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