Endocrine 2 Flashcards
Where are thyroid hormones stored?
Extracellularly for 2-3 months
Hypothalamus secretes ___ which stimulates pituitary gland to secrete ___ which stimulates thyroid to secrete ___ and ____
TRH
TSH
T3/T4 can now turn off hypothalamus and pituitary
percentages in pop with hypo or hyper thyroidism
80% have hypo. T3 and T4 are low. TSH is high.
20% have hyper T3 and T4 are high. TSH is low.
1 cause of hypothyroidism in US and world.
US: Hashimotos 90-97%
World: Insufficient iodine intake
Hypothyroidism ocular symptoms
1/3 of eyebrows missing (queen Ann’s sign)
Superior limbit keratoconj
Exophthalmos
Symptoms of hashimotos
Myxedema- deposition of mucopolysaccharides. Causes edema.
Lethargy, cold intolerance, decrease ap, weight gain.
Tx hashimotos with
levothyroxine / synthroid
Main cause of hyperthryoidism
Graves autoimmune disease. 60-80%
Others: Goiter, excess iodine.
What autoimmune disease is most commonly associated with TED
Graves
50% of graves pt’s develop TED
Thyroid eye disease
Lymphocytic infiltration of orbital soft tissue.
Fibroblasts deposit mucopolysacharids and cause edema (myxedema) = enlarged EOMs.
Most common cause of proptosis/diplopia in adults
TED.
Myxedema causing swelling/enlarged EOMs.
Could be unilateral or bilateral
___% of graves pt’s develop TED
__% of TED patients have graves
50
85
Is TED severity related to severity of systemic disease?
No
Contraindications if pt has TED
smoking!
4x increased risk of TED
Early and late signs of TED
Early- eyelid retraction (90%)
Late- exophthalmos (60%) and EOM restriction/diplopa (40%)
TPO/thyroperioxidase
Enzyme that synthesizes T3/T4. May see TPO antibodies in both hashimotos and graves, although more common in hashimotos. (95%)
Which thyroid disease would you see a TSH receptor antibody?
Graves (90%)
Response to low serum calcium levels
Parathyroid secretes PTH to raise Calcium levels in the blood by increasing osteoclast activity and increasing calcium reabsorption
Response to high serum calcium levels
Parafollicular cells in thyroid secrete calcitonin to lower serum calcium levels.
Calcitonin tones ur bones!
75% of hypoparathyroidism is due to
Neck surgery
Result of hypoparathyroidism
Hypocalcemia, increased phosphorus levels.
(PTH usually increases serum calcium levels. Without, will result in low calcium)
Causes muscle cramps and paresthesia.
Ocular: Cataracts
Decreased PTH, decreased calcium, increased phos
85% of hyperparathyroidism is due to
Parathyroid adenoma.
Result of hyperparathyroidism
Excess PTH secreted, resulting in an increased level of calcium in the blood. 95% only involve 1 of 4 glands Symptoms- 50-80% are asymptomatic Osteoporosis Kidney stones
Will see increase in PTH, increase in calcium and decrease in phos
Ocular: Band keratopathy due to calcium build up
Conj concretions in palpebral conj
Ocular results of hypo and hyperparathyroidism
Hypoparathyroidism- Decrease PTH = decrease calcium levels. Cataracts.
Hyperparathyroidism- Increase PTH= increase calcium levels. Band keratopathy and palpebral conj concretions.
*Most people are asymptomatic tho
Vitamin D deficiency can result in what based off age
Rickets in children
Osteomalacia in adults
(Softening and weakening of bones)
Pineal gland location
Posterior midbrain in the brainstem
produces melatonin
Parinaud syndrome
Pineal gland tumor.
Upward gaze deficit - sunset
Dx with MRI
Due to pinealoma or hydrocephalus
Signs: Lid retraction, papilledema, nystagmus.
Causes of parinaud syndrome/Dorsal midbrain syndrome.
Due to pinealoma or hydrocephalus (accumulation of CSF in the brain)
Thyroid gland targets which cells in the body
All
Thyroid gland regulates
The basal metabolic rate.
O2, body temp, gastric motility, HR
Why do you get a goiter with hypo and hyperthyroidism?
Hypo- body trying to stimulate it
Hyper- due to overaction
How to treat hyperthyroidism
Radioactive iodine= TOC
Most common cause and symptoms of hypoparathyroidism and hyper
Hypo- neck surgery (80%), muscle cramps, numb limbs, brittle nails/hair.
Hyper-Parathyroid adenoma, asymptomatic
