Components of Blood

Introduction

Blood is a liquid tissue made up with homogenous red fluid, the thin layer found to be a suspension of different types of cells in a liquid called “plasma”. Plasma contains a liquid called serum and other coagulable and anti-coagulable substances . When plasma cells circulate through the body supplies essential substances from digested food such as sugar, oxygen to the cells and organs. The blood corpuscles present in plasma are of two types-Red Blood Corpuscles (RBC) and White Blood Corpuscles (WBC).  The RBC is also known as “Erythrocytes’ ‘ and WBC are further classified as granulocytes and agranulocytes based on the structure of the nuclei and presence or absence of granules.

The components of Blood are:

1. Plasma
2. Red Blood Cells
3. White blood Cells
4. Platelets

Plasma

1. Plasma is a liquid component of blood which maintains a pH of 7.4. Human (animal) blood consists of a liquid (plasma) and a number of cellular and cell fragment components. The contents of plasma are about 60% of a volume of blood, cells and fragments are 40%. Plasma has 90% of water and 10% of dissolved material including proteins, glucose, ions, vitamins, fats and gases.
2. Percentage of plasma-in blood plasma occupies around 58% of  volume of blood (volume of the blood is 5L) 
3. Lifespan of plasma – short-lived plasma cells have a lifespan of 3-7 months whereas, long-lived plasma cells hold the life for 60 years. 
4. Role of plasma – the main function of plasma is to intake nutrition, hormones and proteins to the other parts of the body for providing energy. 

Importance of Plasma 

• Helps in maintaining blood pressure 
• Carries sodium and potassium to our muscles 
• Helps in maintaining proper pH balance in the body
• Improves cell functioning 

Red Blood Cells

Humans have a total of 25 trillion Red blood cells, and they are continuously manufactured in the bone marrow of long bones, ribs, skull and vertebrate. Red blood cells, also known as erythrocytes have slightly indented and flattened disk shape. They transport oxygen to and from the lungs.

RBC count(s) – Mature erythrocytes lack a nucleus, and they are small sizing around 4 – 6 million cells per cubic millimetre (in males 4.5 – 6.2 million and in female 4.0-5.2) of blood and have about 200 million haemoglobin molecules per cell. The cells are about 7 µm in diameter that carry oxygen associated in the cell’s haemoglobin. Haemoglobin is a protein that contains iron and carries oxygen to its destination.

Lifespan of the RBC – the lifespan of an erythrocyte is only 120 days, after which they are destroyed in the liver.

Iron atoms – each haemoglobin consists of 4 iron atoms, which binds the oxygen. Iron atoms from haemoglobin are recovered and reused by red marrow. The liver degrades the heme unit and secretes them as pigment in the bile, responsible for the colour of faeces.

White Blood Cells

1. White blood cells, also known as lymphocytes, it’s a type of blood cell that is made in the bone marrow and found in the blood and lymph tissue. They help the body fight infection and other diseases. They are larger than erythrocytes, have a nucleus and lack haemoglobin. They function in the cellular immune response. WBC are made up with less than 1% of blood content, forming vital defences against disease and infection.
2. Size of the WBC – WBC has an irregular shape and its size varies from 12-17 µm.
3. WBC count(s) – The number of WBC counts in a microfiber of blood usually ranges from 3700-10500.
4. Lifespan of the WBC – the lifespan of an WBC is only 12- 20 days, after which they are destroyed in the lymphatic system.
5. Immunity – Lymphocytes fight infection whereas; T cells attack cells containing viruses and B cells produce antibodies.

Platelets

1. Platelets are made in bone marrow along with your WBC and RBC. One of the remarkable properties of blood is its ability to clot or coagulate, when it is withdrawn from the body. Clot occurs as a response to tissue injury, such as muscle tear a cut, or a sharp blow. Platelets are tiny blood cells that help your body form clots to stop bleeding.
2. Lifespan of the platelets – platelets survive for 10 days being removed by the liver and spleen.
3. Platelets count – there are 1,50,00 to 3,50,000 platelets in each millilitre of blood.
4. Importance – platelets stick and adhere to tears in blood vessels, they also release clotting factors. A haemophiliac blood cannot clot. Providing correct proteins has been a common method of tearing haemophiliacs. It has also led to HIV transmission due to the use of transfusion and use of contaminated blood products.
5. Risk – the body faces serious issues when the platelets count falls less than 50,000. A low platelet count shall be called “thrombocytopenia”. 

Causes of low platelets – bone marrow produces platelets and the factors that decrease platelets production are:

• Viral infections 
• Hepatitis C or HIV 
• Radiation therapy 
• Heavy alcohol consumption 

Conclusion

Blood regulates functioning of the organs by pushing the blood around the body through nerves or a network of tubes to reach all the tissues and the system in place to ensure that this network can be repaired if damaged.

Also, blood is important liquid tissue for regulating the body’s pH, temperature, osmotic pressure  and removal of waste. It’s also a fluid medium called plasma. Plasma transports food, carbon dioxide and nitrogen wastes in dissolved form. Oxygen is carried by the red blood cells. Many other substances like salts, which are also transported by the blood are also transported by the blood. Blood such as RBC in the blood increases haemoglobin, WBC improves the immunity system, platelet breaks the blood flow by clotting, plasma consists of 90% of water. A person’s lifespan and immunity system are based on the presence and proper working of components of blood such as plasma, RBC, WBC, platelets. When either of the mentioned properties range changes there shall raise issues such as anaemia, leukaemia or cancer.