Chapter 76 Flashcards
The thyroid is found below what?
The Larygneal prominence.
What 3 things will the thyroid gland control?
- How quickly the body burns energy. 2. How quickly the body makes proteins. 3. How sensitive the body should be to other hormones.
What is the major cell type in the thyroid gland?
Follicular.
What is the difference between T3 and T4?
T3 is 4 times as biologically active.
Thyroglobulin stores what?
Tyrosine
Where is thyroglobulin made and stored?
Made and stored in the thyroid gland.
What directly influences the trapping of iodine in the thyroid gland?
TSH
What happens to the thyroid gland in areas of the world with iodine lacking from diet?
They get enlarged and swollen, because there is a surge of TSH.
What is the Number 1 cause of thyroid problems worldwide?
Iodine deficiency
What is the Number 1 cause of thyroid problems in the U.S.?
Autoimmune disease.
93% of the hormone created in the thyroid gland is what (give both names)?
thyroxine aka T4
What is iodine recyling?
75% of tyrosine remains as mono- and diiodotyrosine which can be cleaved by deiodinase enzymes resulting in free iodine that can be used again.
An absence of deiodinase enzyme will result in what?
An iodine deficiency.
Only what form of T3 can be biologicaly active?
Only free thyroid hormones that don’t have a plasma protein bound to them.
T3 or T4 which hormone has a greater binding affinity for plasma proteins?
T4.
How long will it take for T3 and T4 hormones to be released to the tissues?
T3- 50% every day. T4- 50% every 6 days.
In general thyroid hormones do what?
Increase metabolic activity.
Hypothyroid equals what?
Retarded physical growth.
Hyperthyroid equals what?
Excessice growth.
What are the thyroid hormones effects of carbohydrates and fats?
They stiumulate almost all aspects of carbohydrate and fat metabolism.
Thyroid hormone is inversely proportional to what?
Total serum cholesterol levels.
Low levels of thyroid hormone leads to what?
Excessive deposition of fat in the liver and severe atherosclerosis.