VI-Thyroid Flashcards
functions of thyroid follicle
- collect and transport iodine/iodide
- syn thyroglobulin
- syn and release thyroid hormone into blood
iodide trapping
trapped/transported into follicle thru NIS (Na/I symporter) powered by ATPase bc going against gradient
PDS transporter
transports iodide and thyroglobulin into colloid
-for oxidation to iodine
TPO function
iodination of iodine to tyrosine residues
-form MIT and DIT
-requires hydrogen peroxide from dual oxidases
thyroid hormone effects
- growth, development, body temp, energy metabolism
- chronotropic, inotropic on heart, enhance resp to catecholamines
- stim lipolysis
- inc protein breakdown
- inc rate of carb absorption
- stim oxygen consumption by metabolically active tissues
presentation types of thyroid disorders
- hypothyroidism/myxedema- def of thyroid hormone
- hyperthyroidism/thyrotoxicosis - xs thyroid hormone
- goiter- enlarge thyroid gland
- thyroid nodule - focal/asym enlargement of gland from benign or malignant neoplasm, hyperthyroidism
- abnormal function test- clinically asymp aka euthyroid sick syndome
primary hypothyroidism
low T3/4 so no neg feedback
inc TRH and TSH
secondary hypothyroid
from impaired pituitary so low TSH -low T3/4
-no reg of TRH so high
tertiary hypothyroid
impaired hypothalamic function
all three TRH, TSH, T3/4 low
primary hyperthyroid
high T3/4 so low TRH and TSH from feedback
secondary hyperthyroid
dysfunction of pituitary
high TSH so high T3/4
-low TRH from feedback
tertiary hyperthyroid
hypothalamus disfunction
all three high TRH > TSH > T3/4
hypothryoid presentation
- bradycardia
- cold intolerance
- hypoventilation
- depression
- fatigue
- constipation
- puffy baggy eyes
- dry scaly skin
- dec CO
- inc body weight
- atherosclerosis
hyperthyroid presentation
- tachycardia
- sweating
- tremors
- rapid growth early
- heat intolerance
- high RR
- diff sleeping
- diarrhea
- dec body weight
- inc appetite
- upper eyelid retraction, lid lag downward gaze, staring appearance
