Endocrine Physiology ML:4 Flashcards
What is the functional unit of the thyroid gland?
follicles
How are thyroid hormones stored?
They are really hydrophobic so they can be bound to thyroglobulin which is a protein that is stored in the colloid
True or False: The thyriod hormone is stored in the colloid fluid until it is stimulated to be secreted
true
How are thyroid hormones transferred to the blood?
by protein carriers
TBG protein carrier
70%
TTR protein carrier
10-15%
Albumin protein carrier
15-20%
What kind of hormone is a thyroid hormone
hydrophobic amine hormone
-binds to receptors inside the target cell
Characteristics of T4
90% of secretion
“storage pool” in blood
converted to T3 inside target cells
Characteristics of T3
most active form (bound to receptors in target cells)
Three gland cascade: thyroid gland
-hypothalamus secretes TRH
-anterior pituitary secretes TSH
Thyroid gland secretes T3 and T4
What are the three actions of the thyroid hormone?
metabolic
permissive
growth and development
Metabolic actions
controls BMR and body temp mainly by increasing sodium and potassium
Permissive actions
increases catecholamine expression
Growth and development
TH is needed for normal production of growth hormone (GH) and essential for fetal CNS development and function and adult nervous system function