00:01
Okay, this question here says during a study of exercise physiology a healthy 30 year old woman runs a treadmill for 20 minutes at a rate of 7 miles per hour.
00:11
At the end of the study her cardiac output has increased from 5 liters per minute to 15.
00:17
The cerebral perfusion pressure has remained relatively constant.
00:20
Which are the following mechanisms best explains this finding? you have decreased endocardial pressure, increased cerebrospinal fluid absorption, increased venous drainage, myogenic arterial constriction or grief -lexed vertecardia.
00:36
In this case the cerebral perfusion pressure has remained constant.
00:44
You just have increased the cardiac output.
00:49
So when we exercise there are many physiologic mechanisms that occur when we exercise.
00:57
One of them is that there is going to be, for example, tachycardia in order to supply more blood or to deliver more blood and oxygen to the muscles.
01:06
Also there can be myogenic arterial constriction because in this case if this is your muscle you're going to have here your arterioles.
01:13
But when your muscle contracts what is going to happen? this muscle is going to compress these arterioles.
01:20
So your muscle is going to be practically isolated because these vessels here are constricted...