Thyroid II Flashcards
(22 cards)
hyperthyroidism
thyrotoxicosis is the state produced by hyperthyroidism
two most common causes are Graves diseases and thyroid adenomas
Graves disease
autoimmune disorders associated with an antibody that stimulates TSH receptor
syndrome that
consists of hyperthyroidism, goiter, opthalmopathy, and occasionally a dermopathy referred to as pretibial or localized myxedema
Graves disease: autoantibodies to the thyrotropin (TSH) receptor
activate the receptor, thereby stimulating thyroid hormone secretion and thyroidgrowth
Graves disease: Graves opthalmopathy
volumes of both the extraocular muscles and retroortibal connective and adipose tissue are increased
possible paralysis of eye muscles, damage to optic nerve and corneal ulceration
Graves disease: Goiter
enlargement of the thyroid
hyperthyroidism
Goiter: nodular
thyroid nodules are very common (small nodules)
most thyroid nodules are benign (95%) overgrowths of normal thyroid tissue
Goiter: small and large goiters
small: sometimes can be detected more easily by having a person drink
large: diffuse enlargement coupled with symptoms of hypothyroidism. Goiter due to elevation in TSH secondary to insufficient iodide in the diet
Hyperthyroidism: eyes
hyperthyroidism causes some eyelid retraction (lid lag) and bright eyed stare
^^increased sympathetic activity. Unrelated to the ophthalmopathy that occurs in Graves disease
Hyperthyroidism: skin
warm, moist skin due to vasodilation
smooth skin due to decrease in the keratin layer
Hyperthyroidism: cardiovascular
rate and force of heart contraction increased
- pulse pressure widened and CO increased
- peripheral vascular resistance is decreased
- Afib in 10-20% of patients
- if severe, can have CHF
Hyperthyroidism: nervous system
behavioral and personai\lity changes
–psyhosis, agitation, and depression
–anxiety, restlessness, irritability, and emotional liability
–insominia also common
–hyperkinesia, tremor
–dementia and confusion
–seizures
Hyperthyroidism: respiratory system
respiratory distress
–resp muscle weakness and increased demand
–increased ventilatory drive
–goiter may depress trachea
–increase in breathing frequency
Hyperthyroidism: misc.
Increased GI motility and diarrhea
–increased appetite
–heat intolerance
–increased bone loss
Hyperthyroidism: treatment
beta blockers
thionamides: methimazole (preferred-1x daily) and propylthiouracil (better during pregnancy but bad for liver)
radioiodine ablation: widely used
surgery
Hypothyroidism: causes
postablative (thyroidectomy), iodine deficiency, tx with lithium, and thyroiditis
autoimmune throiditis includes Hashimoto’s disease
female:male ratio 5:1
TSH/goiter- hypothyroidism due to a thyroid defect results in elevated TSH and a goiter
Hypothyroidism: skin
myxedema, mucinous material is deposited in skin
skin is pale and cool
thickening of skin
slow would healing
heair may be coarse, loss is common
nails become brittle
Hypothyroidism: cardiovascular system
–decrease in CO
–possible hypertension secondary to increased peripheral vascular resistance
–peripheral effusion
–hypercholesterolemia
Hypothyroidism: nervous system
adult (myxedema)- slowed mentation, poor concentration and short term memory, social withdrawal, depressed mood, lethargy, fatigue, psychosis, confusion, and disorientation
congenital (cretinism)-permanent brain damage if not corrected shortly after birth. Cretins are permanently mentally retarded and are short if deficiency is not corrected. T4 and TSH tested at birth.
Hypothyroidism: respiratory system
fatigue, SOB on exertion
–decreased exercise capacity
–hypoventalation due to resp muscle weakness
Hypothyroidism: misc.
cold intolerance
dec appetite, only mildwt gain
husky voice
dec gastric emptying/intestinal motility (constipation)
Hypothyroidism: treatment
-thyroid hormone replacement (thyroxine T4 is tx of choice)
Thyroid function assays
TSH assays: normal range of serum TSH is about 0.5-5.0 mU/L
serum total T3 and T4: normal T4 is typically 4.6 to 11.2 ug/dL and serum T3 tpically range 75 to 195 ng/dL
