MEDICAL BIOLOGY, ANATOMY, HUMAN PHYSIOLOGY AND PATHOLOGY - Ya.I. Fedoniuk 2010

ANATOMY, PHYSIOLOGY, PATHOLOGY

SECTION 1. ORGAN. ORGAN SYSTEM. ORGANISM

CIRCULATORY DISORDERS

1. HYPEREMIA

1.2. VENOUS HYPEREMIA

Venous congestion (hyperemia) can be either systemic or local. Systemic venous hyperemia is observed in Heart Failure. It is characterized by cyanosis, i.e., a bluish discoloration of the Skin and mucous membranes, which is especially noticeable in the peripheral PARTS OF THE body (acrocyanosis) — the fingertips, Nose, and Lips. This type of cyanosis is accompanied by edema of the subcutaneous tissue of the trunk and limbs, as well as the accumulation of fluid in Body Cavities (ascites in the peritoneal cavity, hydrothorax in the pleural cavity, and hydropericardium in the pericardial cavity).

Local venous congestion occurs when venous Blood outflow is hindered due to the occlusion of a vein lumen (by a thrombus or embolus) or its external compression (by a ligature, tumor, or Connective Tissue proliferation). If venous stasis develops very rapidly, it may lead to necrosis accompanied not only by marked cyanosis but also by tissue infiltration with blood, resulting in the so-called

hemorrhagic, or congestive, infarction. Such infarctions can be observed when the lumen of mesenteric Veins is obstructed (leading to congestive infarction and intestinal gangrene). Gradual occlusion of major venous trunks may not have such severe consequences.