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56 Cards in this Set
- Front
- Back
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thyroid follicular cells secrete
thyroid hormones promote thyroid parafollicluar secrete? |
-T4, 20% T3, rest is converted in peripheral tissue T4-T3
-growth, energy, hear tproduction -calcitonin-tone down calcium blood levels |
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thyroid hormone syntehsis
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1. Iodine transport across epithelial cell BM
2. Thyroglobulin gene transcription 3. iodine + tyrosin + thyroglobulin 4. I- coupling to from T3-T4 catalyzed by thyroid peroxidase 5. thyroid hormone bound to Tg stores in follicular lumen 6. transported back and released |
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thyroid Hormone Transport
TBG increase/decrease |
-bound to plasma proteins(TBG)
-Asses fxn consider T3/T4 free plasma not just overal hormone lvels -TBG increase w/ prgenancy, birth control, tamoxifen- raising total plasma T4 but euthyroid -TBG decrease w/ glucosteroids, protein loss, and heparin, reducing total plasta T4 but euthyroid |
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Graves disease
caused by? Additional to usual hyperthyorid sx? |
-TSH AB stim-->excessive hormone production
-exophthalmos(occular proptosis): bilateral/unilateral, independent of thyroid levels -spasm of upper lid due to inflammation into orbital tissues and muscles which leads to eye being pushed outwards and compression of optic nerve -Pretibial myxedema: thickening of skin-->orange peal |
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Rgulation of thyroid
Hypothalamus Pituitary -feedback mechansim? what do hyp/hyper have? thyroid |
1. Hypothalamus-TSH acts on pituitary
2. Pituitary: takes fdbk from TSH and acts releases TSH(AP)-->growth of thyroid, idodide uptake, release of T3/T4 -TSH regulated by T3 cells, negative feedback - hypothyroidisim: low T3/T4, high TSH -Hyper: high free T3/T4, low TSH 3. thyroid: regulated by infrathyroid iodide levels, TSH. -excess levels inhbiti resposne to TSH, depletion enhances response |
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thyroid Strom
what is it? sx? follows? |
accelearted hyperthyroidism
-fever, prostration, severe tachycardia(A-fib), extreme sweating, restlessness, dehydration, shock -follows prolonged hyperthyorid state, related to increased binding sites for catecholamines |
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Role of TSH receptor
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-binds TSH--> T4/T3
-also binds TSH-Receptor stimulating Abs, TSH-receptor blocking Abs |
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Toxic Adenoma
caused by? diagnosed? |
-overproduction of hormone by single autonomous adenoma, rest of gland supressed
-hot spot on thyroid scan |
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Hyperthyroidism
also called? represents? sx? signs? |
-increase lvels of thyroid hormone(any cause)
Sx: overheating(heat intolerance) palpitations, dypnea, polyphagia(hungry panda), anxiety, nervousness, insomnia, increased stool freuency/diarrhea, weight loss, fatigue Signs: -rapid heart rate, tremors, WARM/MOIST, palmar erythema, nervous -eyes pop out -thyroid gland may or may not be nenlarged |
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toxic nodular goiter
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-autonomous sites of overproduction of hormones, multiple hot spots
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Subacut thyroiditis
caused by? limited? |
-post viral condition, dammage/inflammation causes leakage of performed hormones in follicular space so circulating levels are lower than other types of hyperthyroidisim
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Factitious hyperthyroidism
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-ingestion of thyroid hormones by medical personnel
-hamburger toxicosis- thyroid ground in beef neck muscles |
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Hyperthyroidism Treatment
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-decrease hormone production by inhibiting thyroid peroxidase enzyme
-counteract peripheral effect: drugs like beta-blockers -Radioactive iodine- shrink gland, knocks out entire gland -Surgery-partila or totla thyroidectomy |
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Hypothyroidism
also known as? Sx? |
-decrease in thyroid hormone levels
-cold intolerance, lethargy, myalgias, athralgia, depression, parasthesia, distortion of taste, smell, bizarre sense of humor, psychosis |
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Signs of hypothyroidism
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-cool coarse, dry yellow skin
-puffiness(periorbital edema) -brittle hiar -weight gain, deep harsh voice, slow reflexes -constipation -hyptoension, pericardial and pleural effusions, bradycardia, anemia -myxedeme coma(end stage) -weakness, hypothermia, stupor, hypoventiliation, hypoglycemia, coma, death |
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Causes of Hypothyrodisim
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-autoimmune
-hashimotos -raised TSH receptor blocking ABs -Iatrogenic -Iodine deficiency |
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Hashimotos thyroiditis(chronic lymphocytic thyroiditis)
caused by? also assoicated with? |
-raised levels of thyroid peroxidase antibody
-mitral valve prolapse |
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Hypothyroidism Treatments
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1. Replacement of T4 hormone
