Stroke volume Flashcards
Volume of Blood Pumped per Contraction
stroke volume
Stroke volume equation and average
EDV- ESV
Volume of blood before contraction minus volume of blood after contraction
Average = 70 mL (70-kg man at rest)
What is cardiac output
A measure of cardiac performance
Volume of blood pumped by one ventricle in a given period of time
Cardiac output equation and average of the CO
Cardiac output (CO) = heart rate x stroke volume
Average = 5 L/min
up to 40 L/ per min
Role of the autonomic division
modulates heart rate
What does parasympathetic system control?
- decreases heart rate
- K+ permeability increases
- Pacemaker potential begins at a lower value
- permeability decreases
-Slows rate of pacemaker depolarization
What does the sympathetic system control?
- increases heart rate
- β1-adrenergic receptors on the autorhythmic cells
-Na+ and Ca2+ permeability increases
Which system normally dominates tonic control
parasympathetic activity
Which stimulation decreases heart rate
parasympathetic nerves
Which stimulation increases heart rate
sympathetic nerves