thyroid disorders Flashcards
inadequate hormones, manifested as tired
Hypothyroidism
too much secretion of thyroid hormones → fast metabolism + uses energy → tiring
(pagod pa rin)
Hyperthyroidism
One of the largest endocrine glands
A small organ located in front of the neck, wrapped around the windpipe or trachea
Thyroid gland
Butterfly-shaped, smaller in the middle with two wings or lobes that extend around the side of the throat
Two cone-like lobes or wings
Thyroid gland
_____________ (right lobe) and _____________ (left lobe) connected via the ___________ (the bridge between the lobes of the thyroid)
lobus dexter; lobus sinister; isthmus
Hypothalamus releases ______________ which stimulates the anterior pituitary gland
thyrotropin releasing hormone (TRH)
Pituitary gland releases __________________ which stimulates the thyroid gland
In the presence of TRH
thyroid stimulating hormone (TSH)
Thyroid gland releases ___ and ___, which perform the thyroid functions
T3 and T4
Regulate the rate of metabolism and physiological functions (heart rate, sweating
and energy consumed)
Affect the growth and rate of function of many other systems in the body
T3 and T4
If thyroid hormone levels are adequate, T3 and T4 signals the hypothalamus and anterior pituitary gland to stop stimulating = no thyroid hormone production (t or f)
T
Thyroid hormones (T3 and T4) is regulated by
TSH
Low levels: Hypothalamus releases _________ that triggers TSH release from the pituitary gland
TRH
High levels: Hypothalamus _______ TRH release and anterior pituitary gland ________TSH release
stops
system that regulates the levels of TRH, TSH, T3 and T4
Negative feedback system
85% - 90% (majority)
T4
Majority is converted into T3 (removal of ___________)
1 iodine – deiodination
10% - 15% (more active)
T3
T3 bulk is derived by deiodination of T4 in ____________
peripheral tissues (liver, kidneys)
Deiodination of T4 yields __________ T3
■ a molecule with no known metabolic
activity
Reverse
Two principal thyroid hormones:
Thyroxine (T4)
Triiodothyronine (T3)
L-3,5,3’,5’-tetraiodothyronine
Thyroxine (T4)
T3 and T4 are derivatives of _________ bound covalently to iodine
Tyrosine
L-3,5,3’-triiodothyronine
Triiodothyronine (T3)
“pro-hormone of T3”
is better for transport through the body
T4