Grave s disease (1 0 )

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Abigayle Walker
5 years ago
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1 THYROID DYSFUNCTION

hormones Weight loss, tachycardia, tiredness Diffuse

5 Grave s disease (1 0 ) Autoimmune - activating AB s to TSH receptor High concentrations of circulating thyroid hormones Weight loss, tachycardia, tiredness Diffuse goitre - TSH stimulating growth Opthalmopathy and dermopathy

6 Hyperthyroidism Level of the defect (1, 2, 3 ) Thyrotoxicosis Graves disease Toxic Adenoma Toxic Multinodular Goiter Chronic Thyroiditis

Exophthalmos bilateral exophthalmos (bulging eyes) is typical marker of autoimmune Graves' disease (hypethyreoidismus) Thyroid-stimulating autoantibodies mimic the action of TSH; they are directed

7 Exophthalmos bilateral exophthalmos (bulging eyes) is typical marker of autoimmune Graves' disease (hypethyreoidismus) Thyroid-stimulating autoantibodies mimic the action of TSH; they are directed against the thyrotropin receptor autoantigen (TSHR) on the thyroid follicular cell and similar receptors throughout the body and they may also react with these autoantibodies Subset of orbital fibroblasts is rich in this membrane receptor After stimulation the orbital fibroblasts are capable of differentiating into adipocytes and thus increase orbital adipose tissue

8 Symptoms and signs of hyperthyroidism

9 Hypothyroidism 1, 2, 3 Newborn Cretinism Lack of myelination Children Retarded Growth Disproportionate

11 Symptoms and signs of hypothyroidism

Myxedema (myxoedema) Hypothyroid myxedema is specific form of skin edema Increased activity of connective tissues leads to increased deposition of components of extracellular matrix (mainly

12 Myxedema (myxoedema) Hypothyroid myxedema is specific form of skin edema Increased activity of connective tissues leads to increased deposition of components of extracellular matrix (mainly glycosaminoglycans, proteoglycans) which retains large amounts of sodium ions and water Stimulation of fibroblasts is caused by increased amount of TSH which is able to bind to some membrane receptors and by this way it activates biosynthesis of extracellular matrix

14 Thyroid hormone resistance Mutation of the receptor. Characterized by high blood levels of both TSH and Thyroid hormones

15 Iodine deficiency Non-toxic goiter

16 Thyroiditis

17 Hashimoto s (1 o ) Autoimmune - AB s destruction of thyroid gland Low concentrations of thyroid hormones Lethargy, intolerance to cold Lack of growth and development Diffuse goitre - lymphocytic infiltration of gland + TSH stimulated growth

18 Euthyroid Syndrome Patient presents and complains of hypothyroid type symptoms Levels of Thyroid hormones (free & total), & TSH in low normal range. May be due to a 5 -deiodinase deficiency

19 Euthyroid Sick Syndrome Occurs in acute and chronic illness. Derangements of thyroid hormone levels are due to alterations in peripheral metabolism of T 4 and binding of T 4 to TBG. Fasting or illness also decrease the magnitude of TSH pulsations. Low T 4 belays poor prognosis.

20 Euthyroid Sick Syndrome Severity of Illness Free T4 Free T3 Reverse T3 TSH Mild Normal Reduced up to 50% Increased up to twofold Normal Moderate Increased Reduced up to 90% Increased up to several fold Normal Severe Reduced Almost undetectable Variable Reduced

22 Evaluating thyroid function The serum TSH is the best initial test of thyroid function. The latest generation of this assay has high sensitivity and is an excellent screening tool for those patients with a low pretest probability of thyroid disease.

23 TSH of mu/l is highly diagnostic for normal thyroid function. A high TSH (>5.0 mu/l is an indication for further testing,such as a free T4 (FT4) determination or a free thyroxine index (FTI) A patient who has a TSH in the gray zone ( mu/l) is very likely to develop hypothyroidism and should be screened regularly

40 Thyroid hormones in various disorders condition TSH Free T4 Free T3 Primary hyperthyroid Undetectable V.high High T3 thyrotoxicosis Undetectable Normal v.high Secondary hyperthyroidism Increased High High Subclinical hyperthyroidism Low N N

41 Thyroid hormones conc. In various Disorders Condition TSH Free T4 Free T3 Thyroid H Resistance or N Primary hypothyroidism or N Secondary hypothyroidism or N or N

B-Resistance to the action of hormones, Hormone resistance characterized by receptor mediated, postreceptor.

B-Resistance to the action of hormones, Hormone resistance characterized by receptor mediated, postreceptor. Disorders of the endocrine system 38 Disorders of endocrine system mainly are caused by: A-Deficiency or an excess of a single hormone or several hormones: - deficiency :can be congenital or acquired.