Endo - Thyroid Flashcards
What are the TSH levels in hyper and hypothyroidism?
Hyper - TSH is SUPPRESSED, by the high thyroid hormones, so low TSH level
Hypo - TSH is HIGH, as trying to stimulate more thyroid hormone release
What is the exception to TSH being low in hyperthyroidism?
Pituitary adenoma - secretes TSH, so levels will be high instead of low
What is the exception to TSH being high in hypothyroidism?
Pituitary or hypothalamic cause of the hypothyroid (secondary hypothyroidism), in which TSH level will be low
What are the T3 and T4 levels in hyper and hypothyroidism?
Hyper - Raised T3 and T4
Primary Hypo - Low T3 and T4
Secondary Hypo - Low T3 and T4
What are the antibodies that are against the thyroid gland itself, and what are they present in?
Antithyroid Perioxidase (anti-TPO) antibodies
Present in Grave’s Disease and Hashimoto’s Thyroiditis
What are the antibodies called that are against Thyroglobulin, and what is Thyroglobulin?
Antithyroglobulin antibodies
It is a protein produced and extensively present in thyroid gland
Present in Grave’s, Hashimoto’s, and thyroid cancer
What are TSH Receptor Antibodies, and what do they classically cause?
Autoantibodies that mimic TSH, bind to TSH receptor, and stimulate thyroid hormone release
Cause of Grave’s Disease
What are radioisotope scans?
Used to investigate Hyperthyroidism and thyroid cancers
What does radioisotope scans entail?
- Radioactive iodine given orally or IV
- Travels to thyroid where it is taken up by cells
- Iodine normally used by thyroid cells to PRODUCE THYROID HORMONES
- More active the thyroid cells, faster radioactive iodine is taken up
- Gamma camera used to detect gamma rays emitted from radioactive iodine
- More gamma rays emitted, more radioactive iodine taken up
What pattern of radioactive iodine uptake would you see in which thyroid disease?
- Diffuse high uptake - Graves Disease
- Focal high uptake - Toxic multinodular goitre and adenomas
- ‘Cold’ areas (abnormally low uptake) - can indicate thyroid cancer