Krvinky

Krvinky is a Czech term used in everyday speech to refer to the cells that circulate in blood. In formal scientific contexts, the precise terms are erythrocytes for red blood cells and leukocytes for white blood cells; platelets are also considered part of the cellular components of blood. The word krvinky can be used to refer to blood cells in general, but it is not a formal scientific category.

Red blood cells, or erythrocytes, are the most numerous blood cells. In mammals they are disc-shaped and typically lack a nucleus, and they contain hemoglobin, which binds oxygen and carbon dioxide. Their primary function is gas transport. They are produced in the red bone marrow by erythropoiesis and usually live about 120 days in humans. Dying cells are removed mainly in the spleen and liver.

White blood cells, or leukocytes, are part of the immune system and defend against infections. They include granulocytes (neutrophils, eosinophils, basophils) and agranulocytes (lymphocytes, monocytes). They originate in bone marrow and lymphoid tissues and have varying lifespans and functions, including phagocytosis, antibody production, and immune signaling.

Platelets, or thrombocytes, are small fragments derived from megakaryocytes that participate in blood clotting and wound repair. They circulate for about 7–10 days in humans and are cleared by the spleen.

Species differences exist; for example, red blood cells in non-mammals retain a nucleus. The term krvinky is most often used in Czech-language medical education and consumer health information to refer to the cellular components of blood.