360 - Hormones Flashcards
most common hormone tests performed in core
hCG and thyroid
how can hormones be measured?
several techniques, including immunoassay and instrumental techniques such as GC-MS
how can hormones be measured?
several techniques, including immunoassay and instrumental techniques such as GC-MS
sample collection or hormone assay considerations
- nutrition
- diurnal variation
serum iodide is trapped in the ________, and iodine is incorporated into ___________.
thyroid; tyrosine
this is key to the synthesis of the thyroid hormones
iodine
- rate-limiting step is the iodine transport to the follicles
the process of thyroid hormones being released
- TRH from hypothalamus secreted due to low thyroid hormone concentrations
- TRH interacts w anterior pit gland = TSH
- TSH binds to thyroid follicular cells = T3 and T4, and reverse T3
the major secretory product of the thyroid
T4
30X higher in plasma than T3
Both free and bound hormones are found in circulation
T3 and T4 transported in blood by this
TBG; thyroid binding globulin
transthyretin
albumin
This binding protein has the greatest affinity for T4
TBG
also the most important in regulating free T4 concentration
In the ________, free T4 is deiodinated to create biologically active ___.
liver; T3
what does T3 do?
regulates the rate of cellular oxidation and metabolism
T3 helps regulate cellular uptake of glucose and influences protein metabolism
T or F. Increased thyroid hormone concentrations inhibit the pituitary response to TRH
T!
T or F. An increase in thyroid hormone concentrations will cause an increase in TRH and TSH secretion
F! Decrease in thyroid hormone…
Graves’ disease
characterized by the formation of autoantibodies specific to the TSH receptor
The autoantibodies stimulate the receptor leading to hyperthyroidism
Hashimoto thyroiditis
characterized by cell-mediated autoimmunity, causing thyroid dysfunction
clinical presentation includes goitre, thyroiditis, and frequently hypothyroidism