Hemodynamic Pathology Part 1

Study Notes

Edema: Excess fluid accumulation in the extracellular matrix.
Hyperemia: Increased blood flow to a tissue.
Congestion: Accumulation of blood in a particular area.
Hemorrhage: Loss of blood from the circulatory system into surrounding tissues (extravasation).
Hemostasis: Physiological process that stops blood flow after vascular injury.
Thrombosis: Formation of a blood clot within the blood vessels.
Infarction: Local tissue death due to obstructed blood supply.
Shock: Condition of circulatory failure or collapse.

Function of Capillaries: Essential for delivering oxygen/nutrients and removing metabolic wastes from tissues.
Starling Forces: Pressure mechanisms that dictate fluid movement across capillary membranes.
- Hydrostatic Pressure: Pushes fluid out of capillaries (higher at arterial end).
- Oncotic Pressure: Pulls fluid into the capillaries (higher at venous end).
- Lymphatic Circulation: Helps remove excess fluid from tissues.

Edema: Fluid accumulation in tissues.
Effusions: Fluid accumulation in body cavities.
Two fluid types:
- Inflammatory: Protein-rich exudates from increased vascular permeability.
- Non-inflammatory: Protein-poor transudates typically due to systemic issues like heart or liver failure.

Increased Hydrostatic Pressure: Can result from impaired venous return, such as in deep vein thrombosis (DVT) or congestive heart failure.
Reduced Plasma Osmotic Pressure: Due to low protein levels from liver disease, malnutrition, or losses in nephrotic syndrome.
Sodium and Water Retention: Causes increased hydrostatic pressure and decreased vascular osmotic pressure due to expanded intravascular volume.
Lymphatic Obstruction: Results from trauma, infections, or neoplastic conditions that impede lymph drainage.
Inflammatory Edema: Occurs due to increased vascular permeability leading to fluid leakage.

Localized vs. Generalized:
- Localized: Includes inflammatory edema, lymphatic edema, and pulmonary edema.
- Generalized: Examples include cardiac edema, nutritional edema (hypoproteinemia), and renal edema.
Pitting vs. Non-pitting:
- Pitting Edema: Leaves a depression when pressed (indicates conditions like right-sided heart failure).
- Non-pitting Edema: No depression occurs (common in lymphatic obstruction).
Transudate vs. Exudate:
- Transudate: Protein-poor fluid, typically seen in hydrodynamic derangements.
- Exudate: Protein-rich fluid associated with inflammation.

Gross Features: Characterized by swelling, heaviness, and pallor in affected tissues.
Microscopic Features: Includes separation in the extracellular matrix and subtle cell swelling.
Subcutaneous Edema: Often influenced by gravity, appearing in areas such as the legs after prolonged standing; pitting edema may be evident when pressure is applied.