Chapter 15: Thyroid and Parathyroid Surgery

Chapter 15: Thyroid and Parathyroid Surgery

Complete Chapter Questions With Answers

Sample Questions Are Posted Below

MULTIPLE CHOICE

1. The pyramidal lobe of the thyroid is described as:

ANS:  C

The pyramidal lobe, a long, thin projection of thyroid tissue protruding cephalad from the isthmus, is found in about 30% of patients at surgery; it is the vestige of the embryonic thyroglossal duct and migrates from the foramen cecum at the base of the tongue. If the migratory tract fails to degenerate, a fistula or cyst may be present.

REF:   Page 566

2. The primary function of the three thyroid hormones is to regulate:

ANS:  A

The thyroid gland produces three hormones: thyroxine (T₄) and triiodothyronine (T₃) (together known as the thyroid hormones [THs]) and calcitonin. T₃ and T₄ cannot be synthesized without iodine. Calcitonin increases calcium storage in the bone and decreases blood calcium levels. The primary function of thyroid hormones is to regulate energy metabolism, but they also play an important role in growth and development. Thyroid-stimulating hormone (TSH) is synthesized by the anterior pituitary, and stimulates the production and release of thyroid hormones and the uptake of iodine.

REF:   Page 566

3. Postoperative hoarseness, obstructed airway, or paralysis of the vocal cords is a serious complication of thyroid surgery. During surgery, care is taken to identify and protect which nerve?

ANS:  D

The recurrent laryngeal nerve, a branch of the vagus nerve, innervates the intrinsic muscles of the larynx. During surgery, care is taken to identify and protect this nerve. Immediate hoarseness occurs if the nerve is divided on one side. If the recurrent nerve is injured bilaterally, acute paralysis of both vocal cords may obstruct the airway and require emergency tracheotomy. Injury to the external branch of the superior laryngeal nerve, which innervates the cricothyroid muscle, results in difficulty shouting or singing high notes.

REF:   Page 566

4. What is the mechanism by which the parathyroid glands maintain calcium homeostasis?

ANS:  B

The parathyroid glands secrete parathyroid hormone (PTH), an antagonist to calcitonin. Both PTH and calcitonin work together to maintain calcium homeostasis by increasing

calcium removal from storage in bone and increasing absorption of calcium by the intestines.

REF:   Pages 567, 572

5. The preoperative testing regimen for diagnosing thyroid disorders follows a structured plan of history taking, neck palpation, imaging scans, and fine needle aspiration. Select the statement from that is an appropriate reflection of a thyroid diagnostic study.

ANS:  C

Ultrasonic scans evaluate thyroid nodules and are useful to determine the size and number of nodules within the thyroid as well as to monitor size progression during follow-up. In addition to palpation of the thyroid gland for size, contour, consistency, lymph nodes, fixation, tenderness, and bruits, scans are used to clarify thyroid anatomy. CT and MRI scans are used to assess a thyroid with suspected malignancy for encroachment of the tumor outside the thyroid capsule into the adjacent tissue of the neck. Scans are the most effective means to evaluate local invasion of surrounding tissue. Fine needle aspiration is usually performed under ultrasound guidance. Several samples are aspirated from various parts of the nodule.