Control of Heartbeat and Monitoring Blood Pressure. Learning objectives. Define heart rate, stroke volume & cardiac output List the main factors affecting blood pressure Measure & accurately record heart rate & blood pressure, using equipment safely. Control of Heartbeat – a review.
On your mini whiteboards, summarise what you remember about this!
Heart rate = # beats
Stroke Volume = blood cm3
Cardiac Output = blood cm3 X # beats = blood
beat minute minute
Parasympathetic & sympathetic nerves
to smooth muscle of arterioles
What is the effect of exercise on cardiac output?
Get out your calculators!
1. Place the stethoscope ear pieces around your neck and wrap the cuff of your sphygmomanometer tightly around your upper arm.
2. Locate the pulse of your brachial artery by tracing your finger down your bicep down toward the crook, or inside elbow, of your arm. You should find the brachial pulse about an inch or so above this crook.
3. Put the ear pieces of the stethoscope into your ears and place the round, metal end of the stethoscope over the pulse of your brachial artery.
4. Tighten the stopcock on the sphygmomanometer bulb and squeeze the bulb of your sphygmomanometer multiple times to inflate the cuff around your upper arm. The cuff should be inflated until you've reached 180 mm of pressure. You will be able to determine how much pressure you've pumped into the sphygmomanometer cuff by reading the blood-pressure meter in front of you.
5. Release the bulb stopcock slowly and gradually. This will let the air out of the cuff, allowing you to make a blood pressure reading.
6. Note the number on the meter when you first hear your pulse through the stethoscope. Then note the number when the last pulse sound comes through the stethoscope. Record these two numbers by placing the higher number over the lower number to determine your current blood pressure.