Introduction
The human body is something that has always fascinated scientists all around the world and even us. Whether we walk, run, dance, eat, or sleep, every work has something to do with the muscles of our body. These muscles are made up of tissues, which are nothing but a cluster of cells working together to perform certain functions.
Four kinds of tissues are present in the human body: Epithelial Tissue, Muscle Tissue, Nervous Tissue, and Connective Tissue. Out of all of these, let's understand what Connective Tissue is.
Connective Tissue, as the name connects the term "connect" has some sort of function to do with our body's connection with its various tissues or organs. There are various kinds of connective tissue present in our body, among which an easy example would be blood.
Blood is an important fluid that helps in transporting necessary substances, which include nutrients and oxygen, to various parts of the human body. Besides that, it also carries deoxygenated blood to the lungs for purification and to supply oxygenated blood to the entire body. It also helps in carrying out toxins from our body.
Blood is mainly composed of four components- Red Blood Cells (RBCs), White Blood Cells (WBCs), Plasma, and Platelets.
RBCs (Red Blood Cells) – Also known as Erythrocytes, they are just bright red-colored cells which is present in large amount in our body, and that's why the blood appears red. It consists of a protein called hemoglobin, which is responsible for carrying oxygen and carbon dioxide from the lungs to the body and vice versa.
WBCs (White Blood Cells) – Also known as Leukocytes, are responsible for protecting the body from any infection.
Platelets – Also known as Thrombocytes, are responsible for clotting function. Whenever we have a cut, it is the work of platelets to gather at the area of injury and clot the flow of blood.
Plasma – It's a fluid component of the blood that transports water, nutrients, hormones, waste materials, and many more throughout the body.
Now, Plasma and Blood are one of those topics which can be tricky to understand, so let us go through them with more clarity.
Blood vs. Plasma
As stated earlier, Blood is a kind of fluid that helps to supply necessary substances throughout our body. Those substances may include nutrients, water, oxygen, hormones, etc. It consists of four components: RBCs, WBCs, Platelets, and Plasma. It consists of 55% of plasma and 45% of blood cells. Blood also consists of a certain type of iron-containing protein known as haemoglobin, which is responsible for carrying oxygen as well as carbon dioxide from and to the lungs in the entire circulatory system of the body, and it also gives a red color to it.
Plasma is the fluid component of blood, which consists of about 92% water, 7% of it is vital proteins like albumin, gamma globulin, and anti-hemophilic factor, and 1% of minerals, salts, fats, vitamins, sugar, and hormones. It is the largest part of blood, which is of straw yellow color. It has the responsibility to carry water, nutrients, hormones, enzymes, etc. throughout the body. Plasma is also responsible for getting rid of all the waste material produced in the body, which is dumped into it by the cells. Nowadays, plasma donation is also done to treat patients with trauma and serious injuries. The donated plasma is frozen within 24 hours of donation so that its important components can be preserved and is known as FFP (Fresh Frozen Plasma). Hospitals can store this for more than a year and can use it for treating patients whenever needed.
| Properties | Blood | Plasma |
| Definition | Blood is a type of fluid connective tissue responsible for carrying valuable substances in the entire body. | Plasma is a component of blood that covers 55% of the entire blood volume. |
| Color | It is red in color. | It is straw-yellow in color. |
| Components | Haemoglobin | Water, valuable proteins, salts, minerals, sugars, vitamins, enzymes, hormones, and fats. |
| Haemoglobin | It doesn’t contain haemoglobin. | It doesn’t contain hemoglobin. |
| Presence of cells | Blood does contain cells. | Plasma doesn't have any kind of cells. |
Now that we know the basic difference between blood and plasma let's understand these two topics in more detail.
What is Blood?
Whenever we have a cut in any part of our body a red color fluid comes out from that cut mark, that fluid is known as blood. Blood is a type of connective tissue more appropriately a fluid connective tissue that almost covers 7-8% of our total body weight (it is an approximate value it may vary according to a person's gender, location, and other factors). This connective tissue helps in transporting nutrients, oxygen, carbon dioxide, water, hormones, waste materials, etc. in the entire human body. It contains three types of cells Erythrocytes, Leukocytes, and Thrombocytes along with a fluid-like thing known as Plasma. It runs in the entire body via veins, arteries, and capillaries. 55% of blood is plasma, and the remaining 45% is cells.
The main function of blood includes-
- Carrying oxygenated blood from the lungs to various parts of the body along with many nutrients, water, and complex chemical substances required by the cells for its proper functioning.
- It also carries deoxygenated blood from various parts of the body to the lungs via veins for its purification along with waste product that is needed to be dumped out of the body.
- Regulates the temperature of the body and maintains the pH, too.
- Since it has WBCs and Platelets, it also helps in fighting any possible infection that can harm our body and also causes coagulation of blood when we have any sort of cut to prevent blood loss.
