Final answer:
An increase in cardiac output (CO) with unchanged resistance (R) would likely lead to an increased mean arterial pressure (MAP), since MAP is the product of CO and R.
Step-by-step explanation:
If the cardiac output (CO) increased but the resistance (R) in the systemic circulation remained unchanged, the mean arterial pressure (MAP) would likely increase. According to the formula MAP = CO × R, where MAP is determined by the product of CO and R, an increase in CO would result in a proportional increase in MAP if R is constant.
The relationship between CO, R, and MAP is critical in the understanding of cardiovascular physiology, and an increase in CO would suggest more blood being pumped out of the heart into the arteries per minute without a change in the resistance offered by the vessels.