Study of blood | definition, and functions

The study of blood, also known as hematology, is a vital branch of medical science that focuses on understanding blood composition, functions, and disorders. This field plays a crucial role in diagnosing and treating diseases such as anemia, leukemia, and clotting disorders.

What is the Study of Blood?

The study of blood is known as hematology. It involves the examination of blood, blood-forming organs, and blood-related disorders. Hematology covers the analysis of various blood components such as red and white blood cells, platelets, and bone marrow cells, as well as the diagnosis and treatment of related conditions.

Medical professionals specializing in this field include hematologists and hematopathologists. They are highly trained to diagnose and manage diseases related to the blood and its components. Hematological tests are commonly used to detect conditions such as anemia, infections, hemophilia, blood clotting disorders, and leukemia.

Hematologists also focus on the lymphatic system and bone marrow, which play critical roles in blood cell production and immune function. They often assess and treat disorders involving the lymph nodes, spleen, thymus, and lymphoid tissues, all of which are essential for nourishing and supporting blood cells.

Anatomy and Functions of Blood

Blood is a specialized bodily fluid that performs vital tasks essential to life. It circulates throughout the body, delivering nutrients and oxygen to cells while removing waste products. Composed of several components, blood plays diverse roles in maintaining homeostasis, immunity, and overall health.

Anatomy of Blood

Blood consists of four major components:

Plasma

• Volume: 55% of total blood volume
• A yellowish fluid made up of 92% water, 7% essential proteins, and 1% dissolved substances (minerals, carbohydrates, lipids, hormones, and vitamins).
• Acts as a transport medium for nutrients, hormones, enzymes, and waste products.
  

Red Blood Cells (RBCs or Erythrocytes)

• Volume: 45% of total blood volume
  
• Disc-shaped cells are produced in the bone marrow, rich in hemoglobin.
  
• Transport oxygen from the lungs to body tissues and carry carbon dioxide back to the lungs for exhalation.
  

White Blood Cells (WBCs or Leukocytes)

• Volume: <1% of blood volume
  
• Various types of immune cells are produced in the bone marrow.
  
• Defend the body against infections, foreign invaders, and abnormal cells.
  
  

Platelets (Thrombocytes)

• Volume: <1% of blood volume (along with WBCs)
  
• Small, colorless cell fragments are produced in the bone marrow.
  
• Aid in blood clotting and wound healing by forming plugs in damaged vessels.

Functions of Blood

Blood performs several vital functions in the human body:

Transportation

• Oxygen Delivery: RBCs transport oxygen from the lungs to tissues.
  
  
• Nutrient Transport: Delivers nutrients like glucose, amino acids, and lipids to cells.
  
  
• Waste Removal: Transports carbon dioxide to the lungs and metabolic waste to the kidneys.
  
  
• Toxin Removal: The liver detoxifies harmful substances from the blood for excretion.

Regulation

• Temperature Control: Blood distributes heat and regulates body temperature through heat exchange at the skin’s surface.
  
  
• pH Balance: Maintains a stable blood pH (around 7.4) using buffer systems.
  
  
• Fluid and Electrolyte Balance: Regulates the balance of water and electrolytes such as sodium, potassium, calcium, and chloride.

3. Protection

• Immunity: WBCs recognize and fight pathogens such as bacteria, viruses, and parasites.
  
  
• Clotting: Platelets and plasma proteins form clots to prevent excessive bleeding from injuries.
  

Areas of Study in Hematology

Hematology focuses on the study of blood and its related disorders. It is broadly divided into four main areas:

1. Hemoglobinopathy
   

   This involves the study of abnormalities in the globin chains of hemoglobin. Common conditions include thalassemia (a disorder of red blood cell production) and sickle cell anemia.
   
   

2. Hematologic Malignancies
   

   These are cancers of the blood, bone marrow, and lymph nodes, such as leukemia, lymphoma, and myeloma. Diagnosis and treatment of these cancers are a key focus of hematologists.
   
   

3. Anemia

   Anemia refers to a deficiency in red blood cells or hemoglobin, leading to reduced oxygen transport in the body.
   
   

4. Coagulopathy
   

   This area deals with disorders affecting blood clotting, including conditions like arterial thromboembolism, deep vein thrombosis, and other bleeding or clotting abnormalities.

Top Universities Abroad for Haematology Courses

Many top-ranked universities across the UK, Ireland, Australia, Malaysia, and Europe offer specialized Haematology courses. Below is a simplified list of some of the best universities abroad offering Haematology programs.

• University of Cambridge – UK
  
  
• University College London (UCL) – UK
  
  
• The University of Sydney – Australia
  
  
• Trinity College Dublin – Ireland
  
  
• University of Liverpool – UK
  
  
• University of Galway – Ireland
  
  
• Sapienza University of Rome – Italy
  
  
• Universiti Putra Malaysia (UPM) – Malaysia
  
  
• University of Greenwich – UK
  
  
• Kingston University – UK
  
  

Subdisciplines of Hematology

Hematology is the study of blood and its disorders. It includes several important subdisciplines:

Hematology Oncology

Hematology is closely linked with oncology, the study of cancer. Hematologists often work with oncologists to diagnose and treat blood and bone marrow cancers such as leukemia and lymphoma in both adults and children.

Hematologists are usually board-certified doctors who have completed additional training in hematology. Their main role is to provide direct patient care, focusing on diagnosing and managing blood diseases, especially cancers.

Hematopathology

Hematopathologists are specialists trained in both anatomical and clinical pathology, with extra training in hematopathology. They study diseases of the blood, bone marrow, and organs that depend on blood cells—such as lymph nodes, spleen, and thymus.

