Definition of Diabetes mellitus (DM)

= How the hormonal feedback mechanism act

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= How the hormonal feedback mechanism act
= How the hormonal secretion occurs
= Factors order the glands to secrete hormones.
• Feedback control, either negative or positive, is a fundamental feature of endocrine systems to maintain hormone levels.
Positive feedback: in case of hormone secretion (when low hormone levels are detected)
Negative feedback: in case of stop secretion, if exceed the normal level. Diabetes Mellitus (DM)

How does insulin decrease the blood glucose level ?
1. Increase the uptake of glucose by the cells.
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2. Glucose oxidation (glycolysis): release of energy stored in glucose by binding it with oxygen.
3. Glycogenesis: glucose conversion into glycogen for storage in liver.
4. Help the body to store glucose in muscles, fat cells → to be used later when the body needs
- on the opposite side: glucagon enhances release of glucose from glycogen (glycogenolysis) & Enhances synthesis of glucose (gluconeogenesis) from amino acids or fats.
 Thus, raising the blood glucose level.
Role of liver
- Excess glucose is stored in the liver in the form of glycogen, which serves as a ready reservoir for future use.
- When energy is required glycogen glycogenolysis (by glucagon) → glucose
- liver also produces glucose from fat & proteins (amino acids) → gluconeogenesis → glucose
Diabetogenic hormones (hormones that raise blood glucose level
1. Glucagon from alpha cells in pancreas ↑ Blood glucose level so between meals and during prolonged starvation it is responsible to regulate blood glucose level.
2. Catecholamines e.g. Epinephrine from the Adrenal medulla has the same action as glucagon where it promotes the liver to produce glucose by Glycogenolysis + Gluconeogenesis
3. Glucocorticoids (Cortisol) from Adrenal cortex
4. Growth Hormone from Anterior pituitary gland
5. Thyroxine/thyroid hormone from Thyroid gland
▪ Glucose is the primary source of energy and every cell need glucose for its function byproduct of digestion of carbohydrates
▪ Insulin binds to receptors on cell facilitate glucose uptake by the cell NB. Insulin defector defect in insulin receptor → hyperglycemia.
▪ When glucose increase in blood hyperglycemia so body try to compensate by absorbing water from cells to dilute concentration of glucose in blood so patient becomes thirsty, polyuria & glucosuria.
▪ Cell send signals to brain to express their need to glucose food intake increase.
▪ Body tries to compensate the need of cells to energy by breaking fat and protein resulting in ketone body formation which circulate in blood Ketoacidosis( in DM type 1)

Pathophysiology of DM:
Signs and symptoms:
▪ Diabetes mellitus may present with characteristic symptoms such as thirst, polyuria, blurring of vision, and weight loss.
1. Weakness & skinny
2. Polyphagia with loss of weight cells express their need for glucose → hungry
3. Polydipsia and polyuria
 D.t high plasma levels of glucose water moves out from the cells → dehydration → thirst.
4. Acetone smell from mouth breath due to formation of ketone bodies and ketoacidosis → the body try to compensate the need for energy by breakdown of fat & protein → ketone bodies. Blowing of vision
6. Non-ketotic hyperosmolar state
▪ In its most severe forms, ketoacidosis or a non-ketotic hyperosmolar state may develop and lead to stupor, coma and, in absence of effective treatment, death.
▪ Decreased uptake of glucose causes extracellular hyperglycemia & intra-cellular hypoglycemia

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