The thyroid gland produces thyroid hormones that regulate metabolism. The thyroid synthesizes and releases triiodothyronine (T3) and thyroxine (T4), which are influenced by TSH from the pituitary and regulated by the hypothalamus. Hyperthyroidism results from excessive secretion of T3 and T4 due to Graves' disease or toxic nodular goiter. Hypothyroidism slows metabolism due to decreased T3 and T4 from conditions like surgical removal or inflammation of the thyroid. Common thyroid tumors include benign adenomas and malignant papillary or follicular carcinomas. Thyroiditis is inflammation of the thyroid and can be acute from infection, subacute from viruses, or autoimmune

1. Thyroid gland
“the butterfly shape organ “

2.  Synthesis and release of thyroid hormones is
influenced by TSH from the pituitary.
 Two kinds of hormones are produce in the thyroid
gland triiodothyronine (T3) and thyroxine (T4).
 concern the regulation of the metabolic and oxidation
rates in all the tissues of the body except the brain.
 Hypothalamus - the highest control of thyroid
function.

3. Hyperfunction
 Hyperthyroidism - over-activity of the thyroid gland
results in excessive secretion of T3 and T4.
 Thyrotoxicosis is due to diffused toxic goiter (Grave’s
disease) or nodular toxic goiter, with single or multiple
nodules (adenomas) of the thyroid responsible for the
excessive T3 and T4 secretion.

4. Hypofunction
 Decresed T3 and T4 production leads to slowing down of
metabolism, and produces signs and symptoms that are
generally opposite those of thyrotoxicosis.
 Cretinism - a genetic defect or agensia of the gland.
 Myxedema – caused by the surgical removal or atrophy of
the thyroid due to inflammation (thyroiditis), tumor or
radiation among others.

5. Thyroid tumors
Adenomas – benign functional tumors/ nodules
Tumors can be studied with the use of Radioisotope scan
of thyroid
Papillary carcinoma and Follicular Carcinoma
most common type of thyroid cancers

6. Thyroiditis (Inflammation of
thyroid)
Three types
 Acute thyroiditis –due to infection with pus-forming
bacteria.
 Subacute thyroiditis- due to exposure to viral diseases
such as measles or mumps.
 Lymphadenoid goiter or hashimoto’s disease - most
common but is hardest to diagnose. considered an
auto-immune disorder, like grave’s disease