thyroid Flashcards
thyroid: anatomy
2” butterfly shaped gland
secretes T3 and T4, iodine is necessary component
T3 is active form and allows thyroid function to work
T4 is bound and unactivated
regulated body metabolism that influences almost every body system
thyroid: patho
hypothalamus senses body needs more metabolism -> releases THR which stimulates anterior pit -> releases TSH which stimulates the thyroid -> release T4 (thyroxine) which is converted to T3
thyroxine inhibits anterior pit and hypothal
measure TRH, TSH, T3 and T4 to know if the issue is thyroid or before
thyroid dysfunction
hypo or hyper
primary most common, at glandular level, F > M, can see enlargement of gland with both -> goiter
goiter can occur with or without (non toxic) S of thyroid dysF
causes: excess pit TSH, decrease Iodine (TSH accumulates), goitrogens - meds that cause enlargement (Li), monitor levels
hypothyroidism: types
insufficient T3 and T4
primary: thyroid doesnt secrete enough T3 +T4, high TSH
secondary: pit doesnt secrete enough TSH, low TSH + T3 + T4 -> brain dysF
hashimotos thyroiditis = autoimmune disorder, most common cause of primary -> thyroid receptor antibodies, antithyroglobulin antibody, antithyroperoxidase antibody: hallmark of disorder
antibodies attach thyroid
hypothyroidism: rf
F, >50, white, preg, hx of other autoimmune, fam hx, meds (Li, amniodium), treatments for hyperthyroidism
hypothyroidism: cm - early
decreased metabolism
non specific
cold intol, weight gain, lathargy, fatigue, memory deficits, poor attention span, increased chol, muscle cramps, raises carotene levels (yellow), c, decreased fertility, puffy face, hair loss, brittle nails
hypothyroidism: cm - late
below normal temp
brady
weight gain
decreased LOC
thick skin
cardiac complications (cardiomegaly
hypothyroidism: cm - affects all body S
raise chol - hld
raise carotene - yellow skin
cause anemia
decrease filtration by kidney (r/o med tox)
can cause hoarse voice
hypothyroidism: cm - myxedema
untreated
severe hypothyroidism (coma), derm change -> skin thick and hair loss, life threatening, loss of brain F
hypothyroidism: dx
high TSH, low T3 and T4, antithyroglobulin, antithyroperoxidase antibodies
hypothyroidism: tm
levothyroxine, sx if needed
hyperthyroidism
thyrotoxicosis
excessive T3 and T4, thyroid stimulating antibodies
primary: thyroid -> graves disease - most common, autoimmune stim of thyroid
secondary: pit, increased TSH
tertiary: hypothalamus, excess TRH
secondary and tertiary indicate a problem in the brain
other causes: thyroid adenoma, subacute thyroiditis, toxic multinodular goiter, excessive iodine ingestion (Jod-Basedow S), excessive thyroid hormone replacement
hyperthyroidism: rf
fam hx, >40, F, white, meds (amniodium), increase Iodine intake, preg (hormones similar to TSH)
hyperthyroidism: cm
autoimmune, excess T3 and T4, thyroid stimulating antibodies
nervousness, insomnia, sensitivity to heat, weight loss, gland usually enlarged and palpable, audible bruit may be heard because of high glandular blood flow, afib, myxedema
exopthalamus: periorbital edema and eye buldge (graves ophthalmopathy), F > M, inflam disorder, vision impairment
afib bc increased sensitivity to catecholamines
hyperthyroidism: dx
low TSH, high T3 and T4, antithyroglobulin, antithyrotropin receptor antibody, US with color doppler eval - excessive BF in thyroid - bruit, radiocative Iodine scanning and measurements of I uptake -> diffusely distributed over entire gland (cancer if not - [])
