1. Blood Pressure and Heart Rate
KAAP 310 Lab

2. Autorhythmiticity The heart triggers its own contractions
Due to permeability to Potassium ions
Slow leakage of Sodium and Calcium

3. Cardiac Action Potential

4. Pacemakers Primary: Sinoatrial node (SA node) (60-100 BPM)
Secondary: atrioventricular node (AV) (40-60 BPM)
Tertiary: bundle of His (30-40 BPM)
Last: Purkinje Fibers (under 30 BPM)

5. Nervous System Sympathetic: increases HR/BP
Increases with inhalation
Parasympathetic: decreases HR/BP
Increases with exhalation

6. Measuring HR Pointer and middle finger together Use radial artery
Count beats starting at 0 for 15 seconds and multiply by 4
Who knows why you wouldn’t use your thumb? It has its own heart beat

7. Heart rate ranges Normal 60-100 BPM (unless endurance athlete)
Bradycardia: under 60 BPM
Tachycardia: over 100 BPM
Cardiac output= heart rate * stroke volume
Why, then, can endurance athletes have a resting heart rate less than 60 BPM but still maintain the same cardiac output as somebody without training?

8. What is Blood Pressure?
Force exerted by blood on arterial walls during cardiac cycle
Systolic – force during contraction
Diastolic – force during relaxation
BP = Q x Total Peripheral Resistance (TPR)
Amount of blood (Q)
Resistance to flow (TPR)
Typically measured through brachial artery
Unit of measure is mmHg

9. Blood Pressure Normative Values
Category
Systolic (mmHg)
Diastolic (mmHg)
Normotensive
< 120
< 80
Pre-Hypertensive
80-89
Hypertension (Stage 1)
90-99
Hypertension (Stage 2)
> 160
> 100
*According to American Heart Association (AHA)

10. Measuring Blood Pressure
Antecubital region (elbow pit)
Stethoscope with ear pieces ‘forward’
Drum turned ‘on’
Arm is resting on table and at heart level
Inflate to pulse obliteration pressure
Deflate at 2-4 mmHg/second
Listen very carefully
NOTE: show video!

11. Lab activity Get in groups
Follow steps and make sure each person gets a chance to take HR and BP
Homework
BP questions due next week by start of lab (1 per group)
Study Lesson 5 Introduction of Biopac (EKG)
Short quiz to start class
Bring Lesson 5 with you next week