Surgery>>>>>Thyroid, Parathyroid, and Adrenal
Question 6#

Thyroid hormones (T3 and T4) have regulatory roles in all of the following EXCEPT:

A. The hypoxia and hypercapnia drives of the respiratory center in the brain
B. Gastrointestinal motility
C. The speed of muscle contraction and relaxation
D. Visual acuity in low-light conditions ("night vision")

Correct Answer is D

Comment:

Thyroid hormones are responsible for maintaining the normal hypoxic and hypercapnic drive in the respiratory center of the brain, and regulate gastrointestinal motility which leads to diarrhea in hyperthyroidism and constipation in hypothyroidism. They also regulate bone and protein turnover and the speed of muscle contraction and regulation, hepatic gluconeogenesis, cholesterol synthesis, and intestinal glucose absorption.