ICL 1.1: Anatomy of Upper Respiratory Track, Nasal Cavity and Larynx

Question 1

what are the components of the upper respiratory system?

Answer 1

1. nose
2. paranasal sinuses
3. pharynx (nasopharynx and oropharynx; laringopharynx is part of the digestive system)

Question 2

what are the components of the lower respiratory system?

Answer 2

1. larynx
2. respiratory tree = trachea, bronchi, bronchioles
3. respiratory surface of the lungs

Question 3

why is the respiratory system divided the way it is?

Answer 3

it has no anatomical basis; it’s based on the spread of infection

URI = rhinitis, sinusitis or pharyngitis

LSI = laryngitis, bronchitis, bronchiolitis, pneumonia

Question 4

what makes up the bony skeleton of the external nose?

Answer 4

1. nasal bones (2)
2. frontal processes of maxilla (2)
3. nasal processes of the frontal bone

Question 5

what makes up the cartilaginous framework of the external nose?

Answer 5

1. lateral nasal cartilage
2. alar cartilage
3. septal cartilage

these make up the majority of the nose that you see externally and they attach to the external nasal aperture.piriform opening which is the hole for the nose you see on a skull

Question 6

what are the 3 regions of the nasal cavity?

Answer 6

1. vestibule = skin with hair (vibrissae) –> most front part
2. transition area = nonkeratinized skin
3. respiratory area = pseudostratified ciliated epithelium with goblet cells
4. olfactory area = sensory olfactory epithelium where CN1 emerges through the cribriform plate –> most back located part

Question 7

what are the 4 walls of the nasal cavity?

Answer 7

1. roof
2. floor
3. lateral wall
4. medial (septal) wall

floor is wider than the roof; roof is narrow

the nasal cavity is divided into right and left halves by the nasal septum

Question 8

what is located anatomically above the nasal cavity?

Answer 8

cribiform plate of the ethmoid bone forms the roof of the nasal cavity

above this bone, dura separates the nasal cavity from the frontal lobe of the brain

Question 9

what is located below the nasal cavity?

Answer 9

the hard palate forms the floor of the nasal cavity and separates it from the oral cavity below

Question 10

what is located lateral to the nasal cavity?

Answer 10

the orbit is above the lateral wall and the maxillary sinus below

Question 11

what is the function of the roof of the nasal cavity? what are the 2 segments of the roof of the nasal cavity?

Answer 11

it’s very narrow transversely and separates the nasal cavity from the frontal lobe in the anterior cranial fossa

it’s formed by:
1. the cribiform plate of the ethmoid –> forms the anterior and longest part

2. body of the sphenoid –> sphenoid forms the posterior part

Question 12

what do you need to be careful of with the roof of the nasal cavity?

Answer 12

the cribriform plate of ethmoid is a weak spot of the cranial base because of all the little foramina in it so it can be broken even with minor head trauma causing CSF leak through the nasal cavity

patients in the ER leaking clear fluid from the nose after head trauma like with MVA, with no prior history of nasal discharge you need to be very worried that they broke their cribiform plate!

Question 13

what does the roof of the nasal cavity provide you access to?

Answer 13

the roof of the nasal cavity provide an easy access to the pituitary gland to surgically operate on the gland (trans-nasal/transsphenoidal approach)

so you go through the nose, break through the sphenoid bone, go through the sphenoid sinus then break through the back of the bone into the sella turcica where the pituitary gland sits

ancient Egyptians used to remove the brain from the skull using a hook through trans-nasal/transsphenoidal approach to remove the brain during the process of mummification

Question 14

what is the medial wall of the nasal cavity? what is it made up of?

Answer 14

it’s the nasal septum which divides the nasal cavity into quite often unequal halves

it’s made of:
1. septal cartilage inferoanteriorly

2. perpendicular plate of the ethmoid superiorly
3. vomer inferoposteriorly

Question 15

what is the floor of the nasal cavity? what is it made up of?