They diagnose disorders of blood-forming tissues and lymphocyte-rich organs by examining blood and tissue samples under the microscope in the laboratory.

Hematology Tests

Several tests are commonly used to diagnose and monitor blood disorders:

Complete Blood Count (CBC)

The CBC is one of the most common blood tests. It helps detect anemia, infections, blood cancers, clotting problems, and immune disorders. The test measures:

• White Blood Cell count (WBC)
• Red Blood Cell count (RBC)
• Platelet count
• Hematocrit (HCT) — the volume of red blood cells
• Hemoglobin (HB) — the oxygen-carrying protein in RBCs
• Differential White Blood Cell count
• Red Blood Cell indices (various measurements)

Uses: Diagnosing anemia, certain cancers, infections, and monitoring blood loss or inflammation.

Platelet Count

Often part of the CBC, it helps diagnose and monitor bleeding or clotting disorders.

Coagulation Tests

• Prothrombin Time (PT)
• Partial Thromboplastin Time (PTT)
• International Normalized Ratio (INR)

Uses: Assess bleeding and clotting problems and monitor blood-thinning treatments.

Bone Marrow Biopsy

A test performed by hematologists to extract and examine bone marrow cells for diseases. It is not routine but important in certain diagnoses.

Other Tests

• Blood chemistry tests
• Blood enzyme tests

Common Hematological Disorders

Anemias

This condition is characterized by a decrease in red blood cells or hemoglobin, leading to reduced oxygen delivery to tissues.
Symptoms: Fatigue, weakness, pale skin, shortness of breath, dizziness, headache, cold extremities.

Types:

• Iron Deficiency Anemia: Caused by low iron intake or blood loss; most common type.
• Vitamin B12 Deficiency Anemia: Due to a lack of vitamin B12, essential for red blood cell production.
• Hemolytic Anemia: Premature destruction of red blood cells from genetic, autoimmune, or infectious causes.
• Aplastic Anemia: Bone marrow fails to produce sufficient blood cells.
  
  

Leukemias

Cancers of white blood cells cause the uncontrolled growth of abnormal cells.
Symptoms: Fatigue, fever, infections, easy bruising/bleeding, swollen lymph nodes, weight loss, bone pain.

Types:

• Acute Leukemias: Rapid onset requiring urgent treatment.
• Acute Lymphoblastic Leukemia (ALL): Affects lymphocytes.
• Acute Myeloid Leukemia (AML): Affects myeloid precursor cells.
  
• Chronic Leukemias: Slower progression, milder symptoms initially.
• Chronic Lymphocytic Leukemia (CLL): Affects lymphocytes.
• Chronic Myeloid Leukemia (CML): Affects myeloid progenitor cells; characterized by leukocytosis with immature granulocytes due to the Philadelphia chromosome mutation.
  

Lymphomas

Cancers of the lymphatic system (lymph nodes, spleen, thymus).
Symptoms: Swollen lymph nodes, fever, night sweats, fatigue, weight loss, itching, chest pain, or cough if lungs are involved.

Types:

• Hodgkin’s Lymphoma: Identified by Reed-Sternberg cells in lymph node biopsies.
• Non-Hodgkin’s Lymphoma: A diverse group with various subtypes.
  
  

Bleeding Disorders

Conditions causing excessive or prolonged bleeding due to clotting factor or platelet problems.
Symptoms: Easy bruising, frequent nosebleeds, heavy bleeding after injury or surgery, heavy menstrual bleeding.
Types:

• Hemophilia: Inherited deficiency of clotting factors VIII or IX.
• Von Willebrand Disease: Most common inherited bleeding disorder affecting platelet adhesion.
• Thrombocytopenia: Low platelet count leading to easy bleeding and bruising.

Key Takeaways

• The study of blood focuses on diagnosing and treating diseases affecting blood components like cells, hemoglobin, proteins, bone marrow, and platelets.
  
• Blood is made up of red blood cells (about 45%), white blood cells, platelets, and plasma (55%), with red blood cells transporting oxygen to tissues.
  
• The complete blood count (CBC) is a key test in the study of blood, used to detect anemia, clotting problems, blood cancers, immune disorders, and infections.

Did you find this blog informative? If so, please share your thoughts in the comments section below. Click here to contact us for more information on the study of blood. We would be happy to assist you with your queries.

Liked this blog? Read next: What exactly is ophthalmology? – Study of eye

FAQs

Question 1. What is the study of blood called?
Answer. The study of blood is called hematology. It involves understanding the composition, functions, and diseases related to blood.

Question 2. Which are the top universities offering hematology courses abroad?
Answer. Leading UK universities offering hematology or related courses include:

• University of Cambridge 
• University College London
• University of Liverpool
• University of Chester
• University of Westminster

Question 3. How many cells are in the blood?

Answer. Men have between 4.7 and 6.1 million red blood cells per microliter of blood.

Women have between 4.2 and 5.4 million red blood cells per microliter of blood.

Children’s blood contains 4.0 to 5.5 million red blood cells per microliter.

Question 4. Which blood cell count is the maximum in blood?

Answer. Red blood cells comprise most of the blood, accounting for approximately 40-45% of its volume.

Question 5. Which is the smallest blood cell?

Answer. Blood platelets are the smallest blood cells, measuring roughly 2 to 4 micrometers in diameter.

WRITTEN BY

Aastha

Sr. Content Writer

Aastha Arya is a Senior Content Writer at iSchoolConnect who writes about topics covering study abroad trends, exclusive news updates and prolific college courses. She has a 4-year of experience in this field and also likes to keep tabs on recent events, visa policy changes, and many other concerns that affect international students.

`