10. Nasal Cavity

Question 1

Identify the various structures representing the general anatomy of everything surrounding the nasal cavity.

Answer 1

1. red box: cranial cavity
2. yellow : orbits
3. blue: nasal cavity (has openings to the pharynx)
4. purple: oral cavity (has opening to pharynx)
5. green: pharynx (has opening to trachea)
6. white: spinal column
7. red: larynx with the vocal cords (becomes trachea)
8. stripe blue: trachea
9. red cylinder: esophagus
10. purple circle: plural cavity

Question 2

What are the 3 parts of the pharynx?

Answer 2

1. nasopharynx (behind nasal cavity)
2. oropharynx (behind oral cavity)
3. laryngopharynx (behind larynx)

Question 3

Describe the anatomy of the nostrils.

Answer 3

a. roof (formed of ethmoid bone)
b. floor : forms hard palate
c. lateral wall
d. nares (nostrils)
e. choanae (entry to pharynx)
f. conchae: superior, middle, inferior
g. nasal septum =medial wall

Question 4

What structures form the nasal septum?

Answer 4

perpendicular plate of ethmoid + vomer bone

Question 5

Identify the various structures of the ethmoid bone.

Answer 5

pink: crista gali
green: orbital plate (medial)
yellow: ethmoid air cells (lined with mucus)
purple: superior and middle nasal conchae
blue: perpendicular plate of ethmoid
red: vomer

Question 6

How do you know if you’re looking at the medial wall or the lateral wall?

Answer 6

the septum is seen in the medial wall

(trick: if you see outer rim of teeth/mouth: lateral wall, if you see inner rim of teeth: medial wall)

ALWAYS LATERAL WALL IN LAB

Question 7

Identify the structures of this wall. What wall is this?

Answer 7

medial wall:

pink: vomer bone
blue: septal cartilage
green: perpendicular plate of ethmoid

Question 8

Identify the various bone structures.

Answer 8

a. nasal cartilage
b. nasal cartilage
c. nasal bone
d. maxilla bone
e. frontal process of the maxilla bone
f. lacrimal bone (drain tears)
g. ethmoid bone

Question 9

What part of the nose is usually broken?

Answer 9

nasal or septal cartilage

Question 10

Identify the structure in red.

Answer 10

anterior nasal aperture

Question 11

Looking at the inferior view, what are the 2 structures shown below?

Answer 11

blue: medial pterygoid plates (part of the sphenoid bone)
red: choanae (between hard palate and sphenoid bone)

Question 12

Identify the various structures in the medial wall.

Answer 12

a. anterior nasal aperture
b. nasal bone
c. maxilla bone
d. Hard palate = floor = process of maxilla + palatine bone (in green)
e. lacrimal bone
f. ethmoid bone
g. superior nasal chonchae (the smallest of choncae)
h. middle nasal conchae
i. inferior nasal conchae
j. choana
l. sphenoid bone

Question 13

What forms the hard palate?

Answer 13

palatine bone and process of maxilla

Question 14

Identify the structure in red.

Answer 14

sphenoethmoidal recess: highest cavity that hold olfactory fibers

Question 15

What is found beneath each nasal conchae?

Answer 15

1. beneath the superior nasal conchae: superior meatus
2. beneath the middle nasal conchae: middle meatus
3. beneath the inferior nasal conchae: inferior meatus

Question 16

What lines all the meatus and recesses? What is its function? Where do they all drain into?

Answer 16

mucosa: filters, warms and and moistens air. They drain into the nasopharynx

Question 17

What is a sinus?

Answer 17

spaces in skull that have a mucosal lining that connect to nasal cavities to drain mucus into it

Question 18

Identify the paranasal sinuses.

What is their function?

Answer 18

a. frontal sinus
b. maxillary sinuses
c. ethmoid sinuses (in ethmoid air cells)
d. sphenoid sinus

drainage of mucus for swallowing

Question 19

Where does most of the mucus produced by the sinuses go?

