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

ANATOMY, PHYSIOLOGY, PATHOLOGY

SECTION 4. THE BLOOD SYSTEM

PATHOLOGY OF THE BLOOD SYSTEM

QUANTITATIVE CHANGES IN BLOOD

An increase in the circulating Blood volume is referred to as hypervolemia, whereas a decrease is called hypovolemia. If the ratio between formed elements and plasma shifts toward an increase in cellular components (erythrocytes), such hypervolemia or hypovolemia is termed polycythemic. If plasma predominates, it is termed oligocythemic.

Polycythemic hypervolemia occurs as a compensatory phenomenon under conditions of Hypoxia in high-altitude residents, as well as in pulmonary diseases and Congenital Heart defects. The highest erythrocyte counts are reached in true polycythemia, or erythremia—a neoplastic blood disorder driven by the hyperplasia of the Bone Marrow erythroid Lineage.

Oligocythemic hypervolemia develops following the transfusion of blood substitutes (such as polyglucin, reopolyglucin, etc.) and in ACUTE RENAL FAILURE during the oligoanuric stage.

Polycythemic hypovolemia is observed during dehydration resulting from vomiting, diarrhea, or diabetes insipidus.

Oligocythemic hypovolemia occurs after acute Hemorrhage, once the blood volume begins to restore through the shift of interstitial fluid into the vascular bed.

Quantitative Changes in the white blood lineage involve leukocytes and platelets. The blood leukocyte count may increase (leukocytosis) or decrease (leukopenia). An increase in the platelet count is termed thrombocytosis, while a decrease is called thrombocytopenia.

Plasma alterations are most commonly caused by an increase in its protein content (hyperproteinemia) or a decrease (hypoproteinemia); changes in the protein ratios and the COMPOSITION OF THE Proteins themselves are referred to as dysproteinemia.

Pathology of the blood system encompasses a broad group of diverse disorders. However, the greatest clinical significance belongs to anemias, neoplastic diseases (hemoblastoses), thrombocytopenias, and thrombocytopathies.



Last update: 08/08/2026

Editorial and Educational Adaptation: This material has been compiled based on the primary/original source text. The project team performed an editorial review, corrected technical inaccuracies, structured sections, and adapted the content for an educational format.

What was processed:

  • elimination of formatting defects (OCR errors, structural breaks, corrupted characters);
  • editorial organization of content;
  • standardization of terminology in accordance with academic sources;
  • verification of factual statements against the original source text.

All mentions of the author, publication year, and origin of the primary text have been preserved in accordance with the source.