Blut

Blut is the German word for blood. In biology, Blut refers to the circulatory fluid that transports oxygen and nutrients to tissues, removes carbon dioxide and wastes, and participates in immune defense and hemostasis. In humans and most vertebrates, Blut circulates within a closed network of vessels driven by the heart.

Blood consists of plasma, the liquid component, and formed elements. Plasma makes up about 55% of blood and contains water, proteins (including albumin and clotting factors), electrolytes, nutrients, hormones, and waste products. Red blood cells carry hemoglobin for oxygen transport; white blood cells defend against pathogens; platelets help blood clotting.

Blood serves multiple functions: gas transport, distribution of nutrients and hormones, regulation of pH and body temperature, immune protection, and coagulation. Blood type systems, such as ABO and Rh, determine transfusion compatibility. The circulatory system includes systemic and pulmonary circuits, and the average adult has about five liters of Blut.

Clinical aspects include routine blood testing, donation, and the treatment of disorders such as anemia, infections, leukemias, and thrombocytopenia. Management may involve transfusion, iron supplementation, chemotherapy, or bone marrow transplantation, depending on the condition. The study of Blut supports diagnosis, monitoring, and therapy across many medical specialties.