Biology · General Awareness

Human Circulatory System

818 Questions

The human circulatory system explores the network of blood vessels, heart valves, and structural pathways. Test items often target blood flow sequences and specific vascular functions. Mastering these details is vital for biology preparation.

Heart valves and chambersBlood vessels and venulesArteries of the bodyBlood supply to organsCentral nervous system supply

Human Circulatory System Questions

Multiple choice biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

Which of the following statements are correct?


(i) $Ca^{+2}$ is necessary for blood coagulation.
(ii)Coagulation in blood vessel is prevented during normal condition by heparin.
(iii)Clotting of blood involves changes of fibrinogen to fibrin by thrombin.
(iv)Blood clotting involves cascading process involving a number of factors present always in the active form.

  1. (i), (iii) and (iv)

  2. (ii) and (iv)

  3. (i) and (iii)

  4. (iii) and (iv)
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ca\${+2}\$ is necessary for blood coagulation -

1. Conversion of prothrombin to thrombin, in presence of prothrombin activator and Ca\${+2)\$
2. Conversion of fibrinogen monomers in to fibrin fibres  
III fibrinogen is thin soluable protein that is converted to insoluable protein fibres by thrombin
So, the correct answer is 'i and iii'

Multiple choice biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

Identify $A,B$ and $C$ in the given blood clotting process.
Damage platelets release $A$;$A$ converts $D$ into $B$ in presence of Calcium ions. $B$ converts $C$ into Fibrin thread.

  1. A-Thromboplastin,B-Prothrombin,C-Fibrinogen

  2. A-Thrombin,B-Fibrinogen,C-Thrombo-kinase

  3. A-Thromboplastin,B-Thrombin,C-Fibrinogen

  4. A-Prothrombin,B-Thrombin,C-Fibrinogen
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In the clotting cascade, damaged platelets release thromboplastin (A), which converts prothrombin (D) into thrombin (B) in the presence of calcium. Thrombin then converts fibrinogen (C) into fibrin threads.

Multiple choice biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

Blood clot formed in vessels blocking the flow of the blood is called as the

  1. Bolus

  2. Pus

  3. Ulcer

  4. Thrombus
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
A thrombus is a blood clot that forms in a vessel and remains there. Clot leads to the coagulation of particles forming a thickened mass. It is traveled from the site of its production to another location in the body. It can block the flow of blood in that location depriving tissues of normal blood flow and oxygen. This can result in damage, destruction (infarction), or even death of the tissues (necrosis) in that area. 
Multiple choice biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

A drop of each of the following, is placed separately on four slides. Which one of them will not coagulate?

  1. Blood serum

  2. Sample from thoracic duct of lymphatic system

  3. Whole blood from pulmonary vein

  4. Blood plasma
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Blood serum is the component of blood that has neither a blood cell nor a clotting factor. Serum includes all proteins not used in blood clotting (coagulation) and all the electrolytes, antibodies, antigens, hormones, and any exogenous substances (e.g., drugs and microorganisms). Hence, serum does not clot. Thus, the correct answer is option A.

Multiple choice biology soldiers of defense blood clotting and healing of wounds coagulation of blood 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
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

Multiple choice biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

Coagulation of blood in vessels is prevented during normal circulation by

  1. Heparin

  2. Prothrombin

  3. Plasminogen

  4. Thromplastin
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Heparin is a natural anticoagulant of the body produced in the liver. It is normally found circulating through the bloodstream. It prevents the blood clotting in veins and arteries during normal circulation.

Thus, the correct answer is option A.

Multiple choice biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

Blood clot inside a blood vessel is known as  

  1. Thrombosis

  2. Agglutinin

  3. Clot

  4. Thrombus
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A blood clot that forms inside one of your veins or arteries is called a thrombus. A thrombus may also form in your heart. A thrombus that breaks loose and travels from one location in the body to another is called an embolus.

So, the correct option is 'Thrombus'.

Multiple choice biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

What happens when a clot occurs in an undamaged blood vessel?

  1. The person would bleed to death.

  2. A scab will form on the skin surface.

  3. Platelets stick to the edges of the cut and to one another, forming a plug.

  4. The flow of blood to tissues beyond the clot may be cut off.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

When a clot occurs in an undamaged blood vessel, It stops the flow of blood to the rest of the tissue beyond the clot as, the blood can't flow through the clot. It causes paralysis in most of the cases. 

Therefore, the correct answer is option D.

Multiple choice biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

Blood does not clot inside the blood vessels due to the presence of

  1. Heparin

  2. Fibrinogen

  3. Vitamin K

  4. Thrombin
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Liver produces an anticoagulant, hetero-polysaccharide called heparin which prevent clotting inside the blood vessels. Heparin is a highly sulfated glycosaminoglycan and is also used to form an inner anticoagulant surface on experimental and medical devices.
Fibrinogen is a glycoprotein that helps in the formation of blood clots.
Thrombin is a blood coagulation factor.
Thus, the correct answer is option A. 
Multiple choice biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

A drop of each of the following, is placed separately on four slides. Which of them will not coagulate?

  1. Blood plasma

  2. Blood serum

  3. Sample from the thoracic duct of lymphatic system

  4. Whole blood from pulmonary vein
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Coagulation is the process by which the blood changes from a liquid to a gel-like form. Blood plasma will coagulate, as, it has clotting factors in it and fibrinogen protein.
Serum will not coagulate, as, it do not have any clotting factors and fibrinogen.
Lymph is more like blood plasma, so, contains clotting factors and will coagulate.
Whole blood obviously coagulate for containing the same above factors.
Thus, the correct answer is option (B).

Multiple choice biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

Which of the following protein is responsible for spontaneous blood clotting?

  1. Factor XII

  2. Factor XI

  3. Factor IX

  4. Factor VIII
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Factor VIII is an important blood clotting protein, which is also known as anti-haemophilic factor (AHF), encoded by the F$ _{8}$ gene.
Factor VIII circulates in the bloodstream in an inactive form, bound to another molecule, called Von Willebrand factor, until an injury that damages the blood vessels occurs. When injury occurs, the factor VIII is activated and separates from Von Willebrand factor. The active protein interacts with another coagulation factor, called factor IX. This interaction leads to a chain of additional reactions, that form a blood clot.

Multiple choice biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

Protein required for coagulation of blood is

  1. Haemoglobin

  2. Globulin

  3. Fibrinogen

  4. Albumin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The mechanism of blood clotting involves the presence of calcium and other clotting factors, Factor X activates an enzyme called prothrombin activator. The enzyme prothrombin activator then converts plasma protein prothrombin into thrombin. Thrombin is the enzyme which in turn converts fibrinogen into fibrin. Polymerized fibrin together with platelets forms a clot at the wound site. Hence Protein required for coagulation of blood is Fibrinogen. It is a blood plasma protein made in the liver and present in circulating blood.
So, the correct answer is 'Fibrinogen'
Multiple choice biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

Blood protein which initiates blood coagulation is

  1. Prothrombin

  2. Thrombin

  3. Fibrinogen

  4. Fibrin
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Prothrombin is a plasma protein essential for blood clotting. Whenever there is an injury, prothrombin activator complex is formed. Prothrombin is converted into thrombin by activators. Thrombin acts as an enzyme and converts plasma protein fibrinogen into fibrin threads which form a clot at the site of injury and bleeding is stopped.
So, the correct answer is 'Prothrombin'.