Main Difference – Human Blood vs Animal Blood
Blood is the body fluid that transports substances such as nutrients, oxygen, and metabolic wastes to their destinations in the body. It is composed of blood cells and plasma. Red blood cells, white blood cells, and platelets are the cellular component of the blood. Human blood varies from animal blood due to multiple factors. The main difference between human blood and animal blood is that human blood comprises hemoglobin as its respiratory pigment whereas animal blood may consist of some other types of respiratory pigments as well. Based on the type of respiratory pigment present in the blood, different types of blood have different colors.
Key Areas Covered
1. What is Human Blood
– Definition, Components, Respiratory Pigment
2. What is Animal Blood
– Definition, Components, Respiratory Pigment
3. What are the Similarities Between Human Blood and Animal Blood
– Outline of Common Features
4. What is the Difference Between Human Blood and Animal Blood
– Comparison of Key Differences
Key Terms: Animal Blood, Blood Grouping System, Human Blood, Platelets, Red Blood Cells, Respiratory pigments, White Blood Cells
What is Human Blood
Human blood is the body fluid that circulates through the heart and blood vessels of the circulatory system, carrying oxygen and nutrients to body cells and removing metabolic wastes from the body cells. Moreover, human blood circulates inside a closed circulatory system. It contains 55% of plasma and 45% of blood cells. Red blood cells, white blood cells, and platelets are the cellular component of the human blood. Blood plasma serves as the extracellular matrix of the fluid. Oxygen transport occurs by means of hemoglobin, the respiratory pigment. Hemoglobin has a bright red color in the oxygenated state (arterial blood) and a dark red color in the deoxygenated state (venous blood). Neutrophils, eosinophils, basophils, lymphocytes, and monocytes are the five type of white blood cells, which fight against pathogens in the circulation as well as inside the tissues. Platelets are important for blood clotting. A human blood sample is shown in figure 1.
Figure 1: A Human Blood Sample
A antigen, B antigen, D antigen, and major histocompatibility (MHC) antigens occur on the surface of red blood cells in humans. A, B, and D antigens determine the type of blood while MHC antigen determines the tissue type. A, B, AB, and O are the four blood groups in humans. Human blood is divided into two categories based on the Rhesus antigen: Rh positive and RH negative.
What is Animal Blood
Animal blood refers to the fluid, which carries oxygen, nutrients and metabolic wastes throughout the animal body. Vertebrates and very few invertebrates consist of a closed circulatory system. Insects, crustaceans, mollusks, and other invertebrates have an open circulatory system. Animals with a closed circulatory system have blood. Their blood is composed of blood cells such as red blood cells, white blood cells, and platelets, and plasma. The size of the red blood cells widely varies among animals. Red blood cells of mammals lack a nucleus and organelles. They may have four types of respiratory pigments: hemoglobin, haemerythrin, haemocyanin, and chlorocruorin.
All vertebrates except fish, and some invertebrates have hemoglobin. Marine invertebrates such as sipunculids, brachiopods, priapulids, and annelids such as Magelona contain haemerythrin. Haemerythin is violet to pink in color when oxygenated and is colorless when deoxygenated. Haemocyanin is found in animals with an open circulatory system. These animals have hemolymph rather than blood. Haemocyanin occurs in the hemolymph. It is blue in color when oxygenated and colorless when deoxygenated. Thereupon, the respiratory pigments freely occur in the body fluid apart from cells. The cells in the hemolymph are called hemocytes. Hemocytes possess an immune function. The underside of a red rock crab is shown in figure 2. The purple color is given by hemocyanin. Annelids and marine polychaetes have chlorocruorin, which is red in color when oxygenated and is green in color when deoxygenated.
Figure 2: Purple Color on the Underside of a Red Rock Crab
White blood cells and platelets are similar in most animals. But, the proportions of each cell types may vary among animals. Some animals like fish have four types of white blood cells. The adhesion of platelets during blood clotting may vary in animals. Horse blood has the most adhesive platelets. Mammals and birds are warm-blooded animals.
