Human Anatomy and Physiology - I. V. Gayvoronsky 2011

Cardiovascular System
Hemorrhage

Bleeding, or hemorrhage, is the escape of Blood from The Vascular System into the external environment or Body Cavities. It most commonly results from mechanical trauma that tears a blood vessel. Less frequently, vessel wall damage may be caused by a tumor, tuberculosis, or other pathological processes. In some cases, bleeding occurs due to increased vascular permeability or impaired Blood Coagulation. Significant blood loss deprives the Brain and Heart of an adequate blood supply, which can be fatal to the victim.

Bleeding is classified into external and internal. External bleeding involves the loss of blood outside the body, whereas internal bleeding occurs within body cavities (such as the abdominal or thoracic cavities). Detecting internal bleeding can be quite challenging; however, A large accumulation of blood in these cavities can rapidly lead to death.

Depending on the type of damaged vessel, bleeding is categorized into arterial, venous, capillary, and mixed.

Arterial bleeding is characterized by the flow of bright red blood in a pulsing jet under high pressure. Hemorrhage from major Arteries can cause rapid death, making prompt emergency intervention critical.

In venous bleeding, dark blood flows in a continuous stream. The rate of blood loss is directly proportional to the diameter of the injured vessel. Venous bleeding is managed using the same measures as capillary bleeding. A pressure bandage significantly narrows the vascular lumen and promotes blood clot formation. Additionally, the injured limb should be elevated.

Capillary bleeding occurs when small Blood Vessels are damaged, causing blood to ooze across the entire wound surface. The volume of blood lost is typically minimal. First aid for capillary bleeding involves treating the wound edges with an alcohol-based iodine solution, covering the affected area with a sterile gauze pad, and applying a pressure bandage.