Normal Physiology TSH stimulates secretion of T4 and T3 from thyroid Most serum T3 produced by deiodination of T4 Think of T3 as active hormone and T4 as prohormone Only small fraction total T4 and total T3 is unbound – therefore free and active 10
TFTs TSH is the screening test of choice for thyroid function (nml 0.3-5mU/L) T4 T3 Antithyroglobulin (TSAb) 11
Evaluation of Thyroid Diseases 1.Clinical history and physical examination 2.Serum T3 & T4, TSH determination 3.Thyroid scan (RAIU) 4.Thyroid ultrasound 5.Plain x-ray, CT scan / MRI 6.FNAC 7.Sleeping pulse & laryngoscope. 12
Answer the following questions: (time allowed 5 minutes) A.Enumerate types of shock: B.Define: 1.Epistaxis: is……………………………………….. 2.Hemoptesis: is…………………………………... Good luck.
Congenital anomalies 1 Agenesis L-troxine Ectopic (along the line of descent) – Lingual at the foramen caecum, may be the only thyroid tissue, causes yellow swelling, dysphagia and bleeding. Treatment : L-troxine, excision and reimblantation. – Median ectopic in the upper 2/3 of neck, can be the only thyroid tissue. Treatment excision and reimplantation. Aberrant(away from the line of descent) – Median (larynx, trachea, intrathoracic) – Lateral(obsolete term, in LNs= metastasis) 15
Simple goiter Def : non inflammatory, non toxic, non neoplastic enlargement of thyroid gland. Etiology : ch. Decrease of thyroid hormone or rarely pituitary adenoma. – Decrease I2 – Decrease synthesis of hormones – Antithyroid drugs – Goitrogenic substances (cabbage, cauliflower) 18
Stress leads to dec. T3 & T4 increase TSH physiological goiter. I.Stress over --> normal gland II.Prolonged stress exhaustion of the gland diffuse colloid goiter and after time nodular colloid goiter. III.Stress repeated fibrosis simple multinodular goiter. 19
Treatment of simple goitre. Physiological L-troxine + I2 -> good response. Colloid rarely respond Nodular goiter never respond to medical treatment. Subtotal or total thyroidectomy followed by L- troxine. 20