Answer 15

the floor of the nasal cavity separates the nasal cavity from oral cavity

the floor is formed of the hard plate = palatine process of the maxilla + horizontal plate of palatine bone

Question 16

what is the lateral wall of the nasal cavity made up of?

Answer 16

the superior part is made of the ethmoid bone and ethmoid air cells separating it from the orbit – this is why when there’s an orbital blowout fracture the orbital contents can herniate into the nasal cavity

the inferior part is made of the body of the maxilla and maxillary sinus

Question 17

what are conchae?

Answer 17

on the lateral wall of the nasal cavity there are three shelf-like bony projections called conchae: superior, middle and inferior conchae

the space deep to the each concha is called the meatus; there’s a superior, middle and inferior

then, the space above the superior concha is called sphenoethmoidal recess

Question 18

what is the function of conchae?

Answer 18

nasal conchae greatly increase the surface area of the nasal cavity and increase air turbulence, slowing down air movement which gives the air time to get warmer and more time for the dust and particles to stick to the respiratory mucous

inflammation of the mucosa may cause blockage of the air flow and nasal stuffiness

the lamina propria of the mucosa covering the conchae is highly vascular (cavernous tissue)

Question 19

what are the features of the lateral wall of the nasal cavity?

Answer 19

1. there is an opening of the posterior ethmoidal cells into the lateral wall of the nasal cavity in the superior meatus
2. in middle meatus, the middle ethmoidal air cells bulge to form the bulla ethmoidalis

the cleft deep to the bulla ethmoidalis is called hiatus semilunaris –> there’s a big opening for the maxillary sinus here

the anterior wide part of the hiatus semilunaris is called infundibulum and it drains the frontal sinus and anterior ethmoidal cells

3. in the inferior meatus there is the opening of the nasolacrimal duct

slide 14

Question 20

what is the function of the nasolacrimal duct?

Answer 20

tears end up in the nasolacrimal duct in the inferior meatus of the nasal cavity and that’s why you get a runny nose when you’re crying!

Question 21

what are all the spaces and openings in the lateral wall of the nasal cavity?

Answer 21

Sphenoid air cells: Opens into sphenoethmoidal recess

Posterior ethmoidal air cell: Opens into superior meatus

Frontal sinus: Opens into Infundibulum

Anterior ethmoidal cells: Opens into Infundibulum

Middle ethmoidal sinus: Opens into bulla ethmoidalis

Maxillary sinus: Opens in the middle of the hiatus semilunaris

Nasolacrimal duct: Opens into inferior meatus

Question 22

what are paranasal sinuses?

Answer 22

air spaces within the cranial bones surrounding the nasal cavity —> frontal, ethmoid, maxillary, and sphenoid sinuses

we don’t know their exact function but we think they increase resonance of sound and make the skull bone bigger but without a corresponding increase in weight = lighter skull!

all the sinuses open into the lateral wall of the nasal cavity and they have mucosa that’s continuous with the respiratory mucosa of the nasal cavity –> this allows for equilibration of air and mucous movement

Question 23

where is the frontal sinus located?

Answer 23

located in the frontal bone behind superciliary ridges and may extend for variable distances in the orbital plate of frontal bone

the fontal sinus opens by frontonasal ducts into the infundibulum of the hiatus semilunaris

Question 24

where is the ethmoid sinus located?

Answer 24

It forms the upper part of the lateral wall of the nasal cavity and the medial wall of the orbit

it’s located in the ethmoid bones and divided into three groups of air cells; anterior, middle and posterior

the anterior opens into the infundibulum, the middle opens into the bulla ethmoidalis, and the posterior opens into the superior recess

Question 25

what do you have to be careful of with the ethmoidal sinus?

Answer 25

it’s a very weak bone so when there are orbital blowout fractures the orbital contents could leak through fractured ethmoid into the nasal cavity

also, infection in the ethmoidal sinus can spread to the orbit, resulting into orbital cellulitis

they could lose their vision or it could kill them

Question 26

where is the sphenoid sinus located ?

