Circulatory System Flashcards
1
Q
Vasoconstriction
A
the narrowing of vessel diameter. Less blood is delivered to the tissues.
2
Q
Vasodilation
A
the widening of vessel diameter. More blood is delivered to the tissues.
3
Q
How does blood in veins move back to the heart?
A
Skeletal muscle action “squeezes” the veins and helps the movement of blood in the veins back toward the heart.
4
Q
What prevents the back flow of blood in veins?
A
One-way valves
5
Q
Electrical impulses normally originate within a specialized tissue called the _____________
A
Sinoatrial node (SA node)
6
Q
What is the “pacemaker” of the heart?
A
The sinoatrial node
7
Q
What is the Bundle of His?
A
A band of conducting fibers that divides into right and left bundle branches which travel to the right and left ventricles.