Reptiles, amphibians, fish, and invertebrates are cold-blooded animals. All animals have A and B antigens in their red blood cells. Animals such as cattle, horses, cats, and dogs may have other antigens as well. Human-type and simian-type are the two types of blood grouping systems found in monkeys and apes. These animals have unique blood grouping systems. DNA testing is the most precise method to distinguish between mammal’s blood.
Similarities Between Human Blood and Animal Blood
- Most human blood and animal blood are composed of blood cells and plasma.
- Most human blood and animal blood are composed of red blood cells, white blood cells, and platelets as their cellular component.
- Platelets of both human blood and animal blood lack nuclei.
- Both human blood and animal blood have A and B antigens.
- Both human blood and animal blood comprise different types of respiratory pigments for the transportation of oxygen.
- The main function of both human blood and animal blood is to transport nutrients, oxygen, and metabolic wastes to their destinations.
Difference Between Human Blood and Animal Blood
Definition
Human Blood: Human blood is the body fluid that circulates through the heart, arteries, capillaries, and veins and is the main means of transport within the human body.
Animal Blood: Animal blood is the fluid that carries oxygen, nutrients and metabolic wastes throughout the animal body.
Open/Closed Circulatory System
Human Blood: Humans have an open circulatory system.
Animal Blood: Animals have either an open or closed circulatory system.
Blood Cells
Human Blood: Red blood cells, white blood cells, and platelets are the cellular components of the human blood.
Animal Blood: Most animals comprise red blood cells, white blood cells, and platelets. Animals with a closed circulatory system comprise hemocytes.
Blood Group
Human Blood: Humans comprise ABO blood group and Rh blood group.
Animal Blood: Animals comprise different blood groups.
Respiratory Pigments
Human Blood: Hemoglobin is the respiratory pigment of humans and other vertebrates.
Animal Blood: Hemoglobin, haemerythrin, haemocyanin, and chlorocruorin are the four types of respiratory pigments in invertebrates.
Respiratory Pigment Occurrence
Human Blood: Respiratory pigments occur in red blood cells.
Animal Blood: Respiratory pigments occur outside the cells in animals with a closed circulatory system.
Blood Color
Human Blood: Human blood is red in color.
Animal Blood: Red, blue, green, and pink are the colors of the blood in animals.
Temperature
Human Blood: Humans have warmblood.
Animal Blood: Animal blood can be either warm or cold.
Red Blood Cell Antigens
Human Blood: A, B, and Rhesus antigen are the three types of antigens present in the red blood cells of humans.
Animal Blood: Red blood cells of animals may contain different types of antigens.
Red Blood Cell Nucleus and Organelles
Human Blood: Humans and other mammals do not have a nucleus and organelles in red blood cells.
Animal Blood: Animals other than mammals have a nucleus and organelles in red blood cells.
White Blood Cells
Human Blood: Humans have five types of white blood cells.
Animal Blood: Different animals have different types of white blood cells.
Conclusion
Humans and other animals consist of blood, which is a body fluid, transporting oxygen, nutrients, and metabolic wastes throughout the body. Blood is composed of blood cells and plasma. Human blood is red in color due to the presence of oxygen. Hemoglobin, hemerythrin, hemocyanin, and chlorocruorin are the four types of respiratory pigments in animals. In addition, different animal blood consists of different types of blood-borne antigens as well. The main difference between human blood and animal blood is the components of each type of blood.
Reference:
1. Human Blood: Blood Components, Palomar College, Available here.
2. Orwig, Dylan Roach and Jessica. “No, not all blood is colored red.” Business Insider, 21 Jan. 2016, Available here.
3. “Blood types.” EClinpath, Available here.
Image Courtesy:
1. “Ics-codablock-blood-bag sample” By ICSident at German Wikipedia (CC BY-SA 3.0) via Commons Wikimedia
2. “Hemocyanin Example” By Jerry Kirkhart – originally posted to Flickr as Hemocyanin Example (CC BY 2.0) via Commons Wikimedia
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