1. Physiology of Circulation

2. Vital signs Arterial pulse Blood pressure Respiratory rate
Pressure wave created by left ventricle after each heart beat
Human average: beats/ minute
Blood pressure
Pressure blood exerts against inner walls of blood vessels (allows blood to keep moving even between heart beats)
Respiratory rate
Breathing rate
Body temperature

3. Arterial Pulse
Body sites where pulse is most easily palpated

4. Blood Pressure Blood moves along a pressure gradient
High  low
Pressure of blood is highest in arteries and decreases as you move from the arteries to arterioles to capillaries to veins
You can tell the difference in pressure of veins versus arteries, when you look at what happens when each are cut

5. Measuring Blood Pressure
Two measurements
Systolic pressure
Pressure in arteries at the peak of ventricular contraction
Diastolic pressure
Pressure when the ventricles are relaxed
Written: systolic pressure / diastolic pressure

6. Effects of Various Factors on Blood Pressure
Cardiac output
Amount of blood pumped out of left ventricle
Determined by stroke volume and heart rate
Peripheral resistance
Friction encountered by blood as it flows through blood vessels
Caused by:
Narrowing/constriction of blood vessels
Increased blood volume or viscosity (thickness)

7. Variation in Blood Pressure
Average Blood Pressure: / 75-80
Hypotension:
Low blood pressure
Systolic below 100
Hypertension:
High blood pressure
Sustained elevated blood pressure of 140/90 or higher

8. Measuring Blood Pressure