Multiple Choice
Blood is moved efficiently through the veins and back to the heart by ____.
A) one-way valves to prevent backflow
B) smooth muscle contraction
C) skeletal muscle contraction
D) a and b only
E) a, b, and c
Correct Answer:

Verified
Correct Answer:
Verified
Q35: _ is known as a cardiac pacemaker.
Q36: One important function of the lymphatic system
Q37: Respond to the following statements in reference
Q38: The _ receives blood from the atrium
Q39: Blood from the superior and inferior vena
Q41: Respond to the following statements in reference
Q42: <img src="https://d2lvgg3v3hfg70.cloudfront.net/TB2278/.jpg" alt=" Figure 36.3
Q43: <img src="https://d2lvgg3v3hfg70.cloudfront.net/TB2278/.jpg" alt=" Figure 36.6
Q44: Blood passes to the lungs from this
Q45: Respond to the following statements in reference