Thyroid Disease Flashcards
What is the right and left thyroid united by
Isthmus
What are the functions of the thyroid hormones
Control of metabolism
Regulate growth + development
Describe the HPT axis
Hypothalamus secretes TRH
Pituitary secretes TSH
Thyroid secretes T4 and T3
Target tissue release T3 (negative feedback) = Act on pituitary & hypothalamus
What hormone is active and which hormone is most abundant
T3 = Active T4 = Most abundant
Describe the synthesis of thyroid hormones
TSH bind to TSHR on basolateral membrane
I- uptake by Na/I symporter
Thyroperoxidase bind I to tyrosine residues in thyroglobulin to form MIT & DIT
T4 = DIT + DIT
T3 = MIT + DIT
Export to colloid where it is stored
How do thyroid hormones travel in the serum
Thyroid binding proteins eg.
Thyroxine binding globulin
Albumin
What are the causes of hyperthyroidism
Graves Disease Toxic nodular goitre Thyroiditis Exogenous Iodine TSH secreting pituitary adenoma Neonatal hyperthyroidism
What are some of the signs and symptoms of hyperparathyroidism
Tachycardia Weight loss Double vision Starry eyes Clubbing
How do you diagnose hyperparathyroidism
Goitre Eye disease TPO Abs TSH Abs Measure TSH. If normal, rule out primary
What are the treatments available for hyperparathyroidusm
Thionamides = block hormone synthesis
Propylthiouracil = Inhibit TPO
Surgery = total thyroidectomy
Radio Iodine therapy = destroy thyroid tissue. Very effective
What are the complications for hyperparathyroidism
Cardiac disease
Decrease bone density
Graves opthamopathy
What is Graves Disease
Autoimmune Disorder
Pathogenic Abs to TSHR, TPO and Tg
How do you identify patients with Graves
High HR
Lid retraction
Periorbital puffiness
Goitre
What is neonatal hyperparathyroidism
TSHR Abs cross placenta so increased risk of chid getting hyperparathyroidism
What are the causes for hypothyroidism
Hashimoto's thyroiditis After treatment for hyperthyroidism Silent thyroiditis = inflammation of gland Congenital = causes cretinism I deficiency
