Upper airway Flashcards
Where does the eustachian tube connect to from the ear?
Into the nasopharynx
What sticks into the nasal cavity
Turbinate bones
What is conchae. What type of epithelium in the nose
Turbinate bone + soft tissue. Covered in respiratory epithelium
ciliated psudeostratified epithelium, interspersed with mucus-secreting goblet cells.
How many conchae
3 (sup. mid. inf.)
What are the sup. mid and inf meatuses of the nasal cavty
spaces between the protruding conchae
Sup= between superor and middle conchae etc.
Function of conchae
Warm and humidify air, help trap pathogens
Learn the bones of the nose
Learn
Innervation to the nasal cavtiy
Olfactory nerve (I)- olfaction
Trigeminal nerve (V1 for anterior and V2 for posterior region)
Facial nerve- glands (i.e. nasolacrimal glands)
Sympathetic nerves from T1 for vascular smooth muscle
Blood supply of nasal cavity
Branches of the internal carotid and the external carotid
INTERNAL: anterior and posterior ethmoidal arteries (branches of opthalmic)… they descend into nasal cavity through cribiform
EXTERNAL: Sphenopalatine artery Greater palatine artery Superior labial artery Lateral nasal arteries
they form anastomoses
Venous drainage of nasal cavity
Top part drains into the cranial cavity
rain into the pterygoid plexus, facial vein or cavernous sinus.
Innervation of the different sinuses
Frontal- V1 (this is located where you touch for cranial nerve V1!)
Ethmoidal air cells (=sinus but like honeycomb)- V1&2
Sphenoid- V1&2
Maxillar- V2 (think this is where you touch to test for cranial nerve V2!)
How do sinuses appear on x-ray
Dark
Where do the sinuses drain
Into the meatuses between conchae
Where do following sinuses drain into the nasal cavity:
-Frontal
-Ethmoidal
-Sphenoid
-Maxilary
Also nasolacrimal duct & Eustachian tube
Frontal & Anterior ethmoidal cells = infundibulum opening of semilunar hiatus of middle meatus (lateral wall) via frontonasal duct
Middle ethmoidal cells = ethmoidal bulla above semilunar hiatus of middle meatus (lateral wall)
Posterior ethmoidal cells = superior meatus (lateral wall)
Sphenoid sinus = spheno-ethmoidal recess of posterior roof of nasal cavity
Maxillary sinus = floor opening of semilunar hiatus of middle meatus (lateral wall)
Nasolacrimal duct = inferior meatus
Eustachian tube = nasopharynx (level of inf concha)
What is the larynx made of
cartilage, membrane and muscles
Function of larynx
VALVE and sound produceer
Where does the hyoid bone lie
Between the mandible and the thyroid cartilage
What membrane lies beneath the thyroid cartilage and cricoid cartilage
cricothyoid membrane
T/F the cricoid is larger anteriorly
F is it larger posteriorly
How is the tension on the vocal folds controlled
By muscle and by the thyroid cartilage rocking on the cricoid cartilage
State a case when the larynx is completely open, completely closed off and partially open
Open- breathing
Closed- swallowing
Partially open- to speak (create tension on vocal fold
What do the vocal folds attach to
Arytenoid cartilage (they can be moved by muscle to open or close the airway)
What is the name of the join on which the thyroid cartilage rocks
Cricothyroid joint (between the inferior horn of thyroid cartilage and the large posterior part of the cricoid)
Where do the arytenoid cartilages lie
What is their shape
What structures connect them with the inner side thyroid cartilage
On top of the posterior part of the cricoid cartilage
Pyramidal shape
Vestibular ligaments from anterior sup side of ary
Vocal ligaments from anterior inferior edge of ary
Function of the ligaments vs folds in the larynx
Ligament- support cartilaginous skeleton
Folds- airway protection and phonation
List the extrinsic muscles of the larynx
Supra and infra hyoid muscles.
Supra hyoid tend to elevate the larynx while infrahyoid tend to depress it.
Suprahyoid: Mylohyoid, anterior and posterior belly of digastric, geniohyoid and stylohyoid
Infrahyoid: strap muscles: sternohyoid, sternothyroid, thyrohyoid and omohyoid (superior and inferior belly)
List the instrinsic muscles of the larynx
Cricothyroid
Thyroarytenoid (thyroid - arytenoid cartilage) - sphincter of laryngeal inlet
Posterior cricoarytenoid (ridge of posterior surface of cricoid - arytenoid cartilage) - ext rotate arytenoid cartilages + abduct vocal cords = open rima glottidis
Lateral cricoarytenoid (lateral side of cricoid - arytenoid cartilage) - int rotate ary cartilage + adduct vocal cords
Transverse arytenoid (between arytenoid cartilages) - adduct arytenoid cartilages
Oblique arytenoids (X between arytenoid cartilages) - sphincter of laryngeal inlet
Function of cricothyroid muscle and attachment
Rocks thyroid cartilage forward stretching vocal cords….