Answer 26

it’s located within the body of the sphenoid bone superior to the optic chiasma and pituitary gland

it opens into the sphenoethmoidal recess

on either side the sphenoid sinus is the cavernous sinus and internal carotid arteries

Question 27

what is the clinical use of the sphenoid sinus?

Answer 27

the nasal cavity and sphenoid air sinus provide an easy access to surgically operate on the pituitary gland

Question 28

where is the maxillary sinus located?

Answer 28

it’s the largest sinus and occupies most of the body of the maxilla

the maxillary sinus opens in the middle of the hiatus semilunaris

its roof of the maxillary sinus forms the major part of the floor of the orbit and is related to the infraorbital nerve and artery

the floor of the maxillary sinus is made of hard palate and related to the alveolar arch of maxilla and molar maxillary teeth

Question 29

what do you have to be careful of with the maxillary sinus?

Answer 29

infection of maxillary sinus is common from spread of infection from the nose or maxillary teeth

chronic infection is common due to poor drainage because the opening of the maxillary sinus at the hiatus semilunaris is higher than the floor of the sinus

normally when you blow your nose you create a vacuum that helps suck stuff out of the maxillary sinus

Question 30

what are the two bones most often involved in blowout fractures?

Answer 30

1. ethmoid to the side

2. maxillary downwards

Question 31

what is the nerve supply of the nasal cavity?

Answer 31

the major innervation of the nasal cavity is the maxillary nerve through branches of the pterygopalatine ganglion

1. from ophthalmic (nasociliary) : anterior ethmoidal nerve
2. from maxillary: Infraorbital nerve and anterior superior alveolar
3. from pterygopalatine ganglion: nasopalatine nerve
4. olfactory nerve: axons of the olfactory receptor cells

Question 32

what is the blood supply of the nasal cavity?

Answer 32

majority of the blood supply is maxillary artery

1. from the maxillary artery = sphenopalatine artery, terminal part of the greater palatine artery
2. from the ophthalmic artery = anterior ethmoidal
3. from the facial artery = septal branch of superior labial of the facial

all of these branches anastamost in the lower part of the nasal septum called the Little’s area or Kiesselbach area; this is a common area of epistaxis!

Question 33

where does epistaxis come from?

Answer 33

bleeding from the nose is called epistaxis

the common site of bleeding is Little’s area/Kieselback’s area

the main culprit is usually the sphenopalatine artery

Question 34

where is the larynx located?

Answer 34

the larynx is located in the neck, extending from the root of the tongue to the trachea

it lies anterior to the vertebral column, extending from the 3rd to 6th cervical vertebrae

Question 35

what are the functions of the larynx?

Answer 35

the larynx is the beginning of lower respiratory system and serves as:

1. an air passage
2. an important sphincter, preventing food and fluids from passing into the respiratory system
3. an organ of phonation

Question 36

what is located anterior, lateral and posterior to the larynx?

Answer 36

ANTERIORLY: it’s covered by infrahyoid muscles, – except at the midline where the laryngeal prominence made by the angle of thyroid cartilage which is subcutaneous and is clearly visible and palpable, especially in males (Adam’s apple)

LATERALLY:
the apices of the lobes of the thyroid glands and the great vessels of the neck (common carotid and internal jugular vein)

POSTERIOR:
the laryngopharynx where it forms the anterior wall of the laryngopharynx

Question 37

what are the anitomical components of the larynx?

Answer 37

1. cartilage network connected together by synovial joints or fibrous ligaments
2. ligaments and membranes connecting the laryngeal carriages together (instrinsic ligaments) or to other structures (extrinsic ligaments)
3. muscles that move different cartilages during respiration, swallowing, cough, sneezing and phonation

Question 38

what are the 4 cartilages of the larynx?

