This challenging quiz seeks to gauge your understanding of some trickier concepts in thyroid anatomy and physiology. Good luck!
Reviewed by Jonathan Loomes-Vrdoljak on 3 October 2019
Thyroid Physiology MCQs
Congratulations - you have completed Thyroid Physiology MCQs. You scored %%SCORE%% out of %%TOTAL%%. Your performance has been rated as %%RATING%%
Your answers are highlighted below.
What is the classic origin of the inferior thyroid artery?
External carotid artery
Common carotid artery
A branch of the distal subclavian artery
The thyrocervical trunk
Occlusion of which of the following structures would cause inferior thyroid vein drainage obstruction?
The external jugular vein
The internal jugular vein
The brachiocephalic trunk
The brachiocephalic vein
Which of the following is true of the superior thyroid artery?
It travels adjacent to the sensory supply of the infraglottic compartment
It supplies the cricoid cartilage
It courses around the pyramidal lobe
It arises superior to the level of C4
A consequence of calcitonin release will be ...
To increase T3 production
To decrease the basal metabolic rate
To increase NPT2A functionality
To increase circulating hormone derived from endocrine chief cells
Question 4 Explanation:
Chief cells of the parathyroid gland secrete parathyroid hormone. It has an action antagonistic to calcitonin - namely to cause a release of bone calcium (amongst other stores) and to increase serum Ca++. As calcitonin acts to sequester calcium into stores away from the serum, the resultant drop in calcium levels causes the chief cells to release PTH to compensate. Do not confuse with gastric mucosa chief cells.
A patient is to be scanned for radiolabeled iodine 24 hours after intravenous administration. Which of the following cell types will be accumulating tracer?
Oxyntic (parietal) cells
Question 5 Explanation:
The correct answer are the thyroid follicular cells. They “capture” iodide from the diet. C cells, aka parafollicular cells, primarily release calcitonin and play a negligible role in iodide sequestration. The remaining options are gastric cells, not relevant. NB: there are chief cells in the thyroid and gastrointestinal tract with different anatomy and physiology.
Iodide is “trapped” in thyroid parenchyma using which form of transport?
Question 6 Explanation:
In a secondary active transport, energy is used to transport a substance across a cell membrane. Unlike primary active transport, ATP is not directly involved, rather its metabolically-intensive process at another site causes an electrochemical gradient that is used in secondary active transport. Be familiar with the terms of membrane transport in human physiology.
Which of the following is the poorest source of iodine?
Ground black pepper
Question 7 Explanation:
Fruit, vegetables, salt and seafood are all high in dietary iodine. Indeed in landlocked regions, or areas of high altitude, deficiency of iodine is relatively common.
Pendrin’s functionality can best be described as
A symporter on the apical parafollicular cell membrane
An antiporter on the apical parafollicular cell membrane
A symporter on the apical follicular cell membrane
An antiporter on the basolateral follicular cell membrane
Correct conjugation in the follicular lumen of DIT + DIT will form?
The thyroid hormone macromolecule in circulatory majority
The most potent form of circulating thyroid hormone
Question 9 Explanation:
DIT + DIT conjugation forms T4. This is, whilst the least potent form of thyroid hormone, the form that is most prevalent in the serum. As such, T4 measurements are routinely preferred to T3 for thyroid function testing. At the target cell, eg the placenta, a deiodinase enzyme converts T4 to its more potent T3 variant, or RT3, for intracellular nuclear transcription regulation to occur.
Which of the following peptides lack a similar structure
TBG has a higher affinity for
Which of the following deiodinase classes are upregulated in the gravid uterus?
Where does triiodothyronine exert its effect on BMR?
At which stage in pregnancy is it possible for maternal follicular cells to assist in fetal neurogenesis?
Which physiological process best describes a patient with primary hyperthyroidism?
Increased NIS (sodium-iodide symporter) synthesis and expression
Increased follicular stimulating hormone (FSH)
Decrease in the activity of the paraventricular nucleus
Question 15 Explanation:
This is a relatively challenging question requiring several orders of thought and application of knowledge. If you felt confident with this answer, well done, if not that's fine. Revise the transport of substances into the follicular cells.
On examination of the patient’s neck, a bilateral bruit is auscultated lateral to the proximal trachea.Which of the following is the more appropriate diagnosis?
Question 16 Explanation:
The stem describes a thyroid bruit indicative of neovascularisation of a hypertrophic thyroid gland. As such, the most common form of hyperthyroidism - and an option here as it happens - is Graves’ disease.
Once you are finished, click the button below. Any items you have not completed will be marked incorrect.
There are 16 questions to complete.