A physician measures the arterial blood pressure of a patient while she is resting and again while she is running on a treadmill. The results of these blood pressure tests are given in the table below. Given this data, was arterial blood pressure during heart contraction higher while the patient was resting or while she was running?

Question

A physician measures the arterial blood pressure of a patient while she is resting and again while she is running on a treadmill.  The results of these blood pressure tests are given in the table below.  Given this data, was arterial blood pressure during heart contraction higher while the patient was resting or while she was running?

Quizplus · Accepted Answer

11ecba2d_101c_f309_a3bf_271d86411689_MD0008_00 Contractions of the heart pump blood through vessels of the circulatory system, facilitating the delivery of oxygen and nutrients to tissues and the removal of waste products (eg, carbon dioxide). Specifically, blood moves away from the heart through the arteries and returns to the heart via the veins. The repetitive heart contractions that facilitate this transport of blood occur in two distinct phases: During the diastole phase, the heart relaxes and fills with blood returning to the heart via the veins. Because blood is not pumped from the heart during diastole, the volume of blood flowing through the arteries is lower, decreasing pressure on the arterial walls. Therefore, arterial blood pressure is lowest during diastole and is measured as the diastolic blood pressure. During the systole phase, the heart contracts and blood is forced from the heart into the arteries. This increased volume of blood flowing through the arteries on contraction of the heart exerts increased pressure (ie, hydrostatic pressure) on the arterial walls. Accordingly, arterial blood pressure is highest during systole and is measured as the systolic blood pressure. In the given scenario, a physician measures the arterial blood pressure of a patient while she is resting and while she is running on a treadmill. Generally, blood pressure measurements (mm Hg) are represented by the higher systolic pressure over the lower diastolic pressure. Therefore, the patient's blood pressure on heart contraction (systolic blood pressure), as shown in the table, was higher while running (155 mm Hg). (Choices A and D) Diastolic blood pressure is measured within the arteries on relaxation of the heart. Although the patient's diastolic blood pressure was higher while resting, this value is not representative of her blood pressure during heart contraction (ie, systolic blood pressure). (Choice B) Systolic blood pressure (measured during heart contraction) is generally greater than diastolic blood pressure and is represented by the upper number in each measurement. Therefore, systolic blood pressure was lower while the patient was resting. Educational objective: Arterial blood pressure is highest when the heart contracts (during systole) and lowest when the heart relaxes (diastole). When measuring blood pressure (mm Hg), the higher systolic blood pressure is recorded over the lower diastolic blood pressure.

A Physician Measures the Arterial Blood Pressure of a Patient