![](/olcweb/styles/shared/spacer.gif) |
1 | ![](/olcweb/styles/shared/spacer.gif) | ![](/olcweb/styles/shared/spacer.gif) In this lab, contractions of the heart produced upward deflections of the line tracing. Was the deflection produced by the contracting ventricle: |
| ![](/olcweb/styles/shared/spacer.gif) | A)![](/olcweb/styles/shared/spacer.gif) | smaller than that produced by the contracting atria? |
| ![](/olcweb/styles/shared/spacer.gif) | B)![](/olcweb/styles/shared/spacer.gif) | about the same size as that produced by the contracting atria? |
| ![](/olcweb/styles/shared/spacer.gif) | C)![](/olcweb/styles/shared/spacer.gif) | larger than that produced by the contracting atria? |
|
|
![](/olcweb/styles/shared/spacer.gif) |
2 | ![](/olcweb/styles/shared/spacer.gif) | ![](/olcweb/styles/shared/spacer.gif) Look at your data. In the first part of the lab, when no thread was tied around the heart, the time interval between atrial contractions was: |
| ![](/olcweb/styles/shared/spacer.gif) | A)![](/olcweb/styles/shared/spacer.gif) | much shorter than the time interval between ventricle contractions. |
| ![](/olcweb/styles/shared/spacer.gif) | B)![](/olcweb/styles/shared/spacer.gif) | about the same as the time interval between ventricle contractions. |
| ![](/olcweb/styles/shared/spacer.gif) | C)![](/olcweb/styles/shared/spacer.gif) | much longer than the time interval between ventricle contractions. |
|
|
![](/olcweb/styles/shared/spacer.gif) |
3 | ![](/olcweb/styles/shared/spacer.gif) | ![](/olcweb/styles/shared/spacer.gif) When thread was tied across the two atria, the line tracing: |
| ![](/olcweb/styles/shared/spacer.gif) | A)![](/olcweb/styles/shared/spacer.gif) | did not change when compared with the tracing from the normal heart. |
| ![](/olcweb/styles/shared/spacer.gif) | B)![](/olcweb/styles/shared/spacer.gif) | showed that just the ventricle was contracting. |
| ![](/olcweb/styles/shared/spacer.gif) | C)![](/olcweb/styles/shared/spacer.gif) | showed that just the atria were contracting. |
| ![](/olcweb/styles/shared/spacer.gif) | D)![](/olcweb/styles/shared/spacer.gif) | showed that just the ventricle and the atria were contracting asynchronously. |
|
|
![](/olcweb/styles/shared/spacer.gif) |
4 | ![](/olcweb/styles/shared/spacer.gif) | ![](/olcweb/styles/shared/spacer.gif) When thread was tied across the two atria and produced only atrial contractions, was the time interval between the atrial contractions: |
| ![](/olcweb/styles/shared/spacer.gif) | A)![](/olcweb/styles/shared/spacer.gif) | significantly shorter than the time interval between atrial contractions recorded from the normal heart. |
| ![](/olcweb/styles/shared/spacer.gif) | B)![](/olcweb/styles/shared/spacer.gif) | about the same as the time interval between atrial contractions recorded from the normal heart. |
| ![](/olcweb/styles/shared/spacer.gif) | C)![](/olcweb/styles/shared/spacer.gif) | significantly longer than the time interval between atrial contractions recorded from the normal heart. |
|
|
![](/olcweb/styles/shared/spacer.gif) |
5 | ![](/olcweb/styles/shared/spacer.gif) | ![](/olcweb/styles/shared/spacer.gif) When thread was tied across the sulcus, the line tracing: |
| ![](/olcweb/styles/shared/spacer.gif) | A)![](/olcweb/styles/shared/spacer.gif) | did not change when compared with the tracing from the normal heart. |
| ![](/olcweb/styles/shared/spacer.gif) | B)![](/olcweb/styles/shared/spacer.gif) | showed that just the ventricle was contracting. |
| ![](/olcweb/styles/shared/spacer.gif) | C)![](/olcweb/styles/shared/spacer.gif) | showed that just the atria were contracting. |
| ![](/olcweb/styles/shared/spacer.gif) | D)![](/olcweb/styles/shared/spacer.gif) | showed that just the ventricle and the atria were contracting asynchronously. |
|
|
