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Circulatory Disturbances

Circulatory Disturbances. HYPERAEMIA AND CONGESTION. Increased volume of blood in a particular tissue 1- Hyperaemia : Active process Local increase of blood to an organ due to active dilatation of arterioles and capillaries. Tissue is redder due to increase of oxygenated blood

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Circulatory Disturbances

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  1. Circulatory Disturbances

  2. HYPERAEMIA AND CONGESTION • Increased volume of blood in a particular tissue • 1- Hyperaemia: • Active process • Local increase of blood to an organ due to active dilatation of arterioles and capillaries. • Tissue isredder due to increase of oxygenated blood Examples • i- Skeletal muscle during muscular exercise (Physiologic) • ii- Acute inflammation (Pathologic)

  3. 2- Congestion • Passive process • Resulting from impaired outflow from a tissue • It may be generalized: cardiac failure or localized resulting from venous obstruction • Veins, venules and capillaries in the organ are passively dilated • Tissue has a blue- red color (cyanosis) due to accumulation of deoxygenatedblood

  4. Types of congestion 1- LOCAL VENOUS CONGESTION • 1- Acute venous congestion Sudden occlusion of a vein by thrombus, ligature or strangulation. - Effects: oedema and haemorrhage 2- chronic venous congestion: Gradual and incomplete venous obstruction resulting from :Pressure by tumor , enlarged lymph node, pregnant uterus or Liver cirrhosis

  5. Pathology and Effects: - Oedema (since capillary bed congestion leads to increase fluid transudation). - Haemorrhage due to capillary rupture; breakdown and phagocytosis of the red cell. - Stasis predisposes to thrombosis and causes hypoxia, which can result in parenchymal cell degeneration or death. - Gradual opening of collaterals - Development of varicose (thickening, dilatation, elongation and tortuosity of the chronically congested veins or vein collaterals).

  6. Varicose veins

  7. b- General venous congestion • The obstruction is central (heart or lung). All, the venous return is obstructed. 1. Acute general venous congestion: Causes: Acute heart failure Effects: Rapid generalized congestion of organs & generalized oedema. 2. Chronic general venous congestion: Gradual venous congestion affecting the whole venous system Causes: It is caused by right ventricular heart failure due to chronic obstructive lesions affecting the heart, the pulmonary vessels and the lung

  8. . • General effects: • 1. Dyspnea • 2. Hypoxia and cyanosis caused by reduced oxygenation of blood in the congested lungs; in addition, increased amount of reduced haemoglobin. • 3. Cardiac oedema: Generalized oedema caused by the right sided heart failure. - Sites: Oedema appears first around the ankles (gravity effect) then gradually become generalized and may involve the peritoneum (ascites), pleura and pericardium. • 4. Local congestion of lung, kidney, liver, spleen, stomach, intestine and some viscera

  9. Congestion of the lung Over filling of the neck vein reduced arterial supply to tissue Inferior vena cava Back pressure right or let sided heart failure hepatic congestion Splenic congestion Renal congestion distension of leg veins

  10. OEDEMA:Abnormal and excessive accumulation of fluids in the intercellular tissue space and/ body cavities • Fluids may be • 1-Exudate: due to increased vascular permeability, and the fluids have high specific gravity (>1.015)( high protein content )as in inflammation. • 2-Transudate: Results from unbalance in body fluids as in heart failure, the fluids have a specific gravity (<1.015) (lower protein content).

  11. Oedema

  12. Causes of Oedema: 1) Increased hydrostatic capillary blood pressure and so the fluids tend to move outside the vascular system. 2) Decreased osmotic pressure of the blood: due to hypoproteinemia 3) excess retained sodium ion and water → Increased osmotic pressure of the interstitial fluids. 4) Decreased power of lymphatics to drain excess fluids as in lymphatic obstruction. 5) Increased capillary permeability as in inflammation and hypersensitivity leads to escape of proteins in the oedema fluid. This will lower the plasma osmotic pressure.

  13. Types of Oedema 1- Localized oedema • Inflammatory oedema: Occurs in acute inflammation. • Obstructive oedema: -a-Venous obstruction: e.g. -Ankle oedema due to the pressure caused by enlarged uterus on the iliac vein. -Liver cirrhosis and bilharzial hepatic fibrosis cause intestinal oedema and ascitis. -b-Lymphatic obstruction: causes lymphatic oedema. It is caused by tumour or disease as elephantiasis.

  14. 2- Generalized Edema • i) Nutritional Edema • ii) Cardiac Edema • iii) Renal Edema

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