Biology

Body Fluids and Circulation

Question:

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

Answer:

ECG is graphic record of the electric current produced by the excitation of the cardiac muscles. The instrument used to record the changes is an electrocardiograph. A normal electrogram (ECG) is composed of a P wave, a QRS wave (complex) and a T wave. The P Wave is a small upward wave that represents electrical excitation or the atrial depolarisation which leads to contraction of both the atria (atrial contraction). It is caused by the activation of SA node. The impulses of contraction start from the SAnode and spread throughout the artia.
The QRS Wave (complex) represents ventricular depolarisation (ventricular contraction). It is caused by the impulses of the contraction from AV node through the bundle of His and Purkinje fibres and the contraction of the ventricular muscles. Thus this wave is due to the spread of electrical impulse through the ventricles.
The T Wave represents ventricular repolarisation (ventricular relaxation). The potential generated by the recovery of the ventricle from the depolarisation state is called the repolarisation wave. The end of the T-wave marks the end of systole.
ECG gives accurate information about the heart. Therefore, ECG is of great diagnostic value in cardiac diseases.
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Body Fluids and Circulation

Q 1.

Explain heart sounds.

Q 2.

Explain the consequences of a situation in which blood does not coagulate.

Q 3.

Why do we call our heart myogenic?

Q 4.

Given below are the abnormal conditions related to blood circulation. Name the disorders.
(a) Acute chest pain due to failure of 02 supply to heart muscles
(b) Increased systolic pressure

Q 5.

State the functions of the following in blood
(a) Fibrinogen
(b) Globulin
(c) Neutrophils
(d) Lymphocytes

Q 6.

Complete the missing word in the statement given below:
(a) Plasma without_______factors is called  serum.
(b) _______and monocytes are  phagocytic cells.
(c) Eosinophils are associated with  reactions.
(d)_______ions play a significant role in  clotting.
(e) One can determine the heart beat rate by  counting the number of_______in an ECG.

Q 7.

Match Column I with Column II.
Column I                          Column II
(a) Eosinophils               (i) Coagulation
(b) RBC                            (ii) Universal recipient
(c) AB Group                  (iii) Resist infections
(d) Platelets                    (iv) Contraction of heart
(e) Systol                         (v) Gas transport

Q 8.

Define a cardiac cycle and the cardiac output.

Q 9.

Why do we call our heart myogenic?

Q 10.

Why do we consider blood as a connective tissue?

Q 11.

Answer the following:
(a) Name the major formed.  Which part of heart is responsible for initiating and maintaining its rhythmic activity?  What is specific in the heart of crocodiles among reptilians?

Q 12.

Explain the advantage of the complete partition of ventricle among birds and mammals and hence leading to double circulation.

Q 13.

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

Q 14.

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

Q 15.

Briefly describe the following:
(a) Anaemia
(b) Angina pectoris
(c) Atherosclerosis
(d) Hypertension
(e) Heart failure
(f) Erythroblastosis foetalis

Q 16.

Name the blood component which is viscous and straw coloured fluid.

Q 17.

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

Q 18.

Which coronary artery disease is caused due to narrowing of the lumen of arteries?

Q 19.

Describe the events in cardiac cycle. Explain “double circulation”.

Q 20.

What is the significance of hepatic portal system in the circulatory system?

Q 21.

How will you interpret an electrocardiogram (ECG) in which time taken in QRS complex is higher?

Q 22.

Explain the functional significance of lymphatic system.

Q 23.

Write short note on the following:
(a) Hypertension
(b) Coronary Artery Disease

Q 24.

Name the vascular connection that exists between the digestive tract and liver.

Q 25.

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

Q 26.

What is the importance of plasma proteins?

Q 27.

Explain Rh-incompatibility in humans.

Q 28.

What physiological circumstances lead to erythroblastosis foetalis?

Q 29.

Explain different types of blood groups and donor compatibility by making a table.

Q 30.

Define the following terms and give their location.
(a) Purkinje fibre
(b) Bundle of His

Q 31.

In the diagrammatic presentation of heart given below, mark and label, SAN, AVN, bundle of His and Purkinje fibres.
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Q 32.

What is the significance of time gap in the  passage of action potential from sino-atrial node to the ventricle?

Q 33.

The walls of ventricles are much thicker than atria. Explain.

Q 34.

What is the difference between lymph and blood?

Q 35.

Given below is the diagrammatic represen-tation of a standard ECG. Label its different peaks.

Q 36.

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

Q 37.

Thrombocytes are essential for coagulation of blood. Comment.

Q 38.

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

Q 39.

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

Q 40.

Differentiate between
(a) Blood and lymph
(b) Basophils and Eosinophils
(c) Tricuspid and bicuspid valve

Q 41.

Write the features that distinguish between the two
(a) Plasma and Serum
(b) Open and closed circulatory system
(c) Sino-atrial node and Atrio-ventricular