Physiology - Cardiopulmonary Flashcards
What bundle conducts the cardiac impulse from the right atrium to left atrium?
Where is the SA node located
Bachmann Bundle
situated in the upper part of the wall of the right atrium
What are mechanoreceptors that detect changes in pressure?
Baroreceptors
What reflex results from an increase in venous return that stretches the wall of the right atrium sending vagal afferent signals to the cardiovascular center within the medulla?
What is its effect?
Bainbridge Reflex
Inhibits parasympathetic activity resulting in increased heart rate
What reflex has chemosensitive cells in the aortic body that respond to changes in pH to stimulate respiratory centers and activates teh parasympahtetic system?
What is its affect? (2)
Chemorecptor reflex
increases depth and rate of ventilation
reduced HR and myocardial contractility
Normal stroke volume and cardiac output?
stroke volume: 60-80 mL
Cardiac Output: 4.5 - 5.0 L/min
What structures carry deoxygenated blood from the heart to the lungs?
pulmonary arteries
What happens when central chemoreceptors in the medulla respond to increases in partial pressure of CO2 and hydrogen ions?
increased ventillation
80-90% of carbon dioxide ions are transported by the blood as what?
bicarbonate ions
What is an index of myocardial oxygen consumption and coronary blood flow?
Rate Pressure Product AKA double-product
What is the procedure for measuring Rate Pressure Product?
- measure SBP and HR during the same exercise workload
- RPP = HR x SBP
usually reported as a two digit number x 10^3
25.5 x 10^3 = (150) x (170)
The Rate Pressure Product is a reproducible measure that correlates with what? (2)
- onset of angina pectoris
2. development of ECG abnormalities in patients with heart disease
What are the two things measured to calculate Rate Pressure Product?
HR and SBP
