Lymph is not actually called blood. While lymph is a fluid that circulates throughout the body, it is not the same as blood. However, they are closely related, and lymph is often described as "blood without red blood cells."
Lymph originates from blood plasma, which leaks out of blood vessels into tissues. This fluid, now called lymph, contains white blood cells (especially lymphocytes) and other substances, including fats and proteins. It travels through a network of lymphatic vessels, filtering through lymph nodes, before returning to the bloodstream.
Here's why lymph is considered similar to blood, but not the same:
- Both contain white blood cells: Both blood and lymph contain white blood cells, which are essential for fighting infections.
- Both circulate throughout the body: Both blood and lymph circulate throughout the body, though through different systems.
- Lymph is derived from blood plasma: The fluid that makes up lymph originates from blood plasma, which leaks out of capillaries.
However, there are key differences:
- Red blood cells: Blood contains red blood cells, which carry oxygen, but lymph does not.
- Transporting oxygen: Blood is responsible for transporting oxygen throughout the body, while lymph does not carry oxygen.
- Circulatory systems: Blood circulates through a closed system of blood vessels, while lymph flows through an open system of lymphatic vessels.
Therefore, while lymph shares some similarities with blood, it is a distinct fluid with a specific role in the body's immune system and fluid balance.
