CVR 8 Flashcards
Which nerve innervates most of the intrinsic muscles of the larynx?
The right and left recurrent laryngeal nerves innervate all the intrinsic muscles except cricothyroid.
Explain why hoarseness or a change in the quality of the voice might indicate that a patient has lung cancer.
Because it travels through the thorax, malignancy of the left lung may involve the left recurrent laryngeal nerve. The left recurrent laryngeal nerve innervates all the intrinsic muscles on the left side of the larynx, except for cricothyroid. If the intrinsic muscles on the left side of the larynx are weak or paralysed, the left vocal fold cannot move, and this affects the quality of the voice.
A patient develops weakness of the right side of their face after surgery on their right parotid gland – what has happened?
The facial nerve travels through the parotid gland. Injury to the facial nerve is a known risk in parotid surgery that patient’s must be informed of prior to surgery. The facial nerve separates into five branches as it travels through the gland. Injury to individual branches leads to weakness or paralysis of the facial muscles
innervated by that branch. Injury to the facial nerve proximal to these divisions results in weakness / paralysis of all the facial muscles on the ipsilateral side of the face.
Where do the parotid and submandibular ducts enter the mouth?
- Parotid - from the inner cheek adjacent to the second upper premolar.
- Submandibular - under the tongue.
After an endotracheal tube is passed through the vocal cords, how can the anaesthetist be sure that the tip of the tube is in the trachea? Where might the tube be instead?
An endotracheal tube is passed into the trachea for ventilation. A laryngoscope is used to directly visualise the vocal cords and the tube passing between them. However, the tube may be incorrectly placed into the oesophagus, or the tube may be advanced too far into one of the bronchi (and so only one lung will be
ventilated). Correct placement into the trachea is confirmed by a carbon dioxide reading on the anaesthetic machine (expired air from the patient) and auscultating both lungs to ensure the tube is in the trachea and not one of the bronchi
