fractured): Nasal bone
2) Nasal spine of the frontal bone
3) The roof of the nasal is cavity is highest in central regions where it is formed by the cribriform plate and the Crista Guli of the ethmoid bone.
4) Sphenoid bone

__________________

The roof of the nasal is cavity is highest in central regions where it is formed by the cribriform plate of the ethmoid bone.

• Anterior to cribriform plate, roof slopes inferiorly to the nares and is formed by: nasal spine and nasal bones; and lateral processes of septal cartilage and major alar cartilages of external nose.
• Posteriorly, troof of each cavity slopes inferiorly to choana and is formed by: anterior surface of sphenoid bone, the ala of vomer and adjacent sphenoidal process of palatine bone, and vaginal process of medial plate of pterygoid process.

Underlying the mucosa, the roof is perforated superiorly by openings in the cribriform plate, and anterior to these openings by a separate foramen for the anterior ethmoidal nerve and vessels. The opening between the sphenoidal sinus and the spheno-ethmoidal recess is on the posterior slope of the roof.

Question 20

The roof of the nasal is cavity is highest in central regions where it is formed by the _______of the ______

Answer 20

The roof of the nasal is cavity is highest in central regions where it is formed by the cribriform plate and the Crista guli of the ethmoid bone.

Question 21

What bone that forms the nose is most likely to be fractured?

Answer 21

Nasal bone

Question 22

Describe the parts of the ethmoid bone

Answer 22

Parts we need to know:

1) Superior concha
2) Inferior concha
3) Cribiform plate
4) Perpendicular plate (may be fractured in trauma)
5) Infundibulum (drain back into the nose. communicate between nasal cavity and sinus)
6) Crista gali
7) Middle concha
8) Uncinate process

Question 23

Describe the Medial wall of the nasal cavity

Answer 23

Medial wall is just the septum (separates the left and right nasal cavity)

Nasal septum consists of:

• The s_eptal nasal cartilage_ anteriorly,
• Posteriorly, mainly the vomer and the perpendicular plate of the ethmoid bone,
• Small contributions by the nasal bones where they meet in the midline, and the nasal spine of the frontal bone, and
  
  • Contributions by nasal crests of maxillary and palatine bone, rostrum of sphenoid bone, and incisor crest of the maxilla.

____________ below= what? __________

Clinically this is important in trauma because we may get damage to the nasal bone, fracture in the perpendicular plate of the ethmoid bone or haematoma in the cartilagenous bone.

Formed by:

1) Nasal bone

2) Septal cartilage

3) Perpendicular plate of the ethmoid bone

4) Vomer

5 & 6) Some crest of the maxila and palatine bone

Question 24

What bones make up the Lateral wall of the nasal cavity (12)

Answer 24

Bony support for the lateral wall is provided by:

1) Superior and Middle concha (ethmoid bone)
2) Inferior concha
3) Nasal bone
4) Frontal process of Maxilla
5) Perpendicular plate of palatine bone
6) Lateral process of septal cartilage
7) Major alar
8) Minor Alar
9) Medial pharyngoid plate of sphenoid bone
10) A bit of frontal bone
11) Lacrimal bone * eventually drain the lacrimal duct
12) Vomer * (don’t forget)

Question 25

Which concha are part of which bones?

Answer 25

Superior and Middle concha are part of the ethmoid bone Inferior concha is a separate bony structure.

Question 26

Why is the lateral wall of the nasal cavity important?

Answer 26

Sinuses drain into the lateral wall. So if the patient has sinusitis, you need to examine the nasal cavity to see where the infection is. Look at the concha. The shape changes. You must be able to differentiate between normal concha, nasal polyp and nasal haematoma

Question 27

EXAM \* how do you differentiate between normal concha, nasal polyps and nasal haematoma?

