Which hormone is more potent and which is mostly made in thyroid gland?
T3 more potent. T3 made 20% in thyroid and rest is conversion in tissue. 1 day half life.
T4 thyroid gland only and 7D half life.
Three proteins that transport thyroid to tissue?
1. Serum thyroxine-binding globulin
2. Thyroxine binding prealbumin
Describe the regulation of thyroid release?
Hypothalmus will release thyrotropin releasing hormone (TRH)>>TRH stimulates release of thyroid stimulating hormone (TSH) from pituitary.>>TSH stimulates release of thyroid hormone>>>TSH release is regulated by the amount of circulating free hormone via negative feedback.
What are the etiologies of hyperthyroidism?
TSH secreting tumors
Toxic multinodular goiter
S/Sx of hyperthyroidism?
General-heat intolerance,increased sweating,weight gain
Head-thinning hair, fine texture
Eyes-prominence of eyes, lid lag or retraction
Neck-soft, diffusely enlarged goiter
Cardiac-palpitations, high output failure, edema, increased pulse and systolic pressure, tachyarrhythmias
Skin-hot flushed skin
Neuromuscular-fatigue, weakness, tremor
Emotional-insomnia or shorten sleep cycles
Tx for hyperthyroidism?
3. antithyroid medications
4. BB for all tachycardia
Causes of thyroid storm?
Radioactive Iodine treatment
Sudden WD from anti thyroid medications
Tx for thyroid storm?
PTU followed by a large dose of Iodine
Supportive: Beta blockade, Corticosteroid administration, APAP for antipyretic. NSAID and ASA displace thyroid.
What are the goals of radioactive iodine?
I is incorporated into the thyroid gland and destroys tissue. Goal is euthyroidism but most of the time hypothyroidism occurs.
CI in pregnancy.
MOA of Iodine treatment?
Inhibits thyroid hormone synthesis by feedback inhibition and decreases the vascularity of the gland
Primary disease state for hypothyroidism?
1. Hashimoto's disease
2. Iodine deficiency-Primary
3. Thyroid Hypoplasia
Medications that can cause hypothyroidism?
excessive iodine intake
excessive thioamide intake
S/Sx of hypothroidism?
General-cold intolerance, decreased sweating, easy fatigability
Head-dry brittle sparse hair, large tongue, puffy face
Eyes-edematous eyelids, drooping eyelids
Neck-goiter in primary hypothyroidism
Cardiac-enlargement, poor heart sounds, low outout failure, dyspnea
Extrem-broad hands and feet, cold dry skin
Muscle pain and weakness, emotional instability, depression and lethargy