Answer 38

1. cricoid (single)
2. arytenoid (paired)
3. thyroid (single)
4. epiglottis (single)

top to bottom: epiglottic, thyroid, arytenoid, cricoid

Question 39

what is the cricoid cartilage?

Answer 39

the cricoid cartilage is the skeletal foundation of the larynx and is the most fixed cartilage;; all other cartilages move around it!

it’s the only cartilage that forms a complete ring around the airway!

it looks like a signet ring with a broad posterior lamina and narrow anterior arch

Question 40

what does the cricoid cartilage articulate with?

Answer 40

at the top of the lamina, there are two articular facets for the articulation with the arytenoid cartilages

on the lateral surface of the lamina, there are two articular facets for articulation with the inferior horn of thyroid cartilage.

Question 41

what is the thyroid cartilage?

Answer 41

thyroid cartilage is the largest of all thyroid cartilages and is formed of two quadrilateral laminae that fuse at the midline to form the laryngeal prominence/anterior border/adam’s apple while the top is not totally fused together and this opening is the thyroid notch

the two cartilage diverge posteriorly, like an open book

the posterior borders of the laminae prolong superiorly and inferiorly to form the superior and inferior horns (cornu), respectively – looks like sticks sticking up from the sides of the laminae

the inferior horns articulate with the articular facets on the lateral surface of cricoid cartilage

Question 42

what i the adam’s apple made of?

Answer 42

the anterior border of the thyroid cartilage of the larynx = line of fission between right and left thyroid lamina

Question 43

what does the arytenoid cartilage look like?

Answer 43

the paired arytenoid cartilages are pyramidal in shape

the triangular bases of the arytenoid cartilages articulate with facets on the superior border of the cricoid cartilage (synovial joints)

the anterior angle of the base projects forward to form the vocal process, where the vocal ligaments attach posteriorly from the cricoid arch back to the vocal process of the arytenoid cartilage

the lateral angle of the base project laterally to form muscular process

Question 44

how does the arytenoid cartilage move?

Answer 44

this is the most important cartilage when it comes to function of the larynx! it articulates with the upper facets of the cricoid cartilage and spins around

if you rotate the muscular process backwards and medially, the vocal process will rotate laterally, bringing the vocal cord outwards which widens the area between the two vocal cords – if you pull the muscular process forward and medially the vocal process and vocal cords will move inward, bringing the vocal cords closer to each other –> so when you widen and narrow the opening it controls the amount of air going into the pulmonary system!

you can also pull the arytenoid cartilage outward/inward

Question 45

what is the epiglottic cartilage?

Answer 45

a thin leaf-like fibroelastic cartilage with a broad upper end and narrow lower end – most flexible because it’s rich in elastic fiber

its narrow lower end attaches to the posterior aspect of the laryngeal prominence, just below the thyroid notch, via the thyroepiglottic ligament

the upper broad end projects upward and backward behind the tongue and hyoid bone, and form part of the boundary of the laryngeal inlet

the epiglottis can move back and forth during swallowing

Question 46

what are the 3 extrinsic ligaments of the larynx?

Answer 46

extrinsic ligaments attache the different laryngeal cartilages to different structures outside the larynx

1. thyrohyoid membrane = connects the thyroid cartilage to the hyoid bone and has 2 openings for the superior laryngeal artery and internal laryngeal nerve
2. hyo-epiglottic ligament = connects the hyoid to the epiglottis
3. cricotracheal ligament = connects the lower border of the cricoid cartilage to the first ring of the trachea

Question 47

what are the 2 intrinsic ligaments of the larynx?

Answer 47

1. lateral cricothyroid ligament (cricovocal membrane/conus elasticus)
2. quadrangular membrane

Question 48

what is the rima glottidis?

Answer 48

it’s the opening between the right and left vocal cords and the right and left arytenoid cartilages

the opening is dynamic: it can narrow and dilate to control the amount of air passing to and from lower respiratory system during respiration, phonation, cough and sneezing reflexes

it is formed of two compartments

1. intermembranous part: between the vocal folds (3/5 of the anteroposterior dimension)
2. intercartilaginous part: between the two arytenoid cartilage (2/5)

Question 49

what is the quadrangular membrane?

