أسئلة_الـ_14_باثو_PPPM_قبل_التعديل

• Circulatory disturbances covered are hyperaemia, edema and hemorrhage.

Hyperaemia

• Increased blood in a vessel.
• Can be active or passive.

Active (Arterial) Hyperaemia

• Increased blood flow to an organ as a result of active dilation of arterioles and capillaries.
• Active due to changes in the muscle tone of vessels.
• Physiological causes include muscular exercise, glands during secretion, or emotional flushing.
• Pathological causes include acute inflammation.

Passive Hyperaemia (Venous Congestion)

• Increased venous blood in an organ due to obstruction of venous outflow.
• Passive because there is no muscle tone in the veins and capillaries.

General Venous Congestion

• Generalized congestion affects the entire body due to total heart failure; it can be acute or chronic.
• Localized congestion affects a part of the body caused by venous outflow obstruction; it can be acute or chronic.

Acute General Venous Congestion

• Acute heart failure causes acute congestion in all organs.

Chronic General Venous Congestion

• Gradual venous congestion affects the whole venous system.
• Causes include right-sided and left-sided heart failure.
• Right-sided heart failure results in venous congestion all over the body, except the lungs.
• Left-sided heart failure results in venous congestion of the lungs.

Pathology of Right-Sided Heart Failure

• General effects include congested neck veins, cyanosis, and cardiac edema.
• Local effects manifest in organs such as the liver, spleen, and kidneys.
• Congested neck veins occur due to dilatation of the vena cava and systemic veins accommodating more blood.
• Cyanosis results from bluish coloration of lips and nails due to increased reduced hemoglobin, decreased oxygenation, and inadequate tissue perfusion.
• Cardiac edema involves the accumulation of serous fluid (transudate) in interstitial spaces.

Chronic Venous Congestion of Liver

• Early stages (Nutmeg Liver):
  • Enlarged in size but preserves the shape.
  • Smooth surface with a stretched capsule and soft consistency.
  • Mottled appearance with dark red areas of congestion alternating with yellow fatty changes.
  • Rounded borders.
  • Central veins and ends of sinusoids are dilated and congested.
  • Central hepatocytes undergo necrosis due to pressure from congested sinusoids.
  • Mid-zone hepatocytes show fatty changes.
  • Peripheral hepatocytes are either normal or show cloudy swelling.
  • Kupffer cells contain haemosiderin granules.
• Late stages (Cardiac Cirrhosis):
  • Liver is shrunken and has lost its shape.
  • Granular surface with an adherent capsule that is hard to remove.
  • Firm consistency with a whitish color due to fibrosis.
  • Sharp borders.
  • Central hepatocytes undergo necrosis followed by fibrosis.
  • Fibrosed areas join to form fibrous bundles.
  • Compensatory proliferation of healthy hepatocytes produces regenerating nodules.

Chronic Venous Congestion of Lungs (Brown Induration)

• Causes include chronic left ventricular failure and mitral stenosis.
• Blood accumulates in the left atrium, then pulmonary veins, venules, and alveolar capillaries, leading to congestion, dilation, and pulmonary edema.
• Blood in the capillaries ruptures, and released hemoglobin is ingested by macrophages, which causes fibrosis.
• Some heart failure cells return to the interstitial tissue, leading to fibrosis in the lung.
• The lung becomes brown and tough, a condition known as "Brown induration".

Local Venous Congestion

• Localized congestion in a body part due to local venous obstruction.

Acute Local Venous Obstruction

• Characterized by sudden complete venous obstruction.
• Causes include thrombosis, ligature, and strangulated hernia.

Chronic Local Venous Obstruction

• Characterized by gradual incomplete venous obstruction.
• Causes include compression by tumors, enlarged lymph nodes, pregnant uterus, or liver cirrhosis with fibrosis.

Edema

• Abnormal accumulation of excess fluid in interstitial tissue spaces or body cavities.
• Fluid resides outside cells and vascular structures.

Types of Edema

• According to etiology: inflammatory or non-inflammatory.
• According to distribution: local (due to inflammation, venous congestion, or lymphatic obstruction) or generalized (due to heart failure, chronic renal failure, or liver disease).

Pathophysiologic Mechanisms of Edema

• Increased blood hydrostatic pressure.
• Decreased plasma colloidal osmotic pressure.
• Lymphatic obstruction.
• Sodium retention.
• Increased vascular permeability.

Terminology for Edema

• Pitting edema: A depression or dent remains after applying pressure due to excess interstitial fluid being forced to adjacent areas.
• Anasarca: Severe generalized edema with swelling of the subcutaneous tissues.
• Hydrothorax (Pleural Effusion): Fluid in the thoracic cavity.
• Hydropericardium (Pericardial Effusion): Fluid in the pericardium.
• Hydroperitonium (Ascites): Fluid in the peritoneal cavity.

Hemorrhage

• Escape of blood outside the cardiovascular system.

Causes of Hemorrhage

• Trauma.
• Spontaneous causes include diseases or destruction of the vascular wall, or systemic diseases like hemorrhagic diathesis, Vitamin C and K deficiency, and hypertension.

Types of Hemorrhage

• External Hemorrhage (outside body):
  • Epistaxis: Bleeding from the nose.
  • Hemoptysis: Coughing of blood from the lung.
  • Hematemesis: Vomiting of blood from the esophagus, stomach, or duodenum.
  • Melena: Digested blood in stool, originating from the stomach or duodenum.
  • Bleeding per rectum: Undigested blood in stool, originating from below the duodenum.
  • Hematuria: Blood in urine.
  • Menorrhagia: Prolonged heavy menstrual bleeding.
  • Metrorrhagia: Irregular uterine bleeding not related to menstruation.
• Internal Hemorrhage (Within Tissue & Serous Sacs):
  • Hemothorax: Hemorrhage into the pleura.
  • Hemopericardium: Hemorrhage into the pericardium.
  • Hemoperitonium: Hemorrhage into the peritoneum.
  • Hemarthrosis: Hemorrhage into a joint cavity.
  • Hematocele: Hemorrhage into the tunica vaginalis.
• Into the Tissue (Interstitial Hemorrhage):
  • Petechiae: Small, pinpoint hemorrhages (1-2 mm).
  • Purpura: Slightly larger hemorrhages (3-5 mm).
  • Ecchymosis: Larger hemorrhages (1-2 cm), also known as hematomas (bruises).