Question 1

Q1: Name the components of the formed elements in the blood and mention one major function of each of them.

Accepted Answer

The components of the formed elements in the blood are Erythrocytes (RBCs), Leucocytes (WBCs), and Platelets. They constitute about 45 per cent of the blood. Their major functions are as follows: 1.  Erythrocytes (Red Blood Cells or RBCs): These are the most abundant cells in the blood. Their primar...

Question 2

Q10: Sino-atrial node is called the pacemaker of our heart. Why?

Accepted Answer

The sino-atrial node (SAN), a patch of specialized nodal tissue located in the right upper corner of the right atrium, is called the pacemaker of the heart because it initiates the cardiac impulse that determines the heart rate. The SAN has the unique property of autoexcitability and can generate th...

Question 3

Q11: What is the significance of atrio-ventricular node and atrio-ventricular bundle in the functioning of heart?

Accepted Answer

The atrio-ventricular node (AVN) and the atrio-ventricular bundle (AV bundle or Bundle of His) are crucial components of the heart's conduction system and have the following significance: 1.  Conduction of Impulse: They act as the electrical relay station between the atria and the ventricles. The ac...

Question 4

Q12: Define a cardiac cycle and the cardiac output.

Accepted Answer

Cardiac Cycle: The cardiac cycle is the sequential event in the heart which is cyclically repeated from the beginning of one heartbeat to the beginning of the next. It consists of the systole (contraction) and diastole (relaxation) of both the atria and the ventricles. In a normal person with a hear...

Question 5

Q13: Explain heart sounds.

Accepted Answer

During each cardiac cycle, two prominent sounds are produced which can be heard using a stethoscope. These sounds are of clinical diagnostic significance. 1.  First Heart Sound (lub): This is the first sound, 'lub'. It is produced by the closure of the atrioventricular (AV) valves, namely the tricus...

Question 6

Q14: Draw a standard ECG and explain the different segments in it.

Accepted Answer

A standard electrocardiogram (ECG) is a graphical representation of the electrical activity of the heart during a cardiac cycle. As I cannot draw, I will describe the components with reference to Figure 15.3 in the textbook. A standard ECG has the following waves: 1. P-wave:    This is the first sma...

Question 7

Q2: What is the importance of plasma proteins?

Accepted Answer

Plasma proteins are crucial for several physiological functions in the body. The major proteins found in plasma are fibrinogen, globulins, and albumins. Their importance is as follows: 1.  Fibrinogen: This protein is essential for the clotting or coagulation of blood. It is converted into fibrin thr...

Question 8

Q3: Match Column I with Column II : Column I (a) Eosinophils (b) RBC (c) AB Group (d) Platelets (e) Systole Column II (i) Coagulation (ii) Universal Recip...

Accepted Answer

The correct matches are as follows:    (a) Eosinophils matches with (iii) Resist Infections. Eosinophils are a type of white blood cell that resists infections and is also associated with allergic reactions.    (b) RBC matches with (v) Gas transport. Red blood cells contain haemoglobin, which plays...

Question 9

Q4: Why do we consider blood as a connective tissue?

Accepted Answer

Blood is considered a special connective tissue for two main reasons that align with the definition of connective tissues: 1.  Presence of a Matrix: Like other connective tissues, blood consists of cells and cell fragments (the formed elements) suspended in an extensive extracellular matrix. In the...

Question 10

Q5: What is the difference between lymph and blood?

Accepted Answer

Question 11

Q6: What is meant by double circulation? What is its significance?

Accepted Answer

Double Circulation is a system of circulation in which blood flows through the heart twice for each complete circuit of the body. It consists of two separate pathways: 1.  Pulmonary Circulation: This pathway involves the circulation of blood between the heart and the lungs. The right ventricle pumps...

Question 12

Q7: Write the differences between : (a) Blood and Lymph (b) Open and Closed system of circulation (c) Systole and Diastole (d) P -wave and T -wave

Accepted Answer

Question 13

Q8: Describe the evolutionary change in the pattern of heart among the vertebrates.

Accepted Answer

The pattern of the heart among vertebrates shows a clear evolutionary progression from a simple two-chambered heart to a more complex and efficient four-chambered heart. 1.  Fishes: They possess the simplest heart, which is 2-chambered, consisting of one atrium and one ventricle. The heart pumps out...

Question 14

Q9: Why do we call our heart myogenic?

Accepted Answer

The human heart is called myogenic because its normal rhythmic contractile activity is initiated and regulated intrinsically by a specialized muscle tissue within the heart itself, known as the nodal tissue. This tissue, particularly the sino-atrial node (SAN), has the ability to generate electrical...

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