Tag: blood clotting

Questions Related to blood clotting

The blood does not clot inside the body because of 

  1. Oxygenation of blood

  2. Movement of blood

  3. Absence of active clotting factors in normal condition

  4. None of the above


Correct Option: C
Explanation:

In blood, platelets produce thromboplastin only at the site of injury and not in the normal condition which initiates the process of blood clotting. There is an another factor or protein called fibrinogen. When it makes contact with oxygen, it polymerizes to fibrin wires, creating a heap of fibrin wires, in which the various blood cells get caught, thus clogging the wound. Because all the oxygen in the blood is already bound to haemoglobin (red cells), it can't interact with the fibrinogen, thus cannot create a clot. Thus, the correct answer is option C.

Labile factor is associated with

  1. Blood coagulation

  2. Blood group

  3. Blood immunity

  4. Blood circulation


Correct Option: A
Explanation:

Coagulation (blood clotting) is a complex process that involves a positive feedback system. The factors involved are-
Factor I Fibrinogen
Factor II Prothrombin
Factor III Tissue Factor (Thromboplastin)
Factor IV Calcium
Factor V Labile factor, proaccelerin, Ac-globulin
Factor VII Stable factor, proconvertin
Factor VIII Antihaemophilic globulin (AHG), Antihaemphilic factor A 
Factor IX Christmas factor, plasma thromboplastin component
Factor X Stuart power factor
Factor XI Plasma thromboplastin antecedent
Factor XII Hageman factor
Factor XIII Fibrin stabilising factor
Vitamin K is essential for synthesis of factors II, VII, IX and X.
Their numbers represent the order in which they were discovered.

Which clotting factor has been rejected now?

  1. VIII

  2. VII

  3. VI

  4. V


Correct Option: C
Explanation:

Clotting factor VIII is the antihemophilic factor while factor VII serves as an accelerator of serum prothrombin conversion. Clotting factor V is proaccelerin. Clotting factor VI was once considered to have clotting function but is now rejected. Thus, the correct answer is C. 

Which is unrelated to blood coagulation?

  1. Fibrinogen

  2. Fibrin

  3. Bilirubin

  4. Calcium


Correct Option: C
Explanation:

One of the initial steps in blood coagulation is the release of thromboplastin that interacts with other clotting factors and calcium ions. Fibrinogen is a soluble blood protein that becomes insoluble and forms fibrin strands during last steps of clotting. Bilirubin is the breakdown product of hemoglobin. Thus, the correct answer is C.

An anticoagulant is

  1. Heparin

  2. Hirudin

  3. EDTA

  4. All of the above


Correct Option: D
Explanation:

Heparin is a natural anticoagulant in the body. Hirudin is an anticoagulant produced by leech while sucking the blood of the host. EDTA acts as an anticoagulant by removing calcium ions from the blood and thus chelates with them.

Thus, the correct answer is option D. 

During blood clotting, fibrin is produced by

  1. Thrombokinase

  2. Prothrombin

  3. Liver

  4. Proteolysis


Correct Option: B
Explanation:
During the process of blood clotting, platelets release thromboplastin which converts prothrombin into thrombin. This thrombin in the presence of calcium ions is responsible for conversion of fibrinogen into insoluble fibrin, thus forming a clot
So, the correct answer is 'Prothrombin'

Which of the following is an anticoagulant and checks blood coagulation in blood vessels?

  1. Prothrombin

  2. Globulin

  3. Thromoboplastin

  4. Heparin


Correct Option: D
Explanation:

Heparin is a natural anticoagulant produced in the liver and helps in checking the clotting of blood inside blood vessels. 

During blood clotting, which of the following is used?

  1. Co

  2. $Ca^{++}$

  3. $Na^+$

  4. $Cl^-$


Correct Option: B
Explanation:

Blood clotting (coagulation) is the process by which blood vessels repair ruptures after injury. Calcium works together with vitamin K and a protein, called as fibrinogen in the clotting cascade, which forms fibrin. The fibrin hardens very quickly to form a scab over the wound. 

Hence, correct answer is option B.

Prothrombin is found in

  1. Intestine and helps in cellulose digestion

  2. Liver and helps in production of bile

  3. Blood and gives red colour to blood

  4. Blood and helps in blood clotting


Correct Option: D
Explanation:

Prothrombin is a plasma protein which is converted into thrombin in the presence of thromboplastin released by platelets at the site of injury. The thrombin then converts protein fibrinogen into insoluble fibrin and thus aids in blood clotting. 

Which of the following does not play a role in blood coagulation?

  1. Vitamin K

  2. Vitamin D

  3. Calcium ions

  4. Fibrinogen


Correct Option: B
Explanation:

Coagulation (also known as clotting) is the process by which blood changes from a liquid to a gel, forming a clotThe activation of some of the enzymes in the coagulation cascade is dependent on vitamin K. In the presence of other plasma proteins (clotting factors) and calcium ions, this leads to the activation of a protein called as factor X. 

Fibrinogen or factor I is a blood plasma protein that is made in the liver. It is one of 13 coagulation factors responsible for normal blood clotting. 
Vitamin D is required for the formation of strong bones and does not play any role in blood clotting. 
Hence, the correct answer is option B.