MEDICINE MCQ
ENDOCRINOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Iodide trapping
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Iodine trapping
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Iodinization
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Deiodinization
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Detailed explanation-1: -Iodine trapping and thyroid function The active uptake of iodide (I-) by the follicular cells involves an energy-requiring (ATPase-dependent) transport mechanism which allows I-to be taken up from capillary blood against both a concentration and an electrical gradient in exchange for Na+ (Box 3.5).
Detailed explanation-2: -Iodide is “trapped” in the thyroid gland by an active transport mechanism that is mediated by NIS. Once in the gland, iodine is rapidly bound to thyroglobulin (TG), and retention no longer requires active transport.
Detailed explanation-3: -NIS is an integral plasma membrane glycoprotein localized at the basolateral plasma membrane of thyrocytes (6). This protein plays an essential role in thyroid physiology by mediating uptake of iodide into the thyrocytes, a key step in thyroid hormone synthesis.