2. Combination therapy with T4, T3 is promoted but provides little benefit |
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thyroid Disease Diagnosis
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Serology Test
Iodine metabolism Imaging(ultrasound) |
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Serology Tests for thyroid disease
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TSH:
low = hyper high = hypo Free T4-change Autoimmune hypothyroidism: antithyroid antibodies |
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Iodine Metabolism Test
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-Radioactive iodine uptake: measures amount of radioactive iodine taken up by thyorid gland overtime
-good for subacute thyroiditis |
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dental implications
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Hyperthyroidism:
-thyroid storm, epinephrine sensitivity Hypothyroidism: -myxedeme coma, sensitivty to depressents(lose ability to cope with hypoxia or hypercapnia-->can stop breathing) |
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Calcium homeostasis:
-in plasma? -healthy? |
-55% bound to albumin or citrate/po4
-can be changed by certain meds -unbound-Ca2+ = active form -maintain constant level of Ca@+ in ECF, amount you lose = amount eat |
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Calcium Regulation:
controlled by: |
Parathyroid hormone
vitamin D Ca levels: can inhibit release of PTH, decrease levels sitmulate PTH |
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fxn of PTH
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-increase outflow of Ca into ECF via:
Kindey: 1,25 OH2 vitamin D production-->retention of Ca, excrete PO4 -Bone: resorption/release of Ca and PO4 -GI tract: increases intestinal Ca absorption |
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vitamin d 12OH2 D3 fxn
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-mediates Ca absoprtion in intestine and promotes bone formation
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Hashimotos thyroiditis(chronic lymphocytic thyroiditis)
caused by? also assoicated with? |
-raised levels of thyroid peroxidase antibody
-mitral valve prolapse |
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Hypothyroidism Treatments
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1. Replacement of T4 hormone
2. Combination therapy with T4, T3 is promoted but provides little benefit |
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thyroid Disease Diagnosis
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Serology Test
Iodine metabolism Imaging(ultrasound) |
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Serology Tests for thyroid disease
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TSH:
low = hyper high = hypo Free T4-change Autoimmune hypothyroidism: antithyroid antibodies |
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Iodine Metabolism Test
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-Radioactive iodine uptake: measures amount of radioactive iodine taken up by thyorid gland overtime
-good for subacute thyroiditis |
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dental implications
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Hyperthyroidism:
-thyroid storm, epinephrine sensitivity Hypothyroidism: -myxedeme coma, sensitivty to depressents(lose ability to cope with hypoxia or hypercapnia-->can stop breathing) |
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Calcium homeostasis:
-in plasma? -healthy? |
-55% bound to albumin or citrate/po4
-can be changed by certain meds -unbound-Ca2+ = active form -maintain constant level of Ca@+ in ECF, amount you lose = amount eat |
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Calcium Regulation:
controlled by: |
Parathyroid hormone
vitamin D Ca levels: can inhibit release of PTH, decrease levels sitmulate PTH |
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fxn of PTH
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-increase outflow of Ca into ECF via:
Kindey: 1,25 OH2 vitamin D production-->retention of Ca, excrete PO4 -Bone: resorption/release of Ca and PO4 -GI tract: increases intestinal Ca absorption |
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vitamin d 12OH2 D3 fxn
disfxn causes? |
-mediates Ca absoprtion in intestine and promotes bone formation
-rickets in children, osteomalacia in adults |
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Calcitonin fxn
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-opposite of vitamin D
-reduces circulating Ca/PO4 levels by inhibting osteolcast bone resoprtion -increase Ca-->stims calcitonin -naturually has no effect on calcium blaance but synthetic versions can used for therapy |
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other hormones involved in calcium homeostasis
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-Sex Steroids: etrogens-->anabolic/protective effects, lack of -->resorption
-Glucocorticoids: bone thinning/reduction of bone density by inhibiting ostelbasts -thyroid hormone: increase Ca realease from bone. Deficiency can lead to reduced skeletal growth(cretinisim) -growth hormone: promotes growth of bone and cartilage, excessive can cause abnormal growth(gigantism, acromegaly) |
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Hypercalcemia Sx
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-non-specific: malaise, fatigue, headaches, diffuse pains(calcium deposition in soft tissues)
-renal: plyuria, nephrolithiasis, urnary obstruction -gastrointestinal: nausea, vomiting, anoreixa, constipation -musculoskeletal: weak, myopathy, bone cysts, osteoporosis -neuropsychiatric: lethargic, ataxia, psychosis, stupor, coma -mestatis calcificaiton- in eyes, skin kidney stones bone and abdominal groans and psychic moans |
