Breathing and Exchange of Gases

Human beings possess which type of circulatory system?

1. Open circulatory system
2. Closed circulatory system with single circulation
3. Closed circulatory system with double circulation
4. Mixed circulatory system

Which clotting factor is converted into fibrin during blood coagulation?

1. Albumin
2. Globulin
3. Fibrinogen
4. Haemoglobin

The normal resting heart rate of a healthy adult is approximately:

1. 30-40 beats per minute
2. 50-55 beats per minute
3. 70-75 beats per minute
4. 120-130 beats per minute

Which vessel has the thickest muscular wall?

1. Vein
2. Capillary
3. Artery
4. Venule

The pulmonary circulation is the movement of blood between:

1. Heart and kidneys
2. Heart and lungs
3. Heart and liver
4. Heart and brain

Which component of blood is directly involved in body defence against pathogens?

1. RBCs
2. Platelets
3. Plasma proteins only
4. White Blood Cells (WBCs)

The lub sound ("LUB") of the heartbeat is produced due to:

1. Closure of semilunar valves
2. Closure of atrioventricular valves
3. Opening of semilunar valves
4. Opening of atrioventricular valves

The pacemaker of the human heart is the:

1. Atrioventricular (AV) node
2. Bundle of His
3. Purkinje fibres
4. Sinoatrial (SA) node

The bicuspid (mitral) valve is located between:

1. Right atrium and right ventricle
2. Left atrium and left ventricle
3. Left ventricle and aorta
4. Right ventricle and pulmonary artery

Which blood cells play the most important role in blood clotting?

1. Erythrocytes
2. Platelets
3. Neutrophils
4. Lymphocytes

Which blood group is known as the universal recipient?

1. A
2. B
3. AB
4. O

Which blood group is known as the universal donor?

1. A
2. B
3. AB
4. O

Which plasma protein is mainly responsible for maintaining the osmotic pressure of blood?

1. Globulin
2. Albumin
3. Fibrinogen
4. Haemoglobin

Which component of blood is primarily responsible for transporting oxygen?

1. Plasma
2. Platelets
3. Red Blood Cells (RBCs)
4. White Blood Cells (WBCs)