Understanding the most vital biology concepts at the class 10 level ensures a stronger base for students who plan to pursue medical science. The difference between blood and lymph is one of those basic concepts. However, it is important to understand the composition and functions of blood and lymph to acknowledge the differences between the two completely.
On reviewing Class 10 Previous Year Question Papers, one can note that differences, similarities, definitions, functions, and reasons constitute a larger part of the biology exam questions. The following article compares the two fluids and also provides definitions and functions.
What is Blood?
Definition: The constantly circulating, specialised body fluid in the circulatory system of vertebrates that delivers oxygen and nutrients to various body cells and carries away metabolic waste products from them is called blood.
It is a fluid connective tissue in our body and contributes significantly to the transportation of several substances from one part of the body to another.
Production of Blood
Blood cells are produced in the bone marrow. The bone marrow produces up to 95% of the body’s blood cells. Haemopoiesis or hematopoiesis refers to the continuous production of cellular constituents of blood in the bone marrow. It ensures replenishment as needed.
Composition of Blood
Blood contains several blood cells and proteins suspended in a liquid called plasma. The presence of cells and other structures makes the blood thicker than water.
The main components of blood are as follows:
- Red blood cells or erythrocytes
- White blood cells or leukocytes
- Blood platelets or thrombocytes
- Plasma
Some other components of blood are
- Glucose
- Hormones
- Proteins
- Mineral salts
- Fats
- Vitamins
Pathway of Blood In the Human Heart
It is essential to study the blood flow pathway to understand its functions. Blood flows in the following order through our hearts.
Body → inferior/superior vena cava → right atrium → via tricuspid valve → right ventricle → pulmonary arteries → lungs → pulmonary veins → left atrium → via mitral or bicuspid valve → left ventricle → via aortic valve → aorta → body → inferior/ superior vena cava.
Functions of Blood
In addition to its primary function of transportation of substances, blood has several other important roles to play. The main functions of blood are
- It regulates body temperature.
- It checks the water content of the cells.
- The blood maintains the pH by interacting with acids and bases.
- It prevents its loss from the body via a mechanism of clotting/ coagulation.
- It carries hormones, enzymes, nutrition, respiratory gases, proteins, and other substances to the respective parts of the body.
What is Lymph?
Definition: A colourless and clear fluid containing lymphocytes, the white blood cells, flowing in the lymphatic vessels is called lymph.
Lymph is a slightly alkaline coagulable fluid forming a major part of the lymphatic system. It is found in the lymphatic vessels and reaches out to various body cavities.
Production of Lymph
Lymph formation occurs when the interstitial fluid gets collected through tiny lymph capillaries located throughout the body. Thus, lymph is produced as the affluent of interstitial fluid. The colourless fluid is then transported via lymphatic vessels to lymph nodes. The lymph nodes are associated with cleaning and filtering lymph. It then flows into the lymphatic ducts. Finally, lymph empties into the left or the right subclavian vein and mixes back with blood.
Composition of Lymph
The components of lymph are as follows:
- The lymph plasma contains calcium, blood proteins, phosphorus in smaller amounts, and glucose in higher concentrations.
- Lymphoma plasma has globin proteins that serve as natural antibodies.
- Corpuscles of lymph are lymphocytes, which are typically leukocytes and amoeboid cells.
- It also has carbohydrates, creatinine, urea, chlorides, proteins, and nitrogenous substances.
- Water – 94%
Pathway of Lymph
The flow of lymph in the human body can be represented as follows:
Intercellular spaces containing interstitial fluids → Lymph capillaries → larger lymph vessels → afferent lymph vessels → lymph nodes → efferent lymphatic vessels → lymph ducts or trunks → two large ducts: right lymphatic duct and left thoracic duct → the right lymphatic duct drains into the junction of the right internal jugular and right subclavian veins. In contrast, the left thoracic duct drains into the junction of the right internal jugular and right subclavian veins.
Functions of Lymph
The main functions of lymph are as follows:
- It transports the white blood cells within the lymph nodes and bones.
- It assists in removing interstitial fluid from tissues.
- It fights against infectious bacteria.
- Maintains supply of nutrients to the body
- Gets rid of metabolic wastes from the tissue cells
- Regulates the composition of tissue fluid
- Absorbs digested fats and fat-soluble vitamins from the small intestine via lymphatic vessels
Difference Between Blood and Lymph
The differences and similarities between blood and lymph are amongst the most important biology concepts. It is important not just for CBSE class 10th exams but also for NEET. Students can check out the NEET Biology Syllabus to understand the value of the topic.
The following table enumerates the points of difference between blood and lymph based on various characteristics of the two.
Characteristics | Blood | Lymph |
Definition | A fluid connective tissue that plays a vital role in the circulatory system. | Lymph is a fluid passing through lymphatic vessels, forming an important constituent of the lymphatic system. |
Colour | It is a red-coloured fluid. | It is a colourless fluid. |
Primary Function | It participates in transporting nutrients, oxygen, hormones, carbon dioxide, wastes, and more. | It forms an integral part of the body’s defence as a part of the immune system. |
Composition | It comprises plasma, red blood cells, white blood cells, and platelets. | It contains plasma, lymphocytes, white blood cells, and fewer platelets. |
Red Blood Cells | Blood contains red blood cells. | Red blood cells are absent. |
Oxygen | Blood carries more oxygen. | It carries less oxygen. |
Proteins | It contains larger amounts of proteins. | It has smaller amounts of proteins in proportions somewhat different from the blood. |
Presence of Minerals | It has calcium and phosphorus. | It has a lesser amount of calcium and phosphorus in comparison to blood. |
Nutrient Supply | It supplies nutrients to different organs of the body. | Lymph transmits nutrients between the body’s tissues and the bloodstream. |
Speed of Flow | It flows fast in blood vessels in comparison to lymph. | The flow of lymph in lymphatic vessels is slow. |
Movement | Blood has double circulation in the body. It moves circularly. | The lymph moves in a single direction in the body. |
Clot Formation | Blood has fibrinogen that aids in the quick formation of clots at the injury site. | Lymph has lesser fibrinogen, and thus it clots slowly. |
Site of Purification | The kidney purifies the blood. | The lymph nodes purify the lymph. |
Ailments | Some blood diseases are:
|
Some lymph-related diseases are:
|
Similarities between Blood and Lymph
Despite several points of difference between blood and lymph, there are a few similarities between them.
- Both blood and lymph are types of circulatory fluids.
- They circulate in the body within vessels.
- The two fluids also have an immune function in the body.
- A system of capillaries joins together both the fluids.
Bottomline
Although there are a few similarities between blood and lymph, such as assisting in the transportation of various body nutrients, oxygen, minerals, and other important substances, there are several differences between the two. While blood is red, lymph is colourless. From a difference in their colours to functions, the two fluids significantly differ from one another. Although the composition of the two fluids is somewhat similar, it is not identical. The varying composition leads to major points of difference between blood and lymph in terms of their function. Students can check out NCERT Solutions for Class 10 Science to get the best understanding of answers related to blood and lymph.