Thyroid Flashcards
Where does parathyroid hormone work?
Bone and kidney
How is PTH stimulated?
Decreased of Calcium and increased of PO4
What does PTH do?
-Stimulates osteoclastic bone resorption
-Stimulates bone formation that is couple to bone resorption
-Increases renal tubular reabsorption of Calcium*
-Enhances renal elimination of phosphates*
What do thyroid C cells do?
The opposite of PTH
-inhibits osteoclast resorption
-delays Calcium absorption from intestine
-Increases calcium urinary excretion
How are c cells in the thyroid stimulated?
High blood calcium
Where does thyroid hormone synthesis occur?
Follicules
What hormone are follicular cells under control of?
TSH
Where are thyroid hormones stored in?
Gelatinous protein colloid
What organ uses iodine?
Thyroid
What portion of the iodine is absorbed?
1/3 of diet iodine goes to thyroid, the rest is excreted by kidney
Iodide binds to amino acid _ residues in the _ _.
tyrosine, thyroglobulin molecule
Where is the thyroglobulin molecule when its binding to iodide?
In the cell
Which thyroid hormone is produced more?
T4 = 97%
Which thyroid hormone is produced more?
T4 = 97%
T4 goes where after being synthesized?
Liver- turns into T3 and rT3 inactive form of T3
Which thyroid hormone is most biologically active?
T3
What transporter portion for thyroid hormones is created in liver?
TBH thyroid binding globulin- it can determine your levels of free T3 and T4
What is the function of thyroid hormones?
Biological catalyst- oxidative and metabolic reactions
T3 controls 50 of the metabolism and T4 the other half.
Growth & maturation of skeletal system
Decrease- short, delayed maturation
Increase- increased osteoclastic bone resorption and bone less
What is most common impairment of endocrine system?
Thyroid hormones
What is the first strategy of thyroid function tests in the US?
Pituitary TSH
