Final answer:
The order of increasing blood pressure in the vessels is capillaries, arterioles, arteries, and finally, the aorta. The arterioles play a crucial role in this gradient by regulating resistance, which affects blood pressure significantly.
Step-by-step explanation:
When listing the vessels in order of increasing blood pressure, we start with the capillaries, which have the lowest pressure. This is followed by arterioles, then arteries, and finally, the aorta, which has the highest blood pressure. Blood pressure is the highest in the aorta, as it is the large vessel that receives blood directly from the heart and must accommodate the initial force of the heart's contractions. As blood travels through the system, it encounters increasing resistance, particularly in the arterioles, which are referred to as resistance vessels due to their role in regulating blood flow through vasoconstriction and vasodilation. The overall blood pressure decreases as it moves from the larger arteries to the arterioles and through the vast capillary networks before returning to the heart through veins.
The critical role of arterioles in this pressure gradient is their ability to regulate resistance, thus influencing blood pressure throughout the body. Cocaine use, which causes vasoconstriction, would likely increase blood pressure due to increased resistance.