Anatomy of the Upper Respiratory Tract

Question 1

what is the clinical significance of the larynx?

Answer 1

larynx sits below nasal + oral cavity and in front of the laryngeal pharynx

*larynx connects upper and lower airway (between pharynx and trachea)

*location of the larynx is at the level of the C3 to C6 vertebrae and is held into position by muscles and ligaments. The superior-most region of the larynx is the epiglottis, which is attached to the hyoid bone connected to the inferior part of the pharynx

function of larynx:
phonation
cough reflex
protection of lower airway

Question 2

what makes up the upper respiratory tract

Answer 2

upper respiratory tract= everything above the trachea; nasal cavity, nostrils, oral cavity, pharynx (throat) + larynx (voicebox)

Question 3

where do the paranasal sinuses drain?

Answer 3

The paranasal sinuses drain into the nasal cavity at the hiatus semilunaris, underneath the frontal sinus opening.

n.b. This is a potential pathway for spread of infection - fluid draining from the frontal sinus can enter the maxillary sinus

Question 4

what conchae are found projecting off ethmoid bone

*what is the function of conchae

Answer 4

The superior concha and middle nasal concha are medial bony projections of the ethmoid bone.

*nasal conchae are curved folds of bone aka nasal turbinates
*nasal meatuses are nasal passages beneath the conchae (these are covered by ciliated respiratory epithelium; pseudostratified columnar)
*function of conchae is to increase the surface area (SA) of nasal cavity

Question 4

which cranial nerve passes through cribiform plate?

Answer 4

Olfactory nerve (CN I) fibers travel a short distance to an area in the upper part of your nose (olfactory bulb). Before reaching your olfactory bulb, the nerve fibers pass through your cribriform plate. This spongy, lightweight skull bone separates your nasal area from your brain

Question 5

the nose has general sensory innervation (e.g. pain,sensation) and special sensation (smell) which nerves are responsible for this

Answer 5

CN I OLFACTORY nerve= special sensory; smell

CN V1 opthalmic division of trigeminal nerve (nasociliary nerve)= general sensory innervation

CN V2 maxillary division of tirgeminal nerve (nasopalatine nerve)= general sensory innervation

Question 6

what is waldeyer’s ring of lymphoid tissues

Answer 6

Waldeyer’s tonsillar ring includes the lymphoid tissues (tonsils) of the nasopharynx, tonsils, and base of the tongue

*pharyngeal tonsil
*tubal tonsils
*palatine tonsils
*lingual tonsils

Question 7

the pharynx is made up of 3 regions explain them;

Answer 7

nasopharynx
*base of skull to soft palate
*behind nasal cavity
*sensory: CN V2 (maxillary branch of trigeminal nerve)

oropharynx
*soft palate to epiglottis
*behind oral cavity
*sensory: CN IX (glossopharyngeal)

laryngopharynx
*epiglottis to inferior border or cricoid (behind larynx)
*continuous with oesophagus
*sensory: CN X (vagus)

Question 8

what cranial nerves supply the following
*stylopharyngeus
*superior constrictor
*palatopharyngeus
*inferior constrictor
*middle constrictor

Answer 8

*stylopharyngeus= only supplied by CN IX (glossopharyngeal)

all remainder supplied by CN X (vagus)
*superior constrictor
*palatopharyngeus
*inferior constrictor
*middle constrictor

Question 9

what is the function of the epiglottis

Answer 9

epiglottis= flattens and closes over laryngeal inlet during swallowing to prevent aspiration into trachea

Question 10

name the cartillages of the larynx: unpaired and paired

Answer 10

3 unpaired:
*epiglottis cartillage
*thyroid cartilllage {adams apple}
*cricoid cartillage

3 paired:
*arytenoid cartillage
*corniculate cartillage
*cuneiform cartillage (anterior to corniculate)

Question 11

what is a cricothyroidotomy?

Answer 11

cricothyroidotomy= an emergency airway (docs makes incision so patient can breathe)

*laryngeal prominence of thyroid cartillage (aka adams apple)
*inferior to adam’s apple= cricoid cartillage

IN BETWEEN THESE IS CRICOTHYROID LIGAMENT; SITE OF THE EMERGENCY AIRWAY

Question 12

which muscle elevates the larynx, and which one depresses the larynx

Answer 12

elevation of larynx= suprahyoid group (digastric,mylohyoid,stylohyoid, geniohyoid)

depression of larynx=
infrahyoid group (thyrohyoid,omohyoid,sternohyoid, omohyoid, sternothyroid)

Question 13

the larynx (voicebox)= involved with swallowing, breathing and voice production. It is made up of the following structures, can u list their functions:

*vestibular folds
*rima vestibuli
*vocal folds (vocal cords)
*rima glottidis
*glottis

Answer 13

vestibular folds= mucuous membranes encasing vestibular ligaments; protective function

rima vestibuli= space between vestibular ligaments

vocal folds (vocal cords)= mucuous membranes encasing vocal ligaments

rima glottidis= space between vocal ligaments

glottis= vocal apparatus of larynx including vocal folds, ligament and rima glottidis

Question 14

what nerves innervate the following intrinsic laryngeal muscles:

*cricothyroid

*thyroarytenoid
*posterior cricoarytenoid
*lateral cricoarytenoid
*transverse arytenoid
*oblique arytenoid

Answer 14

*cricothyroid= innervated by external branch of the superior laryngeal nerve (vagus CN X)

the rest are innervated by the inferior laryngeal nerve- terminal branch of the recurrent laryngeal nerve (vagus CN X)
*thyroarytenoid
*posterior cricoarytenoid
*lateral cricoarytenoid
*transverse arytenoid
*oblique arytenoid

Question 15

which nerve is responsible for PITCH and which nerve is responsible for PHONATION

Answer 15

PITCH:
external laryngeal nerve (branch of superior laryngeal nerve of CN X vagus) it is also the motor to cricothyroid muscle

PHONATION:
recurrent laryngeal nerve(branch of CN X vagus) MOTOR to all intrinsic muscles EXCEPT cricothyroid. Also sensory innervation to area below vocal cords

Question 16

sensory innervation above the vocal cords is supplied by which nerve

Answer 16

internal laryngeal nerve (is a branch of the superior laryngeal nerve) it provides sensory innervation to area above vocal cords