Answer 49

an intrinsic membrane of the larynx that seals the upper compartment of the larynx

it’s attaches anteriorly to the epiglottis and the posterior surface of the angle of the thyroid cartilage; it attaches posteriorly to the arytenoid cartilage

the lower margin of this membrane is called the vestibular fold/false vocal cord

Question 50

what is the lateral cricothyroid membrane?

Answer 50

it seals the lower compartment of the larynx

it attaches to the vocal process of the arytenoid cartilage, the upper lamina of the cricoid cartilage, and posterior surface of the lower thyroid cartilage = this is your vocal cord!!!!

Question 51

what is the cricothyroid muscle?

Answer 51

one of the muscles of the larynx

it attaches inferiorly to the external surface of the cricoid arch and superiorly to the lower border of the thyroid cartilage and its inferior horn

it tilts the thyroid cartilage forward and downward increasing the tension of the vocal ligament

Question 52

what is the innervation of the cricothyroid muscle?

Answer 52

external laryngeal nerve, a branch of the superior laryngeal nerve from the vagus

Question 53

what is the origin, insertion, action and innervation of the posterior cricoarytenoid muscles?

Answer 53

origin: posterior surface of the lamina of cricoid cartilage
insertion: muscular process of the arytenoid cartilage
action: abducts vocal fold to open up rima glottides (the only abductor)
innervation: inferior laryngeal nerve, continuation of recurrent laryngeal, a branch of the vagus nerve

Question 54

what is the attachment, action and innervation of the transverse arytenoid muscle?

Answer 54

attachment: a single muscle attached between the backs of the arytenoid cartilages; so it connects one arytenoid to the other
action: pulls the arytenoid cartilage together, resulting in narrower rima glottidis = adducts the vocal cords

nerve supply: inferior laryngeal nerve

Question 55

what is the attachment, action and innervation of the oblique arytenoid muscle?

Answer 55

attachment: it extends from the muscular process of one arytenoid cartilage to the apex of the contralateral arytenoid cartilage; forms a criss cross
action: pull the arytenoid cartilages together, closing rima glottidis – it also closes the laryngeal inlet (aryepiglotticus)

nerve supply: inferior laryngeal nerve

Question 56

what is the attachment, action and innervation of the aryepiglotticus?

Answer 56

attachment: it’s the extension of the oblique arytenoid into the aryepiglottic folds
action: it closes the laryngeal inlet

nerve supply: inferior laryngeal nerve

Question 57

what is the lateral cricoarytenoid muscle?

Answer 57

small muscle, best seen in a lateral view after the lamina cricoid cartilage is removed

origin: arise from upper border of the arch of the cricoid cartilage
insertion: Inserts into the muscular process of the arytenoid cartilage
action: adducts the vocal folds (closes rima glottidis) –> lets you whisper!!

nerve supply: inferior laryngeal nerve

Question 58

what is the attachment and action of the thyroarytenoid muscle?

Answer 58

it runs between the lower half of the angle of thyroid cartilage back to the anterolateral surface of the arytenoid cartilage

actions:
it relaxes the vocal folds

innervation: inferior laryngeal nerve

Question 59

what is the vocalis?

Answer 59

the vocalis is the deep part of the thyroarytenoid muscle, some fibers attaches directly to the vocal folds

actions: the contractions of vocalis can change the local tension in different regions of the vocal fold
innervation: inferior laryngeal nerve

Question 60

what is the thyroepiglotticus?

Answer 60

a few thin fibers of the thyroarytenoid extend superiorly in the aryepiglottic fold to form the thyroepiglotticus muscle

the thyroepiglotticus closes the laryngeal inlet

innervation: inferior laryngeal nerve

Question 61

which larynx muscles alter the width of the rim glottides?

