Body Fluids and Circulation

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ËLËÇTRØÇÅRDÏØGRÅPH (ËÇG)

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It is an instrument used to obtain electrocardiogram, graphical

representation of the electrical activity of the heart during a cardiac

cycle.

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To get an ECG, a patient is

connected to the machine

with 3 electrical leads (one to

each wrist and to left ankle)

that monitor heart activity. For

a

detailed

evaluation

of

heart’s function, multiple leads

are attached to the chest

region.

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Each peak in the ECG is

identified with a letter from P

to T that corresponds to a specific electrical activity of the heart.

An ECG consists of the following waves:

P-wave

Represents the

excitation

(depolarisation) of

atria which causes

atrial systole.

QRS- Complex

Represents

depolarisation of

ventricles

(ventricular

systole).

(NEET 2020)

T- waves

Represents the

repolarisation of

ventricles.

1

2

3

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Deviation in the ECG indicates the abnormality or disease. So, ECG has

great clinical significance.

DØÜBLË ÇÏRÇÜLÅTÏØÑ

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It is the circulation in which blood flows through the heart twice for

completing its circuit.

PÜLMØÑÅRÝ ÇÏRÇÜLÅTÏØÑ

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Circulation between lungs and heart. Deoxygenated blood from right

ventricle to pulmonary artery - to lungs and oxygenated blood from

pulmonary veins - left atrium.