Exam II Flashcards
(20 cards)
What type of cells make up the Thyroid gland?
Follicle cells
What is the molecular structure of thyroid hormones?
Glycoprotein thyroglobulin
What cells line the thyroid gland?
Cuboidal epithelial cells
What fraction of iodides removed from the blood are used by the thyroid gland? What are they used for?
1/5th. Utilized for thyroid hormone synthesis
What is iodide trapping?
The process of concentrating iodide
What hormone influences the rate of iodide trapping?
TSH
What endocrine gland stores a large amount of hormones? How long wound the supply last?
Thyroid gland. 2 to 3 months
What is stored in follicles?
Thyroid hormone and a few triiodothyronine
What stimulates the cleavage of thyroglobulin?
TSH
What two hormones come from the cleavage of thyroglobulin?
Thyroxine (T4) and Triiodothyronine (T3)
93% of the released thyroid hormone is what? What is released 3% of time?
Thyroxine. Triiodothyronine.
What percentage of thyroxine is deiodinated to form more triiodothyronine?
50%
What is the speed of onset for Thyroid hormones?
Slow; they produce a long lasting action!
What is the latent period for thyroxine?
10-12 days
What is the latent period of Triiodothyronine?
6-12 hours
Thyroid hormones activate __________________________ of genes and _______ receptors.
Nuclear transcription, Nuclear
What is the primary function of the thyroid gland in children?
Increase linear height
How does the thyroid gland increase linear height in children?
Stimulate enzymes of protein anabolism **
Stimulate osteoblast cell activity **
Increase secretion of Somatomedin (Insulin-like Factor 1)
Increase secretion of Somatotropin Hormone ***
(promoter of bone growth)
What is the primary function of the thyroid gland in adults?
Increase metabolism
What is the secondary function of the thyroid gland in adults?
Stimulate the neuromuscular system