Answer 61

NARROWING
1. lateral cricoarytenoid

2. transverse arytenoid
3. oblique arytenoid (not shown))

WIDENING
1. posterior cricoarytenoid

Question 62

which larynx muscles regulate the tension in the vocal cords?

Answer 62

Increase tension = cricothyroid

decrease tension = thyro-arytenoid

decrease and increase= vocalis

Question 63

which 3 muscles control laryngeal inlet (sphincters)?

Answer 63

1. oblique arytenoids

2 arypiglotticus

3. thyroepiglotticus

Question 64

where is the laryngeal cavity located?

Answer 64

the aryngeal cavity extends from the laryngeal inlet, which opens into the pharynx, to the lower border of the cricoid cartilage where it continues with trachea

it’s divided into 3 compartments:

1. upper part (laryngeal vestibule)
2. middle part
3. lower compartment

Question 65

what is the laryngeal inlet and laryngeal sphincter?

Answer 65

the laryngeal sphincter is the entrance or adits to the laryngeal cavity

laryngeal inlet prevents food and allows air while rima glottis control air supply

it opens upward and backward to the pharynx (laryngopharynx)

it is bounded anteriorly by the upper margin of the epiglottis, laterally by the upper margins of the aryepiglottic folds and posteriorly by the interarytenoid mucosal fold

closure of the laryngeal inlet is an active process, including muscles contractions (oblique arytenoid, aryepiglottic and thyroepiglottic muscles) rather than mechanical obstruction by backward bending of the epiglottis

Question 66

what is the innervation of the larynx?

Answer 66

vagus nerve dives into:

1. superior laryngeal nerve
   external laryngeal = motor to cricothyroid muscle

internal laryngeal = sensory to the laryngeal mucosa from the inlet to as far down as the vocal folds

2. recurrent (inferior) laryngeal nerve:

motor:
to all the laryngeal muscles except cricothyroid

sensory:
to the laryngeal mucosa below the vocal fold

Question 67

what is the blood supply to the larynx?

Answer 67

branches of the superior and inferior thyroid arteries

Question 68

what are the movements and positions of the vocal folds during respiration and phonation?

Answer 68

slide 48

Question 69

what happens when there’s a complete lesion of one side of the recurrent laryngeal nerve? how are respiration and phonation effected?

Answer 69

the paralyzed cord is held in cadaveric position (midway between abduction and adduction)

1. respiration is okay because you only have a 25% reduction in the opening
2. phonation: is also okay because the intact cord compensates by over adduction and crosses the midline to produce full adduction

Question 70

what happens when there’s a partial lesion of the recurrent laryngeal nerve? how are respiration and phonation effected?

Answer 70

partial lesions usually affects the abductor more than adductors; the reason for this phenomenon is unknown–> the paralyzed cord will be adducted and sits in the midline since the abductor is knocked out

1. quiet respiration is ok, but forced respiration will be difficult because there’s a 50% reduction in the opening
2. phonation is normal since you can bring the vocal cords in close opposition

Question 71

what is the effect of bilateral complete paralysis?

Answer 71

both cords are held in midposition between abduction and adduction

quiet respiration will be okay but forced respiration will be a problem

with phonation, since you can’t bring the cords together phonation is eliminated!

Question 72

what is the effect of bilateral partial paralysis?

Answer 72

partial lesion affects the abductor more than adductors.

the two paralyzed cords will be adducted and sits in the midline, closing the glottis

1. all respiratory movements are compromised, this medical emergency that requires immediate tracheostomy
2. phonation: you can’t speak because if you can’t take deep breath you can’t speak; you use expiratory air flow to close the vocal cords and get them to vibrate to produce sound

Question 73

what is laryngeal obstruction, trauma or tracheostomy?

Answer 73

foreign body inhalation

trauma to the neck and fracture of laryngeal cartilages
Infection to the larynx

allergic reaction and accumulation of edema fluids under the loosely attached mucosa in the supraglottic compartment.

these factors may cause laryngeal obstruction of the air way and require tracheostomy

Question 74

what is a tracheotomy?

