Endocrine System Quiz Part I

Thyroid gland is not palpable.
Thyroid hormone is produced by the thyroid gland.
Two primary hormones: Triiodothyronine (T3) and Thyroxine (T4).
Main functions of thyroid hormone: regulates metabolism, heart rate, cardiac output, promotes growth and development, supports brain maturation in fetal and early postnatal life.
Signs and symptoms of thyroid disease primarily affect metabolism and cardiac function.
Iodine is a necessary compound for thyroid hormone synthesis.

Most common cause: Graves' disease, an autoimmune disorder.
Pathophysiology: Immunoglobulins stimulate thyroid-stimulating hormone receptors, leading to increased hormone synthesis.
Exophthalmos: Condition characterized by protruding eyeballs due to fluid accumulation and tissue buildup.
Common signs/symptoms: Weight loss, diarrhea, heat intolerance, nervousness, sweating, hyperexcitability, tachycardia, palpitations, and exophthalmos.
Treatment options: Thyroidectomy or radioactive iodine therapy.
Prototype medication: Methimazole (Tapazole), suffix -mazole.
Mechanism of action for Methimazole: Inhibits thyroid hormone synthesis.
Effectiveness of Methimazole is indicated by the reduction of hyperthyroid symptoms (e.g., bradycardia from tachycardia).
Risks of overtreatment: Extreme hypothyroidism signs, fever, rash, and leukopenia due to agranulocytosis.
Agranulocytosis is life-threatening with low granulocytes, increasing infection risk, and potentially low RBCs and platelets.
Regular checks while on Methimazole: CBC and hepatic function, as Methimazole can be hepatotoxic.

Jaundice is a sign of hepatic failure or injury associated with elevated bilirubin levels, leading to yellow discoloration of skin, mucous membranes, and sclera.
Assessing jaundice should always focus on the sclera.

Most common cause: Autoimmune condition known as Hashimoto’s thyroiditis.
Pathophysiology: Antibodies attack the thyroid gland, leading to fibrotic and non-functional tissue, resulting in decreased hormone production.
Treatment medication: Levothyroxine (Synthroid).
Mechanism of action: Synthetic T4 is converted to active T3 in peripheral tissues, correcting hypothyroidism.
Administration route: Oral (PO) or intravenous (IV).
Signs of effective treatment: Increased metabolic rate.
Possible side effects: Tachycardia, palpitations, dysrhythmias, severe angina, nervousness, tremors, anxiety, insomnia.
Important side effect to report: Any signs indicative of adverse reactions to levothyroxine.