Answer 27

Question 28

Name the different paranasal sinuses

Answer 28

There are four paranasal sinuses; the **_ethmoidal cells (1_**), and the **_sphenoidal (2),_** **_maxillary (3),_** and **_frontal sinuses (4)_**. Each sinus is named according to the bone in which it is found. * They develop as outgrowth from the nasal cavity and erode into the surrounding bones (e.g., Frontal sinus is absent at birth, others are rudimentary, expanding between 6-7 years and again post-puberty). * All sinuses are lined by **respiratory *mucosa*,** which is ciliated and mucus secreting and open into the nasal cavity. * They are innervated by branches of **trigeminal nerve** (V).

Question 29

If there's tumour in the pituitary gland, what's the easiest way to get to the gland?

Answer 29

Nasal cavity- sphenoidal sinus- pituitary gland

Question 30

Where do the parasinuses drain?

Answer 30

(don't need to know full name, just know where in relation to the conchae) * **_Frontal_**: * It drains onto the lateral wall of the **middle meatus** via the **frontonasal duct**, which penetrates the **ethmoidal labyrinth** and continues as the **ethmoidal infundibulum** at the front end of the **semilunar hiatus**. * (Anterior and under the middle concha) * **_Maxillary_**: * Opens into **semilunar hiatus**, usually just inferior to the centre of the ethmoidal bulla - this opening is near the roof of the maxillary sinus. * Under the middle concha in the middle. * **_Ethmoidal_**: * **_Anterior cells_** open into the **ethmoidal infundibulum or the frontonasal duct**; * **_Middle cells_** open onto the **ethmoidal bulla**, or onto the lateral wall just above this structure. * _**Posterior** ethmoidal cells_ open onto the _lateral wall of the **superior** nasal meatus_ (nasal meatuses are located beneath each of the corresponding nasal conchae). * **_Sphenoid_**: * The only paranasal sinus that does not drain onto the lateral wall of the nasal cavity. * It usually opens onto the sloping posterior roof of the nasal cavity, i.e. the **roof** of the nasal cavity (**_Spheno-ethmoidal recess_**)

Question 31

Which sinus is the only sinus that does not drain into the lateral wall?

Answer 31

**_Sphenoid_**: The only paranasal sinus that does not drain onto the lateral wall of the nasal cavity. It usually opens onto the sloping posterior roof of the nasal cavity, i.e. the roof of the nasal cavity **_(Spheno-ethmoidal recess)_**

Question 32

Where does the nasolacrimal duct drain?

Answer 32

Deep to the inferior nasal concha

Question 33

What are some gateways into the nasal cavity

Answer 33

1) Incisive canal 2) Cribiform plate 3) Sphenopalatine foramen 4) Small foramina on lateral wall There are several routes by which nerves and vessels enter and leave the soft tissue lining each nasal cavity. Here, only very important clinically structures are listed below: 1. **Cribriform plate: (a)** fibres of olfactory nerve; (b) anterior ethmoidal nerve of V1 and accompanying vessels; (c) nasal veins connecting to superior sagittal sinus 2. **Sphenopalatine foramen:** (a) *sphenopalatine branch* of *maxillary artery*; (b) nasopalatine branch of V2; (c) superior nasal branches of V1 3. **Incisive canal: (a)** nasopalatine nerve; (b) terminal part of greater palatine artery 4. **Small foramina in the lateral wall:** (a) branch of the infraorbital nerve (V2); (b) branch of greater palatine nerve (V2)

Question 34

Describe the blood supply to the nasal cavity

Answer 34

Arteries that supply the nasal cavity include vessels that originate from **both** ***internal*** and ***external* carotid artery**. * Branches of external carotid artery include _sphenopalatine_, greater palatine, superior labial, and lateral nasal arteries. * Branches of internal carotid artery are anterior and posterior ethmoidal arteries. **_Anterior_** part of the nasal cavity is supplied by anastamoses **_Posterior_** part is mainly supplied by the ***sphenopalatine artery*** **(1),** which is end of maxillary artery passing through _sphenopalatine foramen_*,* * It supplies both lateral and medial walls of nasal cavity, it is most common site of _posterior epistaxis_. However, it still contributes to Little’s area by giving a branch, which is posterior septal branch of sphenopalatine artery * It anastomoses with septal branch of ***superior labial*** **(2)** and ascending branch of ***greater palatine*** **(3)** (through incisive foramen) over *lower anterior* part of **septum** (medial wall) where it forms **_Kieselbach’s plexus**_ (_**Little’s area_**) (common site for _anterior epistaxis_). Anterior and posterior ethmoidal arteries (branches of internal carotid artery) supply roof and anterior part of *lateral wall*. Lateral wall is supplied by alar branch of lateral nasal artery, anterior and posterior ethmoidal artery, but mainly sphenopalatine artery covers lateral wall for the conchae.

