A patient is seen in a community clinic and is diagnosed with hyperthyroidism (G

Question

A patient is seen in a community clinic and is diagnosed with hyperthyroidism (Graves disease). The physician orders a thyroid panel and the following results are returned to the clinic. TSH low, T3 high, T4 high. The patient complains of heat intolerance, diarrhea, anxiety, and difficulty sleeping.

1. If you consider how the hypothalamic pituitary regulation of endocrine function, can you explain why in this patient although the thyroid gland is producing too much hormone the TSH level is low?

2. Is the above control an example of positive or negative feedback?

Explanation / Answer

1.There are two important thyroid hormones-T3 and T4.

TSH (Thyroid Stimulating Hormone) is released by the pituitary gland.

In Graves disease,the immune system creates the antibodies that results in more production of the thyroid hormone than the actual requirement of the body

These antibodies are called Thyroid Stimulating Immunoglobulin -(TSIs).Stimulation of the TSIresults in more production of the thyroid hormone leading to the condition - Hyperthyroidism.

Because of the increase production of T3 and T4 level,TSH level will remain low as a measure taken by the pituitary gland for the excess T3and T4hormones in the blood.

2.Graves disease is an autoimmune disorder.

Neative feedback occurs in Graves disease because of raised T3 and T4 levels,TSH levels remain very low and protein bound iodine remains elevated.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.