Components of Blood, Biology Notes for SSC CGL

Blood is one of the most important fluids in the human body. It performs the functions of transporting oxygen and essential nutrients into the cells and also transporting metabolic wastes from the same cells. It is very essential for the survival of the human body. In this blog, we will be learning about the components of blood.

Components of Blood – Biology Notes for SSC CGL

lood is one of the most vital fluids in the human body, responsible for transporting oxygen, nutrients, hormones, and waste materials. For aspirants preparing for SSC CGL, SSC CHSL, Railways, and other government exams, understanding the components of blood is an important part of the General Awareness syllabus.

What are the Components of Blood?

Blood consists of four main components: Plasma, Red Blood Cells (RBC), White Blood Cells (WBC), and Platelets, each playing a vital role in maintaining the proper functioning and survival of the human body.

Component	Also called as	Function	Lifespan	Nucleus
Plasma	–	Transport medium	–	–
RBC	Erythrocytes	Oxygen transport	120 days	No
WBC	Leukocytes	Immunity	13–20 days	Yes
Platelets	Thrombocytes	Clotting	8–12 days	No

What is Plasma and what are its functions?

Plasma is the liquid component of blood and forms about 55% of total blood volume. It is pale yellow in color and mainly composed of water. Key facts about plasma are:

• 90% water and 10% solutes
• Contains proteins, hormones, nutrients, and waste
• Helps in maintaining blood volume

Functions of Plasma

• Maintains blood pressure
• Helps in clotting and immunity
• Maintains pH balance
• Supports homeostasis in the bod

What are Red Blood Cells (RBC) and their functions?

Red Blood Cells, also called erythrocytes, are responsible for transporting oxygen throughout the body. Key facts about RBC are:

• Disc-shaped cells
• Contain hemoglobin (iron-rich protein)
• No nucleus (except in camel and llama)
• Formed in bone marrow
• Lifespan: 120 days
• Destroyed in liver and spleen

Functions of RBC

• Transport oxygen from lungs to body cells
• Carry carbon dioxide back to lungs

What are White Blood Cells (WBC) and their role?

White Blood Cells, also known as leukocytes, are the defense system of the body. Key facts about WBC are:

• Have a nucleus
• Lifespan: 13–20 days
• Types:
  • Granulocytes
  • Agranulocytes

Functions of WBC

• Fight infections
• Protect the body from pathogens
• Provide immunity

What are Platelets and why are they important?

Platelets, also known as thrombocytes, play a crucial role in blood clotting. Key facts about platelets are:

• No nucleus
• Lifespan: 8–12 days
• Formed in bone marrow
• Destroyed in spleen

Functions of Platelets

• Help in blood clotting
• Prevent excessive bleeding
• Repair damaged blood vessels

What are Blood Groups and why are they important?

Blood groups are classified based on the presence of antigens on RBCs.

Blood Group	Can Donate To	Can Receive From
A	A, AB	A, O
B	B, AB	B, O
AB	AB	A, B, AB, O
O	All	O

Important Points

• Universal Donor → O Negative
• Universal Recipient → AB Positive
• Blood group system discovered by Karl Landsteiner

What are some important facts about Blood?

• Study of blood is called Hematology
• Hemoglobin contains iron
• Females generally have lower hemoglobin than males
• Anemia is caused due to low hemoglobin
• Vitamin K helps in blood clotting
• Heparin is a natural anticoagulant

What are Common Blood Disorders?

Some important blood-related disorders asked in exams include:

• Anemia – Low hemoglobin
• Leukemia – Cancer of white blood cells
• Hemophilia – Blood clotting disorder

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