Pulse and Blood Pressure

Pulse Pulse pressure wave of blood Measured as Heart Rate: beats per minute Monitored at “pressure points” where pulse is easily palpated Figure 11.16 Slide 11.35 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Practice taking your pulse and Heart Rate First, try to find your pulse Neck: just below the corner of your mandible Wrist: on the thumb side, between the tendons Now, count how many beats you feel in 60 seconds. I’ll time you

Blood Pressure Measurements by health professionals are made on the pressure in large arteries Systolic – pressure at the peak of ventricular contraction Diastolic – pressure when ventricles relax Pressure in blood vessels decreases as the distance away from the heart increases Slide 11.36 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Comparison of Blood Pressures in Different Vessels Figure 11.17 Slide 11.38 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Quick Quiz Why do you think it is important to measure pulse and heart rate? What does blood pressure measure? Why do you think it is important to monitor blood pressure?

Measuring Arterial Blood Pressure Figure 11.18 Slide 11.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Blood Pressure Demonstration

Blood Pressure: Effects of Factors Peripheral Resistance The amount of friction encountered by blood as it flows through blood vessels Constriction/narrowing of vessels Blood viscosity (thickness) Cholesterol buildup inside vessels Age, weight, exercise, body position, emotional state, drugs Slide 11.39a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Blood Pressure: Effects of Factors Neural factors Autonomic nervous system adjustments (sympathetic division) Renal factors Regulation by altering blood volume Renin – hormonal control Slide 11.39a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Blood Pressure: Effects of Factors Temperature Heat has a vasodilation effect Cold has a vasoconstricting effect Chemicals Various substances can cause increases or decreases Diet Slide 11.39b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Factors Determining Blood Pressure Figure 11.19 Slide 11.40 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Quick Quiz What is Peripheral Resistance? Name two factors that influence Peripheral Resistance.

Variations in Blood Pressure Human normal range is variable Normal 140–110 mm Hg systolic 80–75 mm Hg diastolic Hypotension Low systolic (below 110 mm HG) Often associated with illness Hypertension High systolic (above 140 mm HG) Can be dangerous if it is chronic Slide 11.41 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Developmental Aspects of the Cardiovascular System A simple “tube heart” develops in the embryo and pumps by the fourth week The heart becomes a four-chambered organ by the end of seven weeks Few structural changes occur after the seventh week Slide 11.44 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Quick Quiz Would 120/80 be considered a normal blood pressure? When systolic pressure is greater than 140, what is the condition called? When systolic pressure is less than 110, what is the condition called? What do you think the dangers of high or low blood pressure are?