Chapter 10. Head and Neck
Which muscle is innervated by the external branch of the superior laryngeal nerve?
A. Posterior cricoarytenoid
B. Lateral cricoarytenoid
Answer: D. The cricothyroid muscle is the only muscle of the larynx innervated by the external branch of the superior laryngeal nerve. All other laryngeal muscles are innervated by the recurrent laryngeal nerve.
A 48-year-old male with massive head trauma does not have a gag reflex. Which nerve is responsible for the sensory nerve fibers that carry this reflex?
A. Marginal mandibular nerve
B. Recurrent laryngeal nerve
D. Glossopharyngeal nerve
Answer: D. The afferent limb of the gag reflex comes from the glossopharyngeal nerve (cranial nerve IX).
The most common cause of a neck mass in males over the age of 60 is:
Answer: B. Most neck masses in males over the age of 60 are a result of metastatic spread from cancers in the chest and abdomen. These cancers frequently metastasize via lymphatic spread, and the most common location for the neck mass is within the supraclavicular fossa.
A second-year internal medicine resident stops you in the hall with a painless, 2-cm, slowly enlarging parotid mass. What does this most likely represent?
D. Mucoepidermoid carcinoma
E. Adenoid cystic carcinoma
Answer: C. Pleomorphic adenomas are the most common benign salivary gland tumors, comprising 85% of all salivary gland neoplasms. Tumors of the parotid gland are the most common of the salivary gland tumors, with a 5 times higher incidence than tumors of the minor salivary glands. The vast majority of tumors of the parotid gland are benign in nature.