Cardiac Cycle

PrepBank · পাতা ১ / ১ · ১–৫ / ৫

১.

At a normal heart rate the duration(second) of atrial systole is

ক
0.1
খ
0.3
গ
0.5
ঘ
0.7

ব্যাখ্যা

Explanation:
At a normal heart rate the duration of systole and diastole are:
Atrial systole: 0.1 second
Atrial diastole: 0.7 second
Ventricular systole: 0.3 second
Ventricular diastole: 0.5 second

২.

Which initiates cardiac cycle

ক
ক) Atrial systole
খ
খ) Atrial diastole
গ
গ) Ventricular systole
ঘ
ঘ) Ventricular diastole

ব্যাখ্যা

Explanation:
Atrial systole initiates cardiac cycle because the sinus node (pacemaker) of the heart is located in the right atrium.

৩.

Cardiac cycle is the term used to describe the sequence of events that occur as the heart works to pump blood through the body. The opening of the atrioventricular(AV) valves occurs at about the same time in the cardiac cycle as-

ক
ক) Beginning of diastole
খ
খ) Beginning of systole
গ
গ) End of isovolumic contraction
ঘ
ঘ) First heart sound

ব্যাখ্যা

The second is a shorter, high-pitched “dub” (second sound), caused by vibrations associated with closure of the aortic and pulmonary valves just after the end of ventricular systole and beginning of diastole.

৪.

At a normal heart rate, the duration(second) of ventricular systole is

ক
ক) 0.1
খ
খ) 0.3
গ
গ) 0.5
ঘ
ঘ) 0.7

ব্যাখ্যা

Explanation:
At a normal heart rate the duration of systole and diastole are:
Atrial systole: 0.1 second
Atrial diastole: 0.7 second
Ventricular systole: 0.3 second
Ventricular diastole: 0.5 second

৫.

Plateau phase of action potential

ক
Is due to K efflux
খ
Oprning of transient calcium channel.
গ
Causes prolongation of refractory period
ঘ
Coincides with ventricular diastole

ব্যাখ্যা

Mainly due to calcium influx

▶ due to slow long lasting ca²+- Na+

▶ coincides with ventricular systole

▶ Results in prolonged refractory period