Differences between Blood and Plasma
Contents
Blood vs. Plasma
Blood is the fluid connective tissue that circulates throughout the body, delivering essential substances such as oxygen and nutrients to the cells.[1][2][3] Plasma is the liquid component of blood, in which the red blood cells, white blood cells, and platelets are suspended.[4][5] Whole blood consists of about 55% plasma and 45% cellular components.[5]
Comparison Table
| Category | Blood | Plasma |
|---|---|---|
| Composition | Contains plasma, red blood cells, white blood cells, and platelets. | Primarily water (about 92%) with dissolved proteins, salts, hormones, and waste products. |
| Primary Function | Transports oxygen, fights infection, enables clotting, and regulates body temperature. | Transports cells, nutrients, hormones, and waste products; maintains blood pressure and pH balance. |
| Color | Red, due to the presence of hemoglobin in red blood cells.[5] | Straw-colored or pale yellow. |
| Cellular Components | Contains red blood cells, white blood cells, and platelets.[4] | Does not contain cellular components.[5] |
| Volume in Body | Makes up about 7-8% of total body weight. | Constitutes approximately 55% of the total blood volume. |
| Key Proteins | Contains all proteins found in plasma, plus hemoglobin within red blood cells. | Contains albumin, fibrinogen, and globulins (antibodies). |
Key Distinctions
The fundamental difference between blood and plasma is the presence of cellular elements.[5] Whole blood is a complete tissue that includes red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes), all suspended in plasma.[4] These cells are responsible for many of blood's key functions. Red blood cells are vital for transporting oxygen from the lungs to the body's tissues and carrying carbon dioxide back.[4][3] White blood cells are a critical part of the immune system, defending the body against infection.[4] Platelets, along with clotting factors in the plasma, are responsible for hemostasis, the process of forming clots to stop bleeding.[4][3]
Plasma, in contrast, is the acellular liquid matrix of the blood. It is mostly water, which acts as a solvent for a variety of substances including proteins (like albumin, which maintains osmotic pressure, and fibrinogen for clotting), electrolytes, nutrients, hormones, and waste products. The primary role of plasma is to serve as a transport medium for the blood cells and these dissolved substances throughout the circulatory system. It is also crucial for maintaining blood pressure and regulating the body's pH.
Medical Applications
In medical practice, blood and plasma are often used differently. Whole blood may be transfused in cases of severe blood loss, such as in trauma or surgery, as it replaces all components of the blood simultaneously. However, it is more common for donated blood to be separated into its components. This allows for more targeted treatment; a patient may receive packed red blood cells for anemia, platelets for clotting disorders, or plasma for other conditions.
Plasma, often transfused as Fresh Frozen Plasma (FFP), is used to treat patients with liver failure, severe infections, or serious burns. It is also essential for patients who lack specific clotting factors. Furthermore, plasma can be processed to create various medical products, including immunoglobulins and albumin concentrate. While a person with type O negative blood is a universal donor for red blood cells, a person with type AB blood is a universal plasma donor because their plasma does not contain antibodies that could react with a recipient's blood cells.
References
- ↑ "oregonstate.education". Retrieved January 30, 2026.
- ↑ "byjus.com". Retrieved January 30, 2026.
- ↑ 3.0 3.1 3.2 "visiblebody.com". Retrieved January 30, 2026.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 "khanacademy.org". Retrieved January 30, 2026.
- ↑ 5.0 5.1 5.2 5.3 5.4 "geeksforgeeks.org". Retrieved January 30, 2026.
