Answer to Question 1
D
Infants are much more sensitive to central nervous system drugs than older children and adults, as the blood-brain barrier is not fully developed at birth.
From a therapeutic perspective, the blood-brain barrier is a mixed blessing. On the positive side, it protects the brain from injury by potentially toxic substances. However, it also makes it difficult to treat diseases affecting the brain.
The blood-brain barrier is not fully developed at birth; no further teaching is required.
Answer to Question 2
A
Postural hypotension is caused by the pooling of blood in the veins, which reduces venous return, resulting in venous dilation and tachycardia as compensatory mechanisms.
An increase in cardiac output would not occur.
The heart rate would actually increase, not decrease.
Pulmonary edema would not occur.