Answer 74

it is creating an air entry way in the trachea, bypassing the obstructed larynx

the common site is the second and third tracheal rings

the surface anatomy for the procedure is midway between the suprasternal and thyroid notches
a vertical skin incision is performed.
horizontal incision leaves less scar tissue.
Isthmus of thyroid gland is identified within the pretracheal facia, then divided and retracted

anterior jugular venous plexus or thyroidae ima artery running in this area may cause bleeding

Question 75

what is the heimlich maneuver?

Answer 75

abdominal thrusts is a first aid procedure used to treat upper airway obstructions by foreign objects.

Question 76

movement of which of the following muscle is most important muscle in respiratory movement of vocal folds?

A. vocalis

B. thyroarytenoid

C. posterior cricoarytenoid

D. lateral cricoarytenoid

E. cricothyroid

Answer 76

C. posterior cricoarytenoid

Question 77

foreign body in the laryngeal vestibule will evoke cough reflex. the afferent limb for this reflex is:

A. glossopharyngeal nerve

B. internal laryngeal nerve of vagus

C. inferior laryngeal nerve of vagus

D. external laryngeal nerve of vagus

E. phrenic nerve

Answer 77

B. internal laryngeal nerve of vagus

Question 78

foreign body in the infraglottic compartment of the laryngeal cavity will evoke cough reflex. The afferent limb for this reflex is:

A. glossopharyngeal nerve

B. internal laryngeal nerve of vagus

D. external laryngeal nerve of vagus

E. phrenic nerve

Answer 78

B. internal laryngeal nerve of vagus

Question 79

foreign body in the infraglottic compartment of the laryngeal cavity will evoke cough reflex which requires coordinated effort of which of the following combination of nerves?

A. glossopharyngeal and spinal accessory nerves

B. internal and external laryngeal nerves

C. inferior laryngeal and internal laryngeal nerves

D. external laryngeal glossopharyngeal nerves

E. phrenic and inferior laryngeal nerves

Answer 79

E. phrenic and inferior laryngeal nerves

Question 80

which of the following laryngeal muscles is NOT involved in phonation?

A. cricothyroid

B. lateral cricoarytenoid

C. posterior cricoarytenoid

D. cricothyroid

E. aryepiglotticus

Answer 80

C. posterior cricoarytenoid

Question 81

irritation of nasal mucosa evokes sneezing reflex. The afferent information of this reflex is most likely carried by which of the following nerve?

A. glossopharyngeal

B. vagus

C. maxillary nerve

D. mandibular

E. none of the above

Answer 81

C. maxillary nerve

Question 82

chronic sinusitis is a common sequala of upper respiratory tract infection. The maxillary sinus is the most frequently chronically infected paranasal sinus because of:

A. it is the largest paranasal sinus

B. it is the farthest from the nasal cavity

C. poor blood supply

D. unusually thick mucosa

E. poor drainage of mucous and suppurative materials

Answer 82

E. poor drainage of mucous and suppurative materials

Question 83

which paranasal sinus of the following provide an easy access for removal of pituitary tumor?

A. maxillary

B. posterior ethmoidal

C. sphenoid

D. frontal

E. middle ethmoidal

Answer 83

C. sphenoid

Question 84

the image on the right indicates paralysis of which of the following nerves?

A. complete lesion of the Rt. recurrent laryngeal nerve

B. partial lesion of the Rt. recurrent laryngeal nerve

C. Partial lesion of the Lt. recurrent laryngeal nerve

D. Complete lesion of Lt. recurrent laryngeal nerve

E. Complete lesion of the external laryngeal nerve

Answer 84

A. complete lesion of the Rt. recurrent laryngeal nerve

Question 85

what is the aryepiglottic fold?

Answer 85

it’s the quadrangular membrane surrounding by the mucosa of the larynx, aryepiglotticus, and thyroepigloticus