Thyroid Gland, External and internal pharynx and Larynx Flashcards
What is directly embedded on the posterior surface of the of the lateral lobes of the thyroid gland?
Parathyroid glands
What is the thyroid gland covered by anteriorly?
infrahyoid muscles
What are the two lateral lobes of the thyroid gland connected by?
Isthmus
how many lobes does the thyroid gland have?
two with a small projection sometimes called the pyramidal lobe above it
what is the blood supply of the thyroid gland?
the superior (branch of external carotid) and inferior thyroid arteries. The inferior thyroid artery also supplies the parathyroid glands
What is the drainage of the thyroid gland?
superior and inferior thyroid veins
What pathology related to the thyroid gland could cause hoarseness of voice in a patient?
a malignant tumour of the thyroid gland could compress the recurrent laryngeal nerve affecting movement of the vocal cords and therefore causing hoarseness of voice.
The nerve is also prone to damage during surgery because it is in close relation to the inferior thyroid artery.
At what level does the pharynx open into the oesophagus?
at the level of the cricoid cartilage
What is the interior of the pharynx divided into?
nasopharynx (continuous of the nasal cavity), oropharynx (continuous of the oral cavity) and hypopharynx (laryngopharynx)
What are the constricter muscles on the walls of the pharynx called?
superior constricter, middle constricter and inferior constricter
At what point do all the constricter muscles fuse together?
at a midline raphe on the posterior aspect of the pharynx.
where does the stylopharyngeus muscle lie?
between the internal and external carotid arteries to reach the interval between the superior and middle constricter muscles
Which nerve lies on the surface of the stylopharyngeus muscle as it enters the pharynx?
glossopharyngeal nerve (CN IX)
What does the glossopharyngeal nerve innervate?
sensory innervation to the posterior third of the tongue and oropharynx and also supplies the stylopharyngeus muscle. It also has a tympanic branch which supplies the middle ear and the auditory (eustachian) tube.
What are the three major branches of the vagus in the neck?
Pharyngeal nerve, Superior laryngeal nerve and recurrent laryngeal nerve
What does the pharyngeal nerve innervate?
motor to muscles of the pharynx and to the soft palate
Where does the superior laryngeal lie and what does it innervate?
lies deep to the internal and external carotid arteries. It divides into the internal and external laryngeal nerves
What does the internal laryngeal nerve innervate?
supplies sensory fibres of the laryngeal mucosa
What does the external laryngeal nerve innervate?
cricothyroid muscles as well as part of the inferior constricter
What are the branches of the recurrent laryngeal nerve?
right and left recurrent laryngeal nerve
What does the recurrent laryngeal nerve innervate?
sensory mucosa below vocal cords and the motor muscles of the larynx
what is the path of the left recurrent laryngeal nerve from it branching off the vagus?
It lies in the groove between the trachea and oesophagus on the left side it then loops below the aorta (arch) and winds around the ligamentum arteriosum in the thorax
What is the path of the right recurrent larygneal nerve?
branches off the right vagus and winds around the subclavian artery. It lies in the groove between the trachea and oesophagus and runs upwards until it disappears under the lower border of the inferior constricter.
What does the superior laryngeal nerve innervate?
sensory (mucosa) above vocal cords via internal layngeal. cricothyroid muscle.
where does the opening of the eustachian tube lie and why is it clinically significant?
in the nasopharynx. The eustachian tube can be blocked by enlargement of adenoids in throat infections, infections from here can also spread to the middle ear. An early sign of a malignant tumour in the nasopharynx may be deafness due to blockage of the auditory tube.
What is the main sensory innervation of the oropharynx?
glossopharyngeal nerve (CN IX)
What artery mainly supplies the tonsils?
facial artery
A forward extension of the hypopharynx forms a ‘cul de sac’ by the side of the larynx. What is this called?
piriform fossa: malignant tumours aising here are ‘silent’ in early stages
What is the main innervation of the hypopharynx?
internal laryngeal nerve
The Larynx is held open by cartilages on its wall, what six cartilages make up this structure?
cricoid cartilage, thyroid cartilage, epiglottis, arytenoid cartilage, corniculate cartilage, cuneiform cartilage
Where does the larynx begin and end?
begins at vertebra C4 or C5 and ends at C6
what are the two folds of mucosa in the larynx called?
superior vestibular folds (false vocal cords) and inferior ‘true’ vocal folds
What are the three main muscles of the larynx?
cricothyroid muscle, cricoarytenoid, thyroarytenoid
What does the cricothyroid do?
it approximates the thyroid and cricoid cartilages anteriorly, increasing the distance between the attachments of the cords. Lengthening them.
which nerve innervates (motor) all the internal muscles of the larynx except the cricothyroid?
recurrent laryngeal nerve
which nerve innervates the cricothyroid muscle (motor)?
external laryngeal branch of the superior laryngeal nerve
what is the blood supply to the larynx?
superior and inferior laryngeal arteries
Which nerve does sensory innervation below the vocal cords?
recurrent laryngeal nerve
Which nerve does sensory innervation above the vocal cords?
internal laryngeal nerve
What are the three main salivary glands in the face and neck?
submandibular gland, parotid gland and sublingual gland
Where is the submandibular gland located and where opening of its duct in the mouth?
floor of the mouth, gives off a duct which opens into the floor of the mouth under the tongue
where is the parotid gland located and which nerve travels through it?
posterior to the submandibular gland, just under the skin in front of the external ear. The facial nerve runs through it to supply the muscles of the face.
where in the mouth is the opening of the duct for the parotid gland?
inner surface of the cheek, adjacent to the second molar
How many branches does the facial nerve divide into in the parotid gland?
five branches
What are the branches of the facial nerve called?
temporal, zygomatic, buccal, mandibular, cervical
what is the vagus parasympathetic outflow?
cranial nerves 3, 7, 9 and 10
what is the vagus sympathetic chain?
T1-L2
What does the facial nerve innervate?
taste to the anterior 2 thirds of the tongue, facial muscles, parasympathetic to submadibular and sublingual glands. Also innervates the stapedius muscle in the ear.
How would you check for injury of the facial nerve?
scrunch face-facial slumping, taste, loud noise in ear
what does the glossopharyngeal nerve innervate and how would you test it?
taste to posterior two thirds of the tongue, parasympathetic to the parotid gland, sensory to the pharynx. Check gag reflex and swallowing function
What does the parasympathetic of the vagus do?
motor to muscles of the larynx, sensory muscose above vocal cords via superior laryngeal and sensory to mucosa below vocal cords- recurrent laryngeal. Check- gag reflex
What does the hypoglossal do and how would you test it?
muscles of the tongue, sticking out tongue
What does the oculomotor nerve do and how would you test it?
innervates muscles that enable most movements of the eye and that raise the eyelid. check by following finger with eyes
describe the movements in the throat when swallowing
larynx elevated and epiglottis folds back over the glottis, preventing both liquids and solid food from entering the respiratory tract