The Types of Blood
Blood donation is a popular campaign performed in various places. People donate blood so that hospitals can make use of it to cure patients who need it. According to WHO (World Health Organisation), about 118.5 million blood donations are collected globally. Now, while donating blood an adult human can donate about 1 pint of blood, which is about 10% of the total amount of blood in the body, which is quite safe. But the fact is that not everyone's blood is the same; it varies from person to person.
Blood is mainly categorized into four types which are known by the name Blood Group; these blood groups are A, B, AB, and O. It's not the end here; these blood groups again may or may not contain a certain type of protein known as Rh factor which gives positive [+] or negative [-] labeling to it, i.e. A+/ A-; B+/ B-; AB+/ AB-; O+/ O-, the donated blood is then categorized accordingly.
| Blood Groups | A | B | AB | O |
| Red blood cell type | A | B | AB | O |
| Type of Antibody | B | A | None | A and B |
| Type of Antigen | A | B | A and B | None |
(Antigens are foreign bodies that make our immune system produce Antibodies, and these Antibodies fight against those Antigens.)
- Blood Group A: The people having A blood group can receive blood from people having type A or O and can donate to type A or AB. They have antibodies of type B and antigens of type A.
- Blood Group B: The people of blood group B can receive blood from people of type B or O and can donate to type B or AB. They have antibodies of type A and antigens of type B.
- Blood Group AB: The people of blood group AB can receive blood only from those who have blood type AB and can donate to AB only. They do not have any antibodies and have antigens of type A and B.
- Blood Group O: The people of blood group O can receive blood only from those who have blood type O and can donate to any ABO blood group. They have antibodies of type A and B but do not have any antigens.
The table below represents the Donor and the Recipient of various blood types-
| Recipient/Donor | A+ | A- | B+ | B- | AB+ | AB- | O+ | O- |
| A+ | Y | Y | N | N | N | N | Y | Y |
| A- | N | Y | N | N | N | N | N | Y |
| B+ | N | N | Y | Y | N | N | Y | Y |
| B- | N | N | N | Y | N | N | N | Y |
| AB+ | Y | Y | Y | Y | Y | Y | Y | Y |
| AB- | N | Y | N | Y | N | Y | N | Y |
| O+ | N | N | N | N | N | N | Y | Y |
| O- | N | N | N | N | N | N | N | Y |
(Y is for yes, and N is for no.)
Thus, we can conclude that O- is the universal donor while AB+ is the universal recipient.
What is Plasma?
Plasma is one of the most essential components of blood. Just like RBCs, WBCs, and Platelets have an important role to play, Plasma helps these cells to travel in the entire body. It covers up about 55% of the entire volume of the blood and thus is the largest part of blood, and it is of straw-yellow color. It is a mixture of 92% water, 7% vital proteins like albumin, gamma globulin, and anti-hemophilic factor, and 1% of minerals, salts, fats, vitamins, sugar, and hormones. It has a density of about 1025 kg/m^3. Cells usually dump the waste products in the plasma, and then plasma removes that waste from our body. It also helps in carrying nutrients, water, minerals, enzymes, and complex chemical substances throughout the body. Plasma seems to be transparent fluid where the cells are suspended freely.
FFP, i.e., Fresh Frozen Plasma, is a technique of storing donated plasma that can be used later for treating patients with serious injuries, trauma, etc. The blood plasma is collected by centrifuging the donated blood, which has an anticoagulant that, in the end, brings the cells to the bottom and plasma above it in the vessel. Later, this plasma is stored and labeled accordingly by its type. Just like in the earlier case of blood not everyone can have any type of blood same goes for plasma too. There is certain compatibility for it, which is represented below-
| Recipient / Donor | A | B | AB | O |
| A | Y | N | Y | N |
| B | N | Y | Y | N |
| AB | N | N | Y | N |
| O | Y | Y | Y | Y |
(Y is for yes, and N is for no.)
Since type AB doesn’t possess any type of antibody, let it be A or B, and that’s why it can donate plasma to any category but can receive only from AB. Similarly, type O has both kinds of antibodies, which is why it cannot donate plasma to anybody but O and can also receive plasma from any kind of blood group at the same time.
Main Difference Between Blood and Plasma in Points
- Blood is a fluid connective tissue, while plasma is the fluid component of blood.
- Blood is red, whereas plasma is straw-yellow.
- RBCs, WBCs, Platelets, and Plasma are the main components of blood, while the components of plasma include water, protein, fats, vitamins, minerals, enzymes, hormones etc.
- Blood has haemoglobin; Plasma doesn’t contain haemoglobin.
Conclusion
It can be concluded that Blood has four components, out of which Plasma constitutes 55% of its volume, and the remaining is covered up by the cells. Blood is nothing but a kind of tissue that helps in the proper functioning of the body. The cells present in the blood are suspended freely in the plasma, which then, along with various other nutrients, circulates throughout the entire body. Plasma is only a straw-yellow color fluid of the blood. Both blood and plasma are stored in various hospitals for emergency purposes for treating patients.
