MCQ
Given below is the ECG of a normal human. Which one of its components is correctly interpreted below?
Image
  • A
    Peak P and Peak R together - systolic and diastolic blood pressures
  • B
    Peak P - Initiation of left atrial contraction only
  • C
    Peak T - Initiation of total cardiac contraction
  • D
    Complex QRS - One complete pulse

Answer

D. Complex QRS - One complete pulse
Explanation:
The QRS complex shows one complete pulse. It represents the depolarisation of the ventricles, which initiates the ventricular contraction. The contraction starts shortly after Q and marks the beginning of the systole.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Evolution is regarded as
A woman with two genes for haemophillia and one gene for colourblindness on one of the $X$ chromosomes marries a normal man. How will the progeny be
$A$ -Spermatids formed from secondary spermatocytes.

$R$ -The spermatids are transformed into spermatozoa by the process called spermiogenesis.

$GIFT$ is
Right auricle of mammalian heart receives blood from
The functioning of the kidneys is efficiently monitored and regulated by hormonal feedback mechanisms involving the hypothalamus, JGA and to a certain extent, the heart. From given statements about JGA control, select correct option from below:
(i) It is controlled by Renin-Angiotensin mechanism.
(ii) A fall in glomerular blood flow/glomerular blood pressure/GFR can activate the JG cells to release renin.
(iii) Renin converts angiotensinogen to angiotensin I.
(iv) Angiotensin II. being a powerful vasoconstrictor, increases the glomerular blood pressure and thereby GFR.
(v) Angiotensin I activates the adrenal cortex to release aldosterone.
(vi) Aldosterone causes reabsorption of Na+ and water from the distal parts of the tubule. This also leads to an increase in blood pressure and GFR.
The chromosome maps are not accurate maps because
Arrange the following steps of muscle contraction in the sequence of events occurring first

$I.$ Receptor sites on sarcolemma

$II.$ Nerve impulse

$III.$ Release of $\mathrm{Ca} \hat{\imath}$

$IV.$ Acetylcholine release

$V.$ Shortening of sarcomere

$VI.$ Synaptic cleft

$VII.$ Spread of impulse over sarcolemma on T-tubule

The correct option is

Which is correct for level of organization?
Petromyzon belongs to