What are the two hormones that the thyroid release?
What cells release T4/T3?
What cells release calcitonin?
What is the process by which T4/T3 get into the blood stream?
Iodine comes from blood via Na+ channel then pendrin
Thyroid peroxidase puts I- onto thyroglobulin
Carries T3/T4 into cytoplasm
Broken down by lysosome
What are the neuroendocrine effects of TH?
Increased sensitivity of SNS stimulation
Increased stimulation of all other endocrine organs
What are the cardiac effects of TH?
via HR + contractility + BP
What are the respiratory/metabolic effects of TH?
Increased O2 + energy consumption
Increased erythropoiesis leading to O2 delivery
What are the regulatory hormones of the thryoid?
-- and --
What are the four effects of TSH?
Stimulate Iodine symport (NIS)
Activates thyroglobulin synthesis
Activates throid peroxidase
Stimulates lysosomal breakdown of Thyroglobulin
What are the signs a dog is hypothyroid?
Overall sad appearance
What are the four major reasons for hypothryoidism?
Nutritional status/Underlying disease
What drugs can induce hypothyroidism?
Which of the drugs that cause hypothyroidism cause there to actually be clinical symptoms?
What is the drug for hypothyroid?
How is levo absorped/given?
Bioavaliblity decreased with food
How is levo handled in the body?
Most bound to plasma protein
How is levo metabolized?
What are the contrindications for levo?
Acute myocardial infarction
Untreated adrenal insufficency
What are the adverse side effects of levo?
What are the signs of hyperthryoid in a cat?
Weight loss with atrophy
Can feel thyroid lobes
What can cause adenomatous hyperplasia of the thyroid?
Associated with altered signaling sensivity to TSH
High levels of dietary Iodine/soy may be the cause
When starting to treat a cat with hyperthyroid what is important to remember?
Unmasking CKD in older cats
Increased CO leads to better perfusion of the kidneys, therefor increased GFR
What are the signs of renal failure?
What is the drug of choice for hyperthyroid? Where does it work?
Inhibits production of Thyroid peroxidase
Inhibits binding of T4/T3 to Thyroglobulin
How is methimazole given?
What are the adverse effects of methimazole?
Forming anti-nuclear bodies
What should be done if you are seeing GI effects of methimazole?
What is the rate at which methimazole works?
takes 3 to 4 weeks to normalize T4 levels
How is I131 used?
Irreversible treatment of hyperthryoid
Destroys the cells but aren't powerful enough to destroy C cells