Final answer:
The lack of pressure pulse is found in the capillaries, venules, and veins due to the significantly reduced blood pressure after blood has passed through arterioles. Veins help carry blood back to the heart at low pressure, have thin walls, and contain valves to prevent backflow.
Step-by-step explanation:
The vessel where there is a lack of pressure pulse is in the capillaries, venules, and veins. This corresponds to option c in your query, capillaries, venules, and veins. Pressure pulses are most evident in the large arteries, as blood is pumped directly from the heart, creating a surge with each heartbeat. However, by the time blood has traveled to the capillaries, it has passed through arterioles, where resistance to blood flow reduces the pressure significantly. As the blood progresses through the capillaries and enters the venules and eventually the veins, the pressure continues to drop and the pulse is no longer palpable. Veins are designed to transport blood back to the heart at a low pressure, and they have thin walls, large lumens, and valves that assist in ensuring the unidirectional flow of blood.