Thyroid

Question 1

TSH stimulates what?

Answer 1

thyroid gland to produce: Thyroxine (T4) and Triiodothyronine (T3) at a ratio of 4:1
T3 is the biologically active form and is metabolized from T4 in peripheral tissues

Question 2

Thyroid hormone receptor actions

Answer 2

Inhibition of gene expression when no thyroid hormone is present.
Corepressor dissociates from the complex and transcription occurs when thyroid hormone is present

Question 3

Graves disease

Answer 3

autoantibody activates the TSH receptor, inc T4, T3

Question 4

Hashimoto’s disease

Answer 4

Destructive antibody attacks the thyroid gland, inc TSH levels in plasma

Question 5

Hypothyroidism

Answer 5

Lethargy, Fatigue, loss of appetite, increase weight
Can lead to: hyperlipidemia, cardiac dysfunction, osteoporosis, exaggerated response to CNS depressants like narcotics and benzos.
Replacement therapy: Levothryoxine T4 (Synthroid), Liothyronine T3. Liotrix (mixutre in 4:1 ratio. No drug interactions or adverse effects

Question 6

Hyperthyroidism

Answer 6

Causes: thyroid hormone ingestion, Grave’s disease, hyperfunctioning adenoma, goiter
Signs: high metabolic rate, nervousness, weight loss, tachycardia, tremor, dry skin and hair
Treatment: Radioactive Iodine- drug concentrated in thyroid where the Beta particles destroy the gland
Propylthiouracil- inhibits thyroid peroxidase- enzyme responsible for synthesis of thyroid hormones
Surgery
Adverse effect: Hypothyroidism