Anatomy Lab Chapter 34: Blood Vessels and Blood Pressure

Procedure for Blood Pressure

1.) To determine blood pressure, locate the pulse of the brachial artery on your lab partner. This can be done by placing two fingers on the medial side of the biceps brachii muscle near the antecubital fossa. 2.) Place the blood pressure cuff around the arm of your lab partner at the level of the heart. Make sure the inflatable portion of the cuff is on the anterior medial side. Some cuffs have a metal bar that provides a loop through which a part of the cuff goes through. This bar should not be located on the medial side of the arm. 3.) Clean the ear pieces of the stethoscope with alcohol wipes, place the diaphragm of the stethoscope where you located the brachial pulse, and have your lab partner rest his or her forearm on the lab counter. 4.) Hold on to the rubber squeeze with the attached rubber tubing leading away from you. Turn the metal dial clockwise until it is closed. You can now begin to inflate the cuff. 5.) Pump the cuff up to about 80 mmHg. Look at the mercury in the glass tube or the dial on an aneroid instrument. If it seems to bounce up and down a little, then listen closely for the sound in the stethoscope. If you do no any hear any sound, then inflate the mercury or the dial on an aneroid instrument to 100 or 120 mmHg. If you see the mercury or needle pulsing, listen again for the sound. Make sure the diaphragm of the stethoscope is in the right place. 6.) Once you are sure you have heard the sound of the heart, remove the cuff and place it on the other arm. Excessive constriction of the arm may elevate your lab partner's blood pressure. 7.) Inflate the cuff on the other arm, but make sure you exceed the level where you see motion in the needle or pulsing in the mercury. Do not leave the cuff inflated for a long time. 8.) Release the knob slowly, so that the mercury needle slowly begins to descend. 9.) Record the number when the first sound is heard. This sound represents the systolic pressure of the ventricles, which is the pressure the heart generates that exceeds the pressure of the cuff. This sound may muffle a bit and then come in strong. 10.) Continue to let air out of the cuff slowly until the sound starts to muffle. Listen very carefully until the sound completely disappears. Listen very carefully until the sound completely disappears. The exact level at which the sound disappears is the diastolic pressure.

Normal Blood Pressure in Humans

120/80 mmHg

What is the clinical threshold for high blood pressure in young adults?

140/80 mmHg

The letters bpm stand for what phrase in cardiac measurement?

Beats per Minute

What does a sphygmomanometer measure?

Blood Pressure

To measure blood pressure, what artery would you most commonly use?

Brachial

If you have blood pressure of 140/80, what does the 80 represent?

Diastole

Emotions have an effect on blood pressure. Predict the blood pressure of an individual who recently had a heated argument with a roommate about rent buddy.

Elevated blood pressure

Illness can also affect blood pressure. Illness tends to increase stress response. Predict the blood pressure of an individual with a sinus headache and postnasal drip.

Elevated blood pressure

When the first sound is heard during measurement with a blood pressure cuff, what is measured - systolic or diastolic pressure?

Systolic pressure

Nicotine and caffeine both elevate blood pressure. Explain how an increase in blood pressure could have a negative effect on the cardiac output.

The substances would cause vasoconstriction which can cause elevated blood pressure which causes the heart to pump stronger.