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Primary Hyperparathyroidism:
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-high PTH, serum Ca, low PO4
-Sx releated to elevated Ca -Osteitis Fibrosa Cystica(von Recklinghausens bone disease) -High PTH-->subperiosteal bone resorption-->marrow fibrosis, cystic reparative lesions(brown tumors) -causes bone pains/vetebral fractures -metastatic calcification(renal stones) |
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Hypercalcemia Malignancies
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-local osteolytic process in bone from invading cancer
-can rasie calcium through PTHrP |
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Hypercalcemia other causes:
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-Sarcoidosis and other granulomatous diseases-->increase Ca absorption
-granuloma cells convert Vit D to inactive-->lower bone deposition(vit D) and drive up PTH production(less Ca absorbed) -too much milk |
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hypercalcemia treatments
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-treat underlying cause
-drugs(bisphosphonates to inhibit bone resorption) |
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Hypocalcemia:
Sx |
-realted to neuromuscular excitability OR deposition of calcium in soft tissues(not cause and effect)
-parethesias of lips, fingers, muscle cramps, spasms, tetany, restlessness, depression, seizures -chovstek: tapping of facil nerve -trousseaus-carpal spasm -EKG changes: delayed repolarization |
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Hypocalcemia
causes? treatment? |
-hypoparathyroidism:
-idiopathic or post surgical thyroidectomy -glandular damage from iron overload(thalassemia), copper overload(wilsons), autoimmune destruction -renal failure-reduced vit D level, resistance to PTH action -decrease vit. D intake/metabolism -pancreatitis, crush injuries, citrated blood transfusion -treatment: Ca IV or Vitamin D |
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Bone mass trends?
Osteoporosis: characterized by? |
-Gain most bone during adolescence, after 35 start losing
-bone health dependent on levels of exposure to nutrients, hormones, physical activities, genetics -decrease in denisty and microarchitecture of bone |
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Classification of Osteoporosis:
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Type 1: bone loss acceleartion following menopause
-loss of estrogen which promoted bone deposition, also has protective effect against cytokine mediated osteoclast activation Type 2: constant bone loss related to other conditions -drugs, endocrine disease, malabsorption, immobilization |
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Clinical Presentation of Osteoporosis:
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-asymptomatic unless fracture
-vertebral fracture via minimal stress from recurrent small fractures over time(loss of height and classic hump) -fracture of wrist, hip, ribs, pelvis, humerus -hip fracture via minimal traumua-->pulmonary embolism, infection |
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Effects of aging
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Deficient:
-Vit D production in skin -12OHD3 production in kidneys-->decrease intestinal absoprtion-->decrease plasma calcium -->increase PTH-->increase bone resoprtion |
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Osteoporosis Diagnosis
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-Dual Energy Xray Absorptiomtry for bone desnity
-osteopenia: 1-2.5 SD below peak bone mass -osteoporsis: 2.5 SD below peak bone mass -Quantitative computed tomography |
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Osteoporosis Treatment/Prvention
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-Calcium and Vitamin D
-Estrogen repalcement(progestin) -Bisphosphonates: prevent bone resporption but may increase jaw bone necrosis -selective estrogen receptor modulators-effective but have sig. side effects -intranasal calcitonin -excercise |
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Pituitary Gland:
hormones? |
AP:
Growth Horme(GH): on organs Prolactin(PRL) : breasts ACTH: adrenal glands TSH:thyroid gland LH/FSH Posteiror: ADH vsopressin |
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Anterior Pituitary general problems
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-hypersecretion of hormones secondary to an adenoma
-hyposecretion of hormones-via compression, damage or infarct -local damage of expanding tumor: visual problems |
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AP Hypersecretion SX
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Hyperprolactinemia :
females: galactorrhea, irreuglar mesnes, amenorrhea Males: loss of Growth Hormone: acronmegaly in adults, gigantism in kids ACTH: cushings TSH: hyperparathyroidism |
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AP hyposecretion
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Prolactin: no breast feed
LH/FSH: kids: delay puberty Men: decrease libido, impotence, infertility Women: menstrual irregularity, amenorrhea, hot flushes, dypareunia TSH: hypoparathyroidism ACTH: adrenal insufficiency, Addisons |
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Posterior Pituitary
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-ADH deficient: Diabetes insipidus
-excessive dilute urine-->polydipsia -Syndrome of inappropriate ADH Secretion(SIADH) -excessive water retention, hyponatermia |
