Exam revision

• usually congenital; delayed virilising adrenal hyperplasia is a variant of congenital adrenal hyperplasia. • Both are caused by a defect in production of androgens. • The defect is only partial in delayed virilising adrenal hyperplasia, so clinical disease may not develop until adulthood

21-hydroxylase deficiency 11beta- hydroxylase deficiency

Congenital Adrenal Hyperplasia (CAH) is a family of inherited disorders affecting the adrenal glands. Autosomal recessive (mutation on chromosome 6)

A noncancerous (benign) tumor of the pituitary gland, located at the base of the brain, produces an excess amount of ACTH , which in turn stimulates the adrenal glands to make more cortisol

Hypothyroidism is a condition in which the thyroid doesn’t make enough thyroid hormones.

Hyperthyroidism is a condition in which the thyroid makes too much of certain thyroid hormones.

Hashimoto disease, also known as Hashimoto thyroiditis.  This is an autoimmune disease and the most common cause of hypothyroidism. Graves’ disease.  This is also an autoimmune disease and the most common cause of hyperthyroidism

Primary hypothyroidism – when your thyroid gland becomes diseased and cannot produce sufficient hormones Subclinical hypothyroidism- early and mild form of hypothyroidism Secondary hypothyroidism – when your pituitary gland isn’t stimulating your thyroid to produce enough hormones.

Hashimoto’s thyroiditis

High TSH with low Free T4/T3 High Thyroid autoantibodies

Elevated TSH and Normal T4/T3 level

Low levels of T4/T3 with high level of TRH

Grave’s disease  Autoimmune disease caused by antibodies to TSH receptors Toxic multi-nodular goiter  Active multinodular goiter associated with hyperthyroidism. Thyroiditis subacute  Abrupt onset due to leakage of hormones  Follows viral infection

Measuring serum TSH

Hypothalamus: Thyrotropin- releasing hormone (TRH)  control of thyroid stimulating hormone (TSH) Pituitary: Thyroid stimulating hormone (TSH)  controls production of the thyroid hormones by binding to TSH receptors located on cells in the thyroid gland. Thyroid: triiodothyronine (T3) and thyroxine (T4)

 The function of the thyroid gland is to take iodine, found in many foods, and convert it into thyroid hormones: thyroxine (T4) and triiodothyronine (T3).  These cells combine iodine and the amino acid tyrosine to make T3 and T4. T3 and T4 are then released into the blood stream and are transported throughout the body where they control metabolism (conversion of oxygen and calories to energy).

Deficient parathyroid hormone secretion Inability to Make Active Parathyroid Hormone. Resistance to Parathyroid Hormone (pseudo-hypoparathyroidism).

Lack of PTH leads to decreased blood levels of calcium (hypocalcemia) and increased levels of blood phosphorus (hyperphosphatemia). There are no symptoms of too little parathyroid hormone other than the symptoms due to having a blood calcium that is too low.

Deficient PTH secretion without a defined cause (e.g. surgical injury) is termed Idiopathic hypoparathyroidism

Characterised by hypocalcemia (too low blood calcium levels) and hyperphosphatemia (too high blood phosphorus levels) But they are distinguished by the fact that they DO produce NORMAL parathyroid hormone.

Primary Secondary Tertiary

Generalized disorder resulting from excessive secretion of parathyroid hormone (PTH) by one or more parathyroid glands. It probably is the most common cause of hypercalcemia

parathyroid adenoma – 80% parathyroid hyperplasia – 15% parathyroid carcinoma – 1-2%

Occurs most commonly in advanced chronic kidney disease when decreased formation of active vitamin D in the kidneys and other factors lead to hypocalcemia and chronic stimulation of PTH secretion. Hyperphosphatemia that develops in response to chronic kidney disease also contributes