Anatomy of the Larynx Flashcards
Describe the blood supply to the medial and lateral walls of the nasal cavity?
Anterior and posterior ethmoidal (from the ophthalmic artery), sphenopalatine and greater palatine arteries (from the maxillary artery) and the septal branch of the superior labial artery (from the facial artery)
Name the five arteries that supply the nasal cavity
Anterior ethmoidal, posterior ethmoidal, sphenopalatine, greater palatine and septal bench of the superior labial artery
What are air sinuses?
Paranasal sinuses are air-filled extensions of the respiratory part of the nasal cavity connected by small openings into the cavity
What is the purpose of nasal air sinuses?
The mucosa of the sinuses helps to warm and humidify the air as it comes in. The air sinuses also aid in lightening the skull and enhancing vocal resonance
What are the four main types of nasal air sinus?
Frontal, maxillary, sphenoid and ethmoid air cells
Which three structures make up the nasal septum?
Anterior = septal cartilage Superior = perpendicular plate of ethmoid bone Inferior/posterior = vomer bone
What are nasal conchae?
Long, narrow, curled shelf of bone that protrudes into the breathing passage of the nose
Define epistaxis
Bleeding from the nose
What is Kiesselbach’s plexus? What is it’s clinical significance?
The region in the anteroinferior part of the nasal septum where all of the arteries supplying the nasal cavity anastomose to form a vascular plexus
What is sinusitis?
Where the linings of the sinuses become inflamed
Name the four different types of tonsil
Adenoid (pharyngeal tonsil), tubal tonsil, palatine tonsil and lingual tonsil
Where are the adenoids located (pharyngeal tonsil)?
In the roof of the pharynx
Define tonsil
Tonsils are collections of lymphoid tissue facing into the aerodigestive tract.
Where are the tubal tonsils located?
In the roof of the pharynx
Where are the palatine tonsils located?
At the sides of oropharynx between palatoglossal
and palatopharyngeal arches
Where is the lingual tonsil located?
Behind terminal sulcus (tongue)
What is the blood supply to the palatine tonsil
Blood supply is provided by tonsillar branches of five arteries:
> dorsal lingual artery
> ascending palatine artery
> descending palatine artery
> tonsillar branch (of the facial artery)
> ascending pharyngeal artery
What is the function of tonsils?
These immunocompetent tissues are the immune system’s first line of defense against ingested or inhaled foreign pathogens
What is quincy?
Peritonsillar abscess; a collection of pus forms between one of your tonsils and the wall of your throat
What may cause quincy?
Tonsillitis ; a bacterial infection can spread from the infected tonsil to the surrounding area
What are the three sections of the pharynx?
Nasopharynx, oropharynx and laryngopharynx
What is the sensory supply to the pharynx?
Glossopharyngeal (CN IX) from the pharyngeal plexus
What is the motor supply to the pharynx?
Vagus nerve (CN X) from the pharyngeal plexus
Which nerve is the motor in the gag reflex?
Vagus (CN X) as it’s the motor to the pharynx
Describe the cartilaginous and bony structures of the pharynx
Superiorly is the hyoid bone (floating), followed by the thyroid cartilage, the laryngeal prominence (adam’s apple) and then the cricoid cartilage. Thereafter is the tracheal rings.
Where is the hyoid cartilage found?
At T3
What is the Adam’s apple?
It is the laryngeal prominence of the thyroid cartilage
Where is the cricoid cartilage found?
At C6, the junction of the pharynx, oesophagus and larynx
How many cartilaginous structures are there in the larynx?
9; 3 paired and 3 unpaired
Name the cartilages of the larynx
Unpaired: epiglottis, cricoid and thyroid cartilage
Paired: arytenoid, cuneform and corniculate cartilage
What are the vocal folds?
Sharp-edged folds of mucous membrane that contain vocal ligament and vocalis muscle
Name the two extrinsic muscles of the larynx
Infrahyoid and suprahyoid
What is the function of the extrinsic muscles of the larynx?
To elevate and depress the larynx
What is the role of cricothyroid?
Cricothyroid is a muscle that can pull the thyroid cartilage down to increase the distance so that the folds tighten and you get an increased pitch
What is the function of the intrinsic relaxer muscles of the larynx?
Lower the pitch of your voice by pulling the arytenoid cartilage anteriorly
What is the role of the adductors and adbuctors of the intrinsic laryngeal muscles?
Open and close the rima glottidis by rotating the adenoids
What is the nerve supply to the cricothyroid muscle?
External laryngeal nerve
Which nerve provides the visceral afferents for the cough reflex?
Internal laryngeal nerve
What is the motor nerve supply to the intrinsic muscles of the larynx
Recurrent laryngeal nerve
Define phonation
The production of speech
Which nerve is involved in phonation?D
Recurrent laryngeal nerve
Which nerve is involved in pitch?
External laryngeal nerve (branch of the vagus via the superior laryngeal nerve)
What would happen if there was injury to the superior laryngeal nerve?
This here supplies sensory branches for the choking reflex (internal) and motor to the cricothyroid which regulates pitch (external) so damage could cause loss of the choking reflex and lead to monotonous voice
What would happen if there was injury to the recurrent laryngeal nerve?
The recurrent laryngeal nerve supplies all of the internal laryngeal muscles which are involved in phonation therefore damage can lead to hoarseness
What structures travel in the carotid sheath?
Common carotid artery (and internal carotid), internal jugular vein, vagus nerve and deep cervical lymph nodes
How does the body respond to the aspiration of foreign bodies?
If there is a foreign object in the vestibule then the laryngeal muscles will go into spasm and the rima glottidis will close. Air will remain in the lungs, so the Heimlich manoeuvre is used inferior to the sternum to increase abdominal pressure and force the ejection of the foreign body.
