Thyroid Flashcards
what is the thyroid
2 in butterfly shaped gland that release T3 and T4
what is T3
triiodothyronine
- active form
what is T4
thyroxine
- free and bound
- gets converted to T3 at the tissue when it loses an I atom
what does T4 do
regulates the body’s metabolism
what is the necessary component in the synthesis of thyroid hormone
iodine
review of the thyroid feedback system
- hypothalamus releases thyroid releasing hormone (TRH)
- TRH stimulates anterior pituitary to release thyroid stimulating hormone (TSH)
- TSH stimulates the thyroid gland to produce T4
- T4 levels will dictate TRH and TSH release
what are the thyroid dysfunctions
- either hypo or hyper
- primary disorders are most common (thyroid gland itself)
- more women
- enlargement of thyroid w disorders
what is a goiter
enlargement of thyroid caused by low I levels that prevents release of T4 or build up of TSH
- no sx = non toxic
what is a goitrogen
foods and other substances that cause an enlargement of thyroid
- ex lithium
what is hypothyroidism
T3 and T4 levels are low
primary disorder hypothyroidism
inc release of TSH from pituitary and dec in T3 and T4
secondary disorder hypothyroidism
hashimoto’s
- autoimmune disorder, most common cause, abx attack thyroid, low T3/4 inc TSH
what to look for with hashimoto’s
- thyroid receptor antibodies
- antithyroglobulin antibody
- antipyrotheroxidase antibody –> hallmark
risk factors for hypothyroidism
female
over 50
white
pregnant
hx of autoimmune disorders
fam hx
medications
treatments for hyperthyroidism
early manifestations of hypothyroidism
cold intolerance
wt gain
lethargy
fatigue
poor attention span
inc cholesterol
muscle cramps
raise in carotene levels –> cause yellow skin
C
dec fertility
puffy face (facial and eyebrow edema)
brittle nails
later hypothyroid manifestations
below normal temp
bradycardia
wt gain
dec LOC
thickening skin
cardio complications –> cardiomegaly
hypothyroidism affects all organs
raises cholesterol
raises carotene
causes anemia
dec filtration of kidneys
cause hoarse voice
what is myxedema
a coma that results from untreated hypothyroidism
- lose of brain function
- dermatological changes
diagnosis of hypothyroidism
high TSH level
low T3 and T4
antithyroglobulin
antithyroperoxidase
what happens with primary and secondary hypothyroidism
primary: high TSH and low T3 and T4
secondary: TSH and T4 are low
what is the treatment of hypothyroidism
replacement hormone therapy –> levothyroxine
levothyroxine moa
converted to T3 in body
levothyroxine nursing considerations
half life 7 days
takes about a month to work
se: too high then can cause hyperthyroidism –> need to get correct dose
food and other drugs and affect absorption so take on empty stomach (30 mins before eating)
for warfarin: inc risk for bleeding
drugs taken for life
hyperthyroidism
excessive secretion of T3 and T4
- primary cause: thyroid producing too much T3 and T4
- secondary: pituitary over releasing TSH, rare
- tertiary: excess secretion TRH