![](/olcweb/styles/shared/spacer.gif) |
6 | ![](/olcweb/styles/shared/spacer.gif) | ![](/olcweb/styles/shared/spacer.gif) When thread was tied across the sulcus and the atria and ventricle contracted asynchronously, was the time interval between the atrial contractions: |
| ![](/olcweb/styles/shared/spacer.gif) | A)![](/olcweb/styles/shared/spacer.gif) | significantly shorter than the time interval between atrial contractions recorded from the normal heart. |
| ![](/olcweb/styles/shared/spacer.gif) | B)![](/olcweb/styles/shared/spacer.gif) | about the same as the time interval between atrial contractions recorded from the normal heart. |
| ![](/olcweb/styles/shared/spacer.gif) | C)![](/olcweb/styles/shared/spacer.gif) | significantly longer than the time interval between atrial contractions recorded from the normal heart. |
|
|
![](/olcweb/styles/shared/spacer.gif) |
7 | ![](/olcweb/styles/shared/spacer.gif) | ![](/olcweb/styles/shared/spacer.gif) If the time between atrial contractions was independent of experimental manipulation, where is the pacemaker for atrial contractions? |
| ![](/olcweb/styles/shared/spacer.gif) | A)![](/olcweb/styles/shared/spacer.gif) | The sinoatrial (SA) node. |
| ![](/olcweb/styles/shared/spacer.gif) | B)![](/olcweb/styles/shared/spacer.gif) | The atrioventricular (AV) node. |
| ![](/olcweb/styles/shared/spacer.gif) | C)![](/olcweb/styles/shared/spacer.gif) | The atrioventricular (AV) bundle (or bundle of His). |
| ![](/olcweb/styles/shared/spacer.gif) | D)![](/olcweb/styles/shared/spacer.gif) | The Purkinje fibers. |
|
|
![](/olcweb/styles/shared/spacer.gif) |
8 | ![](/olcweb/styles/shared/spacer.gif) | ![](/olcweb/styles/shared/spacer.gif) When thread was tied across the sulcus and the atria and ventricle contracted asynchronously, was the time interval between ventricle contractions: |
| ![](/olcweb/styles/shared/spacer.gif) | A)![](/olcweb/styles/shared/spacer.gif) | significantly shorter than the time interval between ventricle contractions recorded from the normal heart. |
| ![](/olcweb/styles/shared/spacer.gif) | B)![](/olcweb/styles/shared/spacer.gif) | about the same as the time interval between ventricle contractions recorded from the normal heart. |
| ![](/olcweb/styles/shared/spacer.gif) | C)![](/olcweb/styles/shared/spacer.gif) | significantly longer than the time interval between ventricle contractions recorded from the normal heart. |
|
|
![](/olcweb/styles/shared/spacer.gif) |
9 | ![](/olcweb/styles/shared/spacer.gif) | ![](/olcweb/styles/shared/spacer.gif) When thread was tied across the sulcus and the atria and ventricle contracted asynchronously: |
| ![](/olcweb/styles/shared/spacer.gif) | A)![](/olcweb/styles/shared/spacer.gif) | the atria and ventricle were excited by the pacemaker in the SA node. |
| ![](/olcweb/styles/shared/spacer.gif) | B)![](/olcweb/styles/shared/spacer.gif) | only the occasional action potential made its way through the AV node to excite the ventricle. |
| ![](/olcweb/styles/shared/spacer.gif) | C)![](/olcweb/styles/shared/spacer.gif) | the pacemaker for the (less frequent) ventricle contractions was not in the SA node. |
|
|
![](/olcweb/styles/shared/spacer.gif) |
10 | ![](/olcweb/styles/shared/spacer.gif) | ![](/olcweb/styles/shared/spacer.gif) When thread was tied across the sulcus and the atria and ventricle contracted asynchronously, the pacemaker for the (slower) ventricle contractions was: |
| ![](/olcweb/styles/shared/spacer.gif) | A)![](/olcweb/styles/shared/spacer.gif) | in the sinoatrial (SA) node. |
| ![](/olcweb/styles/shared/spacer.gif) | B)![](/olcweb/styles/shared/spacer.gif) | in the AV node, the AV bundle, or the Purkinje fibers. |
| ![](/olcweb/styles/shared/spacer.gif) | C)![](/olcweb/styles/shared/spacer.gif) | created by blood as it stretched the wall of the ventricle. |
|
|