Neurohypophysis

Suprarenal gland

the medulla has dual supply from both the cortical arteriole and the medullary arteriole.

physio

formation of glucose from Non-carbohydrate substances

(this is imp in young ppl, and that's why elderly will have low lean body mass & more adipose tissue)

Anti-Insulin effect

Severe snoring due to obstruction of the upper airway

because of increase of binding protein.

The most important mechanism is through PTH .(How)? ●1.25-Dihydroxycholecalciferol or calcifrol takes a place through PTH. ●Low calcium stimulates PTH release and PTH is going to mediate the process of calciferol formation

• * PTH has a slower effect ,its effect peak in 3-4 hours and it is less important in young individuals than calcitonin because their growth turn over.

• also act on the stomach to inhibit gastric emptying , and on the brain's satiety center to induce loss of appetite.

cortisol enzymes

• Glucocorticoids released by the adrenal cortex include: 1- Hydrocortisone: Commonly known as cortisol, it regulates how the body converts fats, proteins, and carbohydrates to energy. It also helps regulate blood pressure and cardiovascular function 2- Corticosterone: This hormone works with hydrocortisone to regulate immune

• in renal epithelial cells cortisol will be converted to cortisone by an enzyme called 11β-hydroxysteroid dehydrogenase type 2 ( cortisone has minimal binding to that receptors )

Features of Addison disease

• If the disease is secondary ( in hypothalamus or pituitary) , there will be no Excess secretion of ACTH , so there will not be Hyperpigmentation feature.

pharma

T3 or T4.

Iodide:

Insulin therapy

• Sulfonylureas work on a receptor close to K+ channels on the B-Cells of the pancreas, inhibiting these channels, causing depolarization, allowing the entry of calcium to the cell, which gets the granules to fuse to the cell membrane to secrete insulin.

• *sulfonylureas are the 2nd line oral diabetic agents, given when Metformin has failed to control the glucose levels, and when the patient is underweight or at least not obese.

• What pharmacologists also did is develop DPP4 inhibitors, and the advantage of these DPP4 inhibitors over Exanetide are that DPP4 inhibitors are given orally and not in subcutaneous injections.

Injecting ACTH for diagnosis

Glucocorticoids receptors are widely distributed through the body while mineralocorticoids receptors are only limited to certain organs , particularly the kidney and other excretory organs like the sweet glands and the salivary ones, so mineralocorticoids just regulate the processes of electrolytes and fluid transport while Glucocorticoids have a much wider role in the body.

• Aldosterone is not the main regulator for sodium reabsorption , the ACTH and rennin-angiotensin II systems are the main regulator .

spironolactone

So in the replacement therapy, the basic concept is to start with Hydrocortisone, if the patient is having a sustained salt wasting, then you might need to add the Fludrocortisone. (The mineralo-mimetic drug is only added if Hydrocortisone is not sufficient to stop the salt wasting).

corticosteroids

Side effect of corticoids

• So imagine a pregnant woman who has asthma, it's almost always these patients will develop gestational diabetes, because you have to use corticosteroids in these patients if they have sever flares of the disease.

patho

CLINICAL FEATURES of PITUITARY ADENOMA :

2-Growth hormone secreting adenoma

thyroid

Usually decreased TSH levels are associated with increased free T4 levels ,, however in some patients we might see ,increased T3 but normal or decreased freeT4 ,,[T3 toxicosis]

Subacute Granulomatous Thyroiditis: [de Quervain thyroiditis]

Graves disease

# toxic multinodular goiter: type of multinodular goiter that manifest with thyrotoxicosis secondary to the development of autonomous nodules that produce thyroid hormone independent of TSH stimulation

Thyroid Neoplasms • Investigations include:

ADENOMAS

MEDULLARY CARCINOMA

Primary Hyperparathyroidism

Genetic abnormalities

Diabetes

Diabetes type 2

Biochem

Actions of thyroid hormones

They stimulate the synthesis of a number of hormones and enzymes. One such enzyme is cytochrome c oxidase, a part of the electron transport chain. The ETC is found in the inner mitochondrial membrane, and its function is ATP synthesis. An increasein thyroid hormone will lead to an increase in ATP production, and since ATP production is associated with heat production patients with hyperthyroidism will suffer from heat intolerance.

1) Iodide trapping: The first stage in the formation of thyroid hormones is transport of iodides from the blood into the thyroid gland. This is an active process that requires energy. In the basal membrane there is a sodium/potassium ATPase pump that creates a sodium concentration outside the cell. A sodium iodine symporter then carries the iodide (along with sodium) into the follicular cell.

2) Oxidation of Iodide: This is conversion of the iodide ions to an oxidized form of iodine. Iodide ion is converted to I2 that is capable of combining directly with tyrosine. Oxidation of iodide is catalyzed by peroxidase/hydrogen peroxide system

Organification: The binding of iodine to the tyrosine residues of the thyroglobulin molecule is called organification of the thyroglobulin.This process is catalyzed by the enzyme iodinase

Under normal condition 70% of tyrosine residues of thyroglobulin are in the form MIT and DIT and 30% as thyroxine (T4) (only a minor part is in the form of T3)

*Propylthiouracil (PTU) inhibits peroxidase enzyme as well as coupling of iodinated tyrosine residues(Steps 2&4), that’s why it can be used in the treatment of patients with excessive thyroid function. In the figure PTU is the thioamide.

1) As a result of TSH stimulation, follicular cells will extend pseudopods. These pseudopods will entrap a part of the colloid making an endosome (pinocytic vesicles). The process by which this happens is called pinocytosis. The endosome contains thyroglobulin.

4) Most of the MIT and DIT are recycled back into the colloid. Their iodine is cleaved by deiodinase enzyme that makes iodine available for making thyroid hormones.