TENSOR of vocal cords
Increase pitch
Attached to anterolateral cricoid and inferior horn of the thyroid
Function of thyroarytenoid muscle
Rocks thyroid cartilage back allowing vocal cords slack…. RELAXOR of vocal cords
Decrease pitch
Attached to posterior aspect of thyroid cartilage and anterolateral part of arytenoid
Function of posterior cricoarytenoid muscle
Rotates arytenoid laterally, allows vocal cords to ABDUCT (move apart)
Attaches to posterior part of cricoid and the musclar process of the arytenoid
Function of lateral crycoarytenoid muscle
Rotates arytenoid medially, allows vocal cord to ADDUCT (move together)
Attaches to arch of cricoid and muscular process of arytenoid
Function of transeverse and oblique arytenoid muscles
Adduct the vocal cords, closing posterior portion of the rima glottidis… narrows laryngeal inlet
Spans between arytenoids
What is the nerve supply of the intrinsic muscles of the larynx
All supplied by the recurrent laryngeal nerve (branch of the vagus nerve)
Apart from cricothyroid. muscle (tensor) which is supplied by the external branch of the superior laryngeal nerve (also a branch of the vagus)
State the divisions of superior laryngeal nerve
So from vagus you have superior and recurrent laryngeal
Superior splits into internal and external laryngeal nerve.
Internal: sensory innervation above the vocal folds
External: Motor innervation to cricothyroid
Outline sensory supply to the larynx
Above vocal folds: internal laryngeal nerve
Below vocal folds: recurrent larygneal nerve
Consequences of lesions to:
- vagus
- internal laryngeal
- external larngeal
- Recurrent laryngeal
Look at diagram
When could there be a lesion of the recurrent laryngela nerve
During thyroid surgery
Or left bronchial or oesophageal tumour/swollen mediastinal lymph nodes
Differentiate course of left and right laryngeal nerve
Obvious
Outline possible routes of infection into the cranial cavity
Infection of teeth of upper jaw can spread to maxillary sinus and cranial cavity
Infection of the middle ear can spread to mastoid air cells and cranial cavity
What is the clinical relevance of the sphenoid sinus
It must be passed through in a transsphenoidal approach to pituitary surgery (pituitary gland lies right behind it)
Differentitate the anatomical positions for emergency cricothyroidotomy vs tracheotomy
Cricothyroidotomy done in emergency…. between thyroid (sup.) and cricoid (inf) so through the cricothyroid membrane
Trachemotomy done below both strucutres into the trachea not larynx
Outline the course of the superior laryngeal nerve and the recurrent LN
Superior travels with superior thyroid artery (1st branch of external carotid)
Recurrent travels with inferior thyroid artery (from thyrocervical trunk of the subclavian artery)
Learn anatomy of external ear
Concha of aurice
State the protective mechanisms of the airway
Swallowing
Gag reflex
Coughing
Sneezing
Differenitate a cough and a sneeze
Cough= when the nasopharynx is closed off (so when the soft palate closes of nasopharynx)
Sneeze= when oropharnx close aas soft palatate depresses gainst the tongue
Differentiate the afferents leading to sneeze and cough
Sneze - V2
Cough - X
Muscles and nerves used to move soft palate in cough and sneeze
Sneeze- palatopharyngus and palatoglossus (X)
Cough (levator veli palatini (X), tensor veli palatini (V3) and superior constrictor (X)
ABDUCTION of vocal folds to increase intrathoracic pressure through nose or mouth
How can airway be managed
- Chin lift/ jaw thrust
- Oropharyngeal or nasopharyngeal airway
- Endotracheal intubation
- Cricothyroidotomy
- Tracheostomy
What is the motor function of facial nerve
Muscles of facial expression, stapedius, digastric (posterior belly), stylohyoid.
Sensory function of facial nerve (smaller)
Taste (ant 2/3 tongue), parasympathetic (lacrimal glands, mucous glands of nasal cavity, hard and soft palates, sublingual and submandibular glands) by CHORDA TYMPANI
General sensation from external acoustic meatus and deeper parts of auricle.
look at where facial nerves exit the skull base
…
Which vessels do the nerves supplying the larynx travel with
External branch of superior laryngeal: superior thyroid artery
Recurrent laryngeal: woth inferior thyroid artery
