Metabolism of thyroid hormones 1. Uptake of iodide 2. Activation ofiodide(peroxidase) and iodination and coupling of tyrosine 3. Formation of thyroxine(t4)and triiodothyronine (l3) from iodotyrosine 4. Secretion of thyroidhormone (proteolytic enzymes) 5. Regulation by thyroidstimulating hormone( Tsai, T4, T3 of thy
Metabolism of thyroid hormones 1. Uptake of iodide 2. Activation of iodide (peroxidase), and iodination and coupling of tyrosine 3. Formation of thyroxine (T4 ) and triiodothyronine (T3 ) from iodotyrosine 4. Secretion of thyroid hormones (proteolytic enzymes) 5. Regulation by thyroid stimulating hormone (TSH),T4 , T3
Acute Circadian and psychosis pulsatile rhythms Severe Cold stress H Hypothalamus Somato @statin Corticoids Regulation of the secretion dopamine of thyroid hormones AP (feedback inhibition) TA.T TSH② Thyroid
Regulation of the secretion of thyroid hormones (feedback inhibition)
Pharmacology of thyroid hormones o 1. Normalizing growth and development u 2. Promoting body metabolism Body temperature; energy levels, ect. d 3. Enhancing sympathetic activity
1. Normalizing growth and development 2. Promoting body metabolism Body temperature; energy levels, ect. 3. Enhancing sympathetic activity Pharmacology of thyroid hormones
Clinical uses of thyroid hormones u 1. Treatment of hypothyroidism u Hypothyroidism 1. 8% of total population Incidence increases with age 2-3% of older women More common in females
1. Treatment of hypothyroidism Clinical uses of thyroid hormones Hypothyroidism 1.8% of total population. Incidence increases with age. 2-3% of older women. More common in females
Etiology PRIMARY HYPOTHYROIDISM Hoshimoto' s thyroiditis-most common Irradiation of thyroid Su urgical removal Late stage invasive fibrous thyroiditis Iodine deficiency Drug therapy lithium) Infiltrative diseases Sarcoidosis, amyloidosis Scleroderma hemochromatosis
Etiology PRIMARY HYPOTHYROIDISM Hoshimoto’s thyroiditis-most common Irradiation of thyroid Surgical removal Late stage invasive fibrous thyroiditis Iodine deficiency Drug therapy (Lithium) Infiltrative Diseases: Sarcoidosis, Amyloidosis Scleroderma, Hemochromatosis
SECONDARY HYPOTHYROIDISM o of cases Pituitary or hypothalamic neoplasm Congenital hypopituitarism Pituitary necrosis(Sheehan's syndrome)
SECONDARY HYPOTHYROIDISM 5% of cases. Pituitary or hypothalamic neoplasm. Congenital hypopituitarism. Pituitary necrosis (Sheehan’s syndrome)
Common signs and symptoms Cretinism: a situation induced by a insufficiency of thyroid hormone at birth and during minority, execute growth, twined facial features, increased tongue and mental detainment Adult Fatigue, weakness, weight gain, cold intolerance Coarse, dry hair, dry and rough pale skin, hair loss Muscle cramps and frequent muscle aches Constipation(便秘) Depression Memory loss Abnormal menstrual cycles, decreased libido
Common signs and symptoms Cretinism: a situation induced by a insufficiency of thyroid hormone at birth and during minority, execute growth, twined facial features, increased tongue and mental detainment Adult: Fatigue, weakness, weight gain, cold intolerance Coarse, dry hair, dry and rough pale skin, hair loss Muscle cramps and frequent muscle aches Constipation(便秘) Depression Memory loss Abnormal menstrual cycles, decreased libido
Myxedema describes a specific form of cutaneous and dermal edema secondary to increased deposition of connective tissues as seen in various forms of hypothyroidism
Myxedema describes a specific form of cutaneous and dermal edema secondary to increased deposition of connective tissues, as seen in various forms of hypothyroidism
Thyroid Hormone replacement Levothyroxine(左甲状腺素) is commonly used It can cause increases in resting heart rate and blood pressure So replacement should start at low doses in older and patients at risk for cardiovascular compromise Myxedema Coma Below normal temperature, decreased breathing, low blood pressure, low blood sugar, unresponsiveness Hydrocortisone, T3(fast
Thyroid Hormone Replacement Levothyroxine (左甲状腺素) is commonly used It can cause increases in resting heart rate and blood pressure So replacement should start at low doses in older and patients at risk for cardiovascular compromise Myxedema Coma Below normal temperature, decreased breathing, low blood pressure, low blood sugar, unresponsiveness Hydrocortisone, T3 (fast)