BI 231 - Human Physiology and Anatomy
Blood Pressure Study Guide � local and central control

Compiled by Pat Bowne, Sherry Dollhopf,and Justin LaManna, 2007-11


The blood supply to the tissues is vital. If blood doesn�t perfuse our tissues fast enough, they won�t get enough Oxygen and food, and will smother in their own wastes. But perfusion through the thousands of capillaries is hard to measure. We measure blood pressure in the arteries instead, and that is where your body measures it as well. The goal is to keep blood pressure at a stable level, so that enough blood will go to the tissues to keep them alive � while at the same time, sending extra blood to the tissues that need it most.

Before class, make sure you:

Can write out the path of blood flow.

Can explain the cardiac cycle, and the meaning of systole and diastole.

Can state the meaning of vasoconstriction and vasodilation.

Review the SNS at:
SNS function tutorial

(Pay attention to the receptors on the heart and blood vessels!)

Tutorials and reading assignment: Review the basics of blood pressure at:

Review the Renin-Angiotensin-Aldosterone System at:

Chapter 15, pages 584-592, Ch 13 p. 514

What you should know for the assessment: Blood pressure

Be able to define blood pressure based on its two main components; cardiac output and peripheral resistance

ILLUSTRATE how vasodilation, vasoconstriction, and heart rate work together to maintain blood pressure.

DEFINE peripheral resistance and predict how it will affect blood pressure.

Blood pressure regulation

Explain the homeostatic control of blood pressure using the autonomic systems we discussed in class

Be able to identify and explain all three components (receptor, control center, effecter) involved in blood pressure regulation for each system; sympathetic and parasympathetic

Describe how things like oxygen levels, carbon dioxide levels, and body temperature influence blood flow into the tissues.

Explain in detail the long term regulation of blood pressure with the RAA pathway.

Be able to list all of the steps of the RAA pathway and ultimately how this pathway changes blood pressure

Blood flow and blood pressure terms to memorize

Practice Questions

1. "An athlete just finished a 1-mile run and sat down to have a drink with her friends. Her blood pressure was not dramatically elevated during the run, but her cardiac output was greatly increased. After the run, her cardiac output decreased dramatically, but her blood pressure only decreased to its resting level. Predict how sympathetic stimulation of the large veins, the arteries in the digestive system, and the arteries in her skeletal muscles changes while she is relaxing. Explain why this is consistent with the decrease in cardiac output." (from Seeley, Stephens, and Tate)

2. A short nursing student is asked to measure the blood pressure of a very tall patient. She decides to measure the blood pressure at the level of the foot while the patient is standing instead of the arm. After taking the blood pressure, she decides that the patient has hypertension because the systolic pressure is 200 mm Hg. Is her diagnosis correct? Why or Why not?

3. During hyperventilation, carbon dioxide is �blown off� and carbon dioxide levels in the blood decrease. What effect does this decrease have on blood pressure? Explain. What symptoms would you expect to see as a result?

4. Why are diuretics and decreasing Na+ in the diet common treatments for high blood pressure? Explain AND diagram!

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