Blood, Components of blood and Blood Groups:
What is blood?
- Blood is a transport fluid which is pushed by heart in the whole body to distribute oxygen and important It also collect carbon dioxide back to heart that is a type of waste material.
- Blood cells are formed in bone marrow that is soft and spongy material present in the center of the bones.
What are different functions of Blood?
- Nutrition transport: It transports oxygen and nutrients to every cell of the body.
- Gas transport: It also take carbon dioxide back to lungs to get rid of it.
- Coagulation of blood: It contains some substances that help to coagulate the blood.
- Removal of waste products: It helps to carry waste products to liver and kidney so the body can get rid of it.
- Protective function: It contains antibodies that makes the immune system strong.
- Thermoregulation: It regulates the body temperature.
- Regulation of different processes:
- It also transports hormones to the target organs.
- It also carries buffers that maintain the pH.
- Osmotic function: It maintains osmotic pressure in blood vessels.
- Detoxification: Blood enzymes split different toxic substances.
Is blood a tissue?
- Blood is a connective tissue, composed of two parts:
- Plasma (liquid part)
- Blood cells: Red blood cells, White blood cells, platelets.
Components of plasma in blood
Yellowish- liquid containing:
- Water 95%
- Soluble proteins: fibrinogen, prothrombin, antibodies.
- Dissolved mineral salts as ions: potassium, sodium and calcium.
- Variables: products of digestion, vitamins, excretory products, hormones.
- Dissolved gases: oxygen and carbon dioxide
- Red blood cells or Erythrocytes.
- White blood cells or leukocytes.
- Platelets or thrombocytes.
Formation of Red Blood Cells
Structure of a Red Blood Cell
How does a Red Blood Cell work?
White blood cells or leukocytes.
Platelets or thrombocytes:
- Smallest cells of blood.
- Cell fragments enclosed by a membrane.
- Lack nucleus.
- Platelets produce in bone marrow (spongy-like tissue)
- Life-span between 5-9 days.
- These cells play major role in blood coagulation and wound healing.
- Platelets and damaged blood vessels at the wound release an enzyme known as thrombokinase which results in the production of
- Thrombin acts on the plasma protein – (soluble protein)
- Fibrinogen is converted into fibrin (insoluble protein) which forms a network of fibres like sieve.
- These become clogged with red blood cells.
- Stops further blood loss and stop harmful germs entering the body.
Red cells trapped in a fibrin network
The defense against infection by pathogens
- Blood groups are named after the antigens present on red blood cells of every individual.
- Red blood cells are covered by millions of antigens present on their membrane.
- An antigen can be any substance to which immune system respond.
- Antibodies are produced by WBCs (B lymphocytes) and used by immune system to identify and attack any foreign substances.
- Antibodies are present in blood plasma.
- Blood group Antigens are ignored by immune system but antigens of any other blood group will always be recognized as foreign particles and attacked by antibodies.
- There are four blood groups – A, B, AB and O.
- Antigens are represented by capital letters A and B
- Antibodies may be represented by small letters a and b
- The table below shows the antigens and antibodies present in the different blood groups:
- What happens when different blood groups are mixed?
Agglutination or blood clumping occurs
- What is the difference between positive and negative blood groups?
In some blood groups a protein RH factor is present on red blood cells called RH positive (positive blood groups) for example, O positive, A positive, AB positive etc.
And sometimes RH factor is absent on red blood cell so it is RH negative.
- Are all the blood antigens protein?
No blood antigens are either protein or sugar. For example antigens of ABO are sugars while antigens of RH blood group are proteins.
- What is immunization?
It is the process of production of antibodies in against of antigens.
- What is the difference between serum and plasma?
When blood clots, a yellowish liquid called serum is left behind, serum has the same composition as plasma except that it lacks the clotting factors.
- Which component of the blood makes the most of the volume of human blood?
Plasma is the most abundant substance in blood.
Red blood cells come on second number.
- What is the ratio of RBCs and WBCs?
- What is the life span of RBCs?
- What is the life span of WBCs?
Approximately 20-30 days
- Who is responsible for secreting thromboplastin?
Thromboplastin is secreted by platelets during the process of coagulation.
- What are the main components of blood?
- What is another name of red blood cells?
- What is another name of white blood cells?
- What is another name of platelets?
- What do you mean by agglutination?
- What is the difference between granulocytes and agranulocytes?
- Why red blood cells have no nucleus?
- Why are red blood cells red in colour?
- Where are red blood cells formed?
- What is plasma?
- Which are the cells responsible for making antibodies?
- What is the difference between antigens and antibodies?
- What is the difference between fibrinogen and fibrin?
- What is phagocytosis?
- Name the biggest WBC?