Cardiac Output Flashcards
Formula for Cardiac Output
CO = SV (stroke volume) x HR (heart rate)
Formula for Cardiac Output
CO = SV (stroke volume) x HR (heart rate)
What 2 systems affect the HR and SV?
The Nervous System and Reflex arcs
-these are extrinsic regulatory systems
What 2 systems affect the HR and SV?
The Nervous System and Reflex arcs
-these are extrinsic regulatory systems
What system only mediates SV?
The Primary intrinsic system or Frank Starling mechanism
What system only mediates SV?
The Primary intrinsic system or Frank Starling mechanism
Things that increase HR?
exercising
emotion
altitude
Things that increase HR?
exercising
emotion
altitude
Things that decrease HR?
digestion (homeostasis)
pleasure after exercise
Things that decrease HR?
digestion (homeostasis)
pleasure after exercise
What are the 3 determinants of SV?
EDV
ESV
Preload (Starling’s Law)
What are the 3 determinants of SV?
EDV
ESV
Preload (Starling’s Law)
Preload
- The amount of blood that goes into the ventricles
- Filling takes place
- slight increase in sarcomere length
Preload
- The amount of blood that goes into the ventricles
- Filling takes place
- slight increase in sarcomere length
- affects EDV
Afterload
-the amount of pressure that the ventricle must overcome to pump blood out
Afterload
-the amount of pressure that the ventricle must overcome to pump blood out
Venus return
- filling pressure
- pre-load
Venus return
- filling pressure
- pre-load
Calcium is crucial for what?
The binding of actin myosin
Calcium is crucial for what?
The binding of actin myosin
increase SV and CO means?`
increased preload and contractility
increase SV and CO means?`
increased preload and contractility
decreased SV and CO from?
-increased afterload
decreased SV and CO from?
-increased afterload
Most important regulatory system governing heart rate is?
- the Medullary Oblongata
- it responds to changes in arterial pressure with changes in heart rate in parallel with changes in contractility
Most important regulatory system governing heart rate is?
- the Medullary Oblongata
- it responds to changes in arterial pressure with changes in heart rate in parallel with changes in contractility
Decreased blood pressure leads to what?
- increased contractility (increased sympathetic tone)
- increased heart rate (decreased parasympathetic tone)
Decreased blood pressure leads to what?
- increased contractility (increased sympathetic tone)
- increased heart rate (decreased parasympathetic tone)
Increased blood pressure leads to what?
- decreased contractility
- decreased heart rate
Increased blood pressure leads to what?
- decreased contractility
- decreased heart rate
Parasympathetic fibers
-Vagus Nerve (motor) - SA node and AV node
Parasympathetic fibers
-Vagus Nerve (motor) - SA node