Hypothyroidism Flashcards
What releases TRH?
Hypothalamus
What releases TSH?
Anterior Pituitary
What are the three substances the thyroid gland produces?
T3
T4
Calcitonin
Which of the following is the most active form of thyroid hormone? A) Bound T4 B) Bound T3 C) Free T4 D) Free T3
D
free forms are able to pass through cell membranes while the bound forms cannot do this, the active form of thyroid hormone= T3
List the components needed to make T4 aka thyroxine
Zinc, B1, B6, Tyrosine, Iodine, Vanadium, B2, Vitamin C
What are the two components needed to convert T4 to T3 (triiodothyronine)?
Progesterone and Se
80% of the circulating pool of thyroid hormone is composted of ____.
T4…so 20%= T3
Deiodination of T4 results in what?
Formation of reverse T3 which is inactive
Disease of the hypothalamus is said to be \_\_\_ hypothyroidism. A) Primary B) Secondary C) Tertiary D) Quaternary
C
\_\_\_\_ hypothyroidism accounts for 95% of cases. A) Primary B) Secondary C) Tertiary D) Quaternary
A
Most cases of primary hypothyroidism are due to? A) Idiopathic atrophy B) Lymphocytic thyroiditis C) Congenital D) None of the above
B
95%= lymphocytic or idiopathic
5%= secondary congenital/acquired or primary congenital
Which of the following treats hyperthyroidism in cats, with overuse causing hypothyroidism? A) Glucocorticoids B) Soloxine C) I131 D) Methimazole
C
Which of the following does not occur in euthyroid sick syndrome? A) Protein binding decreases B) Total T4 decreases C) Free T4 is converted to rT3 D) TSH is decreased
D
is normal to increased
List 5 drugs or drug classes that can cause low T4
Glucocorticoids
Carprofen
Furosemide
Phenobarb/Sulfas
Which of the following is not a CS of hypothyroidism? A) Hyperpigmentation B) Pruritic alopecia C) Weight gain D) Cretinism
B- not pruritic
other signs include failure to cycle in bitches, weak pups, decreased cardiac contracticility