Question 35

If someone comes in with posterior nasal bleeding, it has to do with the _______ artery If you see this, you need to send them to a bigger centre within hours

Answer 35

Sphenopalatine artery

Question 36

What is a common area of anterior epistaxis

Answer 36

Kieselbach’s plexus (Little’s area) (common site for anterior epistaxis). Epistaxis, or bleeding from the nose, is a common complaint. [1] It is rarely life threatening but may cause significant concern, especially among parents of small children.

Question 37

Sphenopalatine artery is an artery which is end of ______ passing through \_\_\_\_\_\_\_\_. It supplies \_\_\_\_\_\_\_walls of nasal cavity

Answer 37

sphenopalatine artery (1), which is end of _maxillary artery_ passing through _sphenopalatine foramen,_ It supplies both l_ateral and medial walls_ of nasal cavity

Question 38

Describe the Venous drainage of the nasal cavity

Answer 38

_Facial vein_, o_phthalmic vein_ and _inferior cerebral vein_ ***(danger triangle)*** drain to **pterygoid** plexus in infratemporal fossa, then can go to external veins or cavernous sinus back up into the cranium.

Question 39

Describe the Nerve supply to the nasal cavity

Answer 39

**_General sensation_** of the nasal cavity comes from _V1 and V2_ _Parasympathetic and sympathetic_ come into cavity thru maxillary nerve (V2) via ptergopalatine fossa. * **Sympathetic** originate from _cervical plexus:_ *_T1,_ cervical ganglion*. * **Parasympathetic** originates from *f_acial nerve (_greater petrosal nerve)*.

Question 40

General sensation of the nasal cavity comes from \_\_\_\_\_

Answer 40

General sensation of the nasal cavity comes from V1 and V2

Question 41

The \_\_\_\_\_bone is a key element of the skeletal framework of the nasal cavity

Answer 41

The ethmoid bone is a key element of the skeletal framework of the nasal cavity

Question 42

Label

Answer 42

the unpaired ethmoid (1), sphenoid (2), frontal (3) and vomer bones - the paired nasal (4), maxillary (5), palatine (6) and lacrimal (7) bones and inferior conchae (8). The ethmoid bone is a key element of the skeletal framework of the nasal cavity

Question 43

How do the paranasal sinuses develop?

Answer 43

They adevelop as _outgrowth from the nasal cavity_ and _erode into the surrounding bones_ (e.g., Frontal sinus is absent at birth, others are rudimentary, expanding between 6-7 years and again post-puberty)

Question 44

All sinuses are lined by \_\_\_\_\_\_\_and open into the \_\_\_\_\_

Answer 44

All sinuses are lined by _respiratory mocusa_ and open into the _nasal cavity;_

Question 45

- the frontal sinuses, anterior and middle ethmoidal cells and maxillary sinuses open onto \_\_\_\_\_\_\_\_\_\_\_\_\_ - the posterior ethmoidal cells open onto the \_\_\_\_\_\_\_\_\_\_\_\_\_\_ - the sphenoidal sinuses open into the \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Answer 45

- the frontal sinuses, anterior and middle ethmoidal cells and maxillary sinuses open ontothe lateral wall of the **middle meatus.** - the posterior ethmoidal cells open onto the s**uperior nasal meatus.** - the sphenoidal sinuses open into the roof of the **nasal cavity (sphenoethmoidal recess).**

Question 46

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ open ontothe lateral wall of the middle meatus. \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_open onto the superior nasal meatus. \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_open into the roof of the nasal cavity (sphenoethmoidal recess).