Answer 19

they are swallowed into pharynx

Question 20

Identify these two structures.

Answer 20

orange: frontal sinus
yellow: sphenoid sinus

Question 21

Identify the 2 sinuses shown.

Answer 21

orange: frontal sinus
purple: maxillary sinus

Question 22

What is the structure shown in blue. What is its function?

Answer 22

semilunar hiatus: drains frontal, ethmoid, maxillary sinuses

Question 23

Where does the frontal sinus drain into?

Answer 23

frontal sinus drains into the middle meatus by merging into the semilunar hiatus and maxillary sinus

Question 24

Where do the ethmoid air cells drain into?

Answer 24

they drain into the middle and superior meatuses

Question 25

What does the arrow on the left point at? what is the function of this structure?

Answer 25

ethmoid bulla = swelling from middle air cells (visible in middle meatus): it is a landmark for the semilunar hiatus that sits just around it

Question 26

Where does the sphenoid sinus drain into?

Answer 26

into the sphenoethmoidal recess

Question 27

Where does the maxillary sinus drain into?

Answer 27

drains into the middle meatus

Question 28

What does the nasopharynx connect to?

Answer 28

pharyntotympanic tube responsible for equilibrating pressure inside and outside ear

Question 29

What is orbital floor blowout fracture?

Answer 29

maxilla part of bottom orbital breaks and eye produdes out of the eye socket

Question 30

What is frontal lobotomy.

Answer 30

to alter and inject things in the frontal lobe via the top orbital plate which is very thin

Question 31

what occurs in a sinus infection?

Answer 31

things can drain into sinus such as bacteria. Pain can be referred onto maxillary teeth because nerve travels through sinuses

Question 32

Identify the various structures and their function. explain the trajectory of tears.

Answer 32

left arrow: lacrimal gland: produces tear that travels laterally into lacrimal puncta top arrow: lacrimal caniculi = duct that goes into lacrimal duct (found under the inferior nasal conchae) yellow: lacrimal sac bottom arrow: inferior nasal conchae red: nasolacrimal duct: drains tear into inferior meatus

Question 33

What is a way to get something out of your eye if its stuck?

Answer 33

look up and out to produce more tears then look back down which moves the think to the inner corner of the eye

Question 34

Explain the innervation of the lateral wall of the nasal cavity

Answer 34

1. olfactory nerves send out fiber into sphenoethmoidal recess 2. ethmoidal nerve (branch of CN V1) does sensory innervation of anterior wall of nasal cavity 3. upper half from bottom of nostril up diagonally innervated by CN V1, the bottom is innervated by CN V2 4. through the sphenopalatine foramen: nasal n (branch of CN V2) does bottome half

Question 35

Explain the innervation of the medial wall of the nasal cavity.

Answer 35

1. olfactory n (special sensory) 2. ethmoidal n that does sensory innervation of anterior nose 3. nasopalatine n (branch of CN V2) innervates bottom half and travels through the incisive canal 4. upper half from bottom of nostril up diagonally innervated by CN V1, the bottom is innervated by CN V2

Question 36

Explain the blood supply in the lateral wall of the nasal cavity.

Answer 36

1. ethmoidal a: goes to anterior nose 2. through the sphenopalatine foramen: sphenopalatine a and anastomose with branches of superior labial a (from facial a) 3. through incisive canal: greater palatine anastomose sphenopalatine a 4. maxillary a from external carotid a

Question 37

Explain the blood supply in the medial side of the nasal cavity.

Answer 37

1. ethmoidal a does superior and anterior nose anastomes with superior labial a from facial a 2. sphenopalatine a: goes through incisive foramen and anastomes with greater palatine a

Question 38

What is the most common site of nose bleeds?

Answer 38

on medial wall of nasal cavity: ethmoidal a, superior labial a, sphenopalatine a