Blood and Its Components
Are you familiar with blood? Many of you will, but how exactly can we describe it? In simple words, it's that red substance that seeps out when you get a paper cut. But exactly what does it do? Let’s go through the document to have a better understanding of blood and its importance.
Blood is a fluid that flows throughout the body within blood vessels. Blood is essential for life, because it carries oxygen and nutrients to organs and tissues, and helps eliminate waste. In addition, blood helps fight infections and heal from injuries. Red blood cells, white blood cells, platelets, and plasma are some of the parts of blood that make up blood.
From which Substances is Blood Made of?
The four components of blood are:
Red Blood Cells (RBS’s)
White Blood Cells (WBS’s)
Platelets or Thrombocytes
Plasma
Now let’s discuss them one by one.
Red Blood Cells
They are the most numerous cells in the blood.
They are responsible for transporting oxygen from the lungs to the rest of the tissues.
The protein inside that binds oxygen is called haemoglobin.
Haemoglobin is red and gives this color to blood.
White Blood Cells
They are also called leukocytes.
They deal with defending the body against the attack of bacteria, viruses, parasites and fungi.
Platelets
To stop bleeding, platelets work with clotting proteins.
Per microliter of blood, there should be between 150,000 and 400,000 platelets.
Plasma
It is the liquid part of the blood.
This liquid transports the different types of blood cells to all parts of the body.
Plasma carries proteins called "clotting factors" that help platelets to form clots.
The composition of blood is shown in the figure below:
Composition of Blood
Blood Functions
By explaining its components, we have already advanced some of its basic functions. Among them stand out:
Transport oxygen to the tissues and transport carbon dioxide from the cells to the lungs to be eliminated abroad.
Transport the energetic substances that the organism needs.
Defend the body against agents that are harmful to health, preventing the onset of infections or diseases and/or mitigating their effects.
Perform tissue healing and coagulation processes.
The color of the blood is undoubtedly its most characteristic quality. Red and blood are two strongly associated concepts to the point that the color red is strongly linked to the representation of violence, war, health, or other concepts linked to the liquid that circulates through our veins and arteries.
Summary
The components of blood are made up of two parts, one is liquid and the other is cellular. The liquid is the plasma. And the cellular part has three types of cells. These are red blood cells, white blood cells, and platelets. The main function of red blood cells, or erythrocytes, is to transport oxygen from the lungs to the body's tissues and carbon dioxide as a waste product from the tissues to the lungs. Hemoglobin (Hgb) is an important protein in red blood cells that carries oxygen from the lungs throughout the body.
FAQs on Blood and Its Four Components
1. What are the four main components of blood and their functions?
Blood is composed of four primary components, each with a specific function:
- Plasma: This is the yellowish, liquid part of the blood that makes up about 55% of its volume. It carries blood cells, nutrients, hormones, and waste products throughout the body.
- Red Blood Cells (RBCs): Also called erythrocytes, these cells contain haemoglobin, which transports oxygen from the lungs to the body's tissues and carries carbon dioxide back to the lungs.
- White Blood Cells (WBCs): Known as leukocytes, these cells are a key part of the immune system. They protect the body against infections and diseases by identifying and destroying foreign invaders like bacteria and viruses.
- Platelets: Also called thrombocytes, these are small cell fragments that help in blood clotting. When a blood vessel is injured, platelets gather at the site to form a plug and stop the bleeding.
2. Why is blood red in colour?
The characteristic red colour of blood comes from a protein called haemoglobin, which is found in abundance within the Red Blood Cells (RBCs). Haemoglobin contains iron atoms, and when these atoms bind with oxygen in the lungs, they give the blood its bright red appearance. Deoxygenated blood is a darker shade of red.
3. What is the main function of White Blood Cells (WBCs)?
The main function of White Blood Cells (WBCs) is to act as the body's defence system. They identify and fight off germs, such as bacteria, viruses, and other foreign particles that enter the body. They are essential for preventing and combating infections and are a crucial part of our immune system.
4. What is the importance of platelets in our blood?
Platelets are vital for preventing excessive blood loss. Their primary importance is in the process of blood clotting. When you get a cut or an injury that damages a blood vessel, platelets rush to the site, stick together to form a temporary plug, and release signals that start a chain reaction to form a stable clot, which seals the wound and allows it to heal.
5. What is the difference between blood components and blood types?
It's a common point of confusion, but they refer to different things:
- Blood Components are the actual physical parts that make up the blood. These are the plasma, red blood cells, white blood cells, and platelets.
- Blood Types (like A, B, AB, and O) are a classification system. This system categorises blood based on the presence or absence of specific inherited substances, called antigens, on the surface of red blood cells.
In short, components are what blood is made of, while types are how we classify it for safe transfusions.
6. Why do our veins appear blue through the skin if blood is always red?
The blue appearance of veins is an optical illusion. Blood is never blue. This effect happens because of how light interacts with your skin and tissues. Blue light does not penetrate the skin as deeply as red light. When light hits your skin, the red wavelengths are mostly absorbed by the tissue, while the blue wavelengths are reflected back to your eyes, making the deeper veins look bluish.
7. Besides the four main components, what else is transported in our blood?
Beyond the four main components, the blood plasma is a carrier for many other essential substances required for the body to function. These include:
- Nutrients: Such as glucose, amino acids, vitamins, and minerals absorbed from the digestive system.
- Hormones: Chemical messengers that travel from glands to target organs.
- Waste Products: Such as urea and carbon dioxide, which are transported to the kidneys and lungs for removal.
- Antibodies: Proteins that help fight infection.
8. What would happen if our blood did not have platelets?
If a person's blood lacked a sufficient number of platelets, their body would lose the ability to form blood clots effectively. This condition, known as thrombocytopenia, would be extremely dangerous. Even a minor cut, scrape, or bruise could lead to severe and prolonged bleeding that is difficult to stop, potentially resulting in significant blood loss from a small injury.