Answer 46

- the **_frontal sinuses_****, _anterior and middle ethmoidal cells_** and **_maxillary sinuses_** open ontothe lateral wall of the middle meatus. - the **_posterior ethmoidal cells_** open onto the superior nasal meatus. - the **_sphenoidal sinuses_** open into the roof of the nasal cavity (sphenoethmoidal recess).

Question 47

Sinuses are innervated by branches of trigeminal nerve (CN V): - Frontal sinuses are innervated by \_\_\_\_ - Maxillary sinuses are innervated by \_\_\_\_ - The ethmoidal cells are innervated by \_\_\_\_\_\_\_ - Sphenoid sinuses are innervated by \_\_\_\_\_\_\_

Answer 47

They are innervated by branches of trigeminal nerve **(CN V):** - Frontal sinuses are innervated by **CN V1.** - Maxillary sinuses are innervated by **CN V2.** - The ethmoidal cells are innervated by **CN V1 and CN V2.** - Sphenoid sinuses are innervated by **CN V1 and CN V2.**

Question 48

What travels through the Cribiform plate?

Answer 48

- Cribriform plate (1) 1- the _fibres of CN 1_ 2- the _anterior ethmoidal nerve of CN V1_ and accompanying vessels 3- the _nasal veins_ connecting to the supperior sagittal sinus

Question 49

What travels through the Sphenopalatine foramen

Answer 49

1- the sphenopalatine branch of the maxillary artery 2- the nasopalatine branch of CN V2 3- Superior nasal branches of CN V1

Question 50

What travels through the Incisive canal?

Answer 50

1- the nasopalatine nerve 2- the terminal part of the greater palatine artery

Question 51

What travels through the samll foramina in the lateral wall?

Answer 51

- Small foramina in the lateral wall (4) 1- a branch of the infraorbital nerve (CN V2) 2- a branch of the greater palatine nerve (CN V2)

Question 52

Describe the lymph drainage of the nasal cavity

Answer 52

Runs with the veins rather than the arteries, and drains to the submandibular, deep cervical and retropharyngeal nodes

Question 53

What is this area?

Answer 53

Little's area (prone to nosebleeds)

Question 54

The main artery that supplies the nasal cavity is the\_\_\_\_\_\_\_. It anastomoses with the \_\_\_\_\_\_\_\_\_\_\_\_and ascending branch of the ________ overthe lower anterior part of the septum (Little’s area) where it forms the \_\_\_\_\_\_/ Kieselbach’s plexus is a common site for anterior epistaxis. The anterior and posterior ethmoidal arteries supply the roof and the anterior part of the lateral wall. The veins drain to the pterygoid plexus, which includes the facial vein, ophthalmic vein and inferior cerebral vein.

Answer 54

The main artery is the **sphenopalatine artery (1)** (the end of the maxillary artery passing through the sphenopalatine foramen). It anastomoses with the septal branch of the **superior labial (2**) and ascending branch of the g**reater palatine (3)** over the lower anterior part of the septum (Little’s area) where it forms the **Kieselbach’s plexus.** Kieselbach’s plexus is a common site for anterior epistaxis. The anterior and posterior ethmoidal arteries supply the roof and the anterior part of the lateral wall.

Question 55

All of the veins in the nasal cavity drain into...

Answer 55

The veins drain to the **pterygoid plexu**s, which includes the facial vein, ophthalmic vein and inferior cerebral vein.

Question 56

Describe the nerve supply to the different areas of the nasal cavity (olfactory, vestibular, respiratory)

Answer 56

**The olfactory area (1)** is supplied via the _olfactory receptors,_ which are extensions of the _olfactory nerve_ - The **vestibular area (2)** is supplied via the _infraorbital nerve_ - The **respiratory area (3**) is supplied anteriorly via the _anterior ethmoidal nerve (through cribiform plate)_ and the _anterior superior alveolar nerve (from ptergoidpalatine foramen)_ and posteriorly via branches from the _pterygopalatine ganglion_ and the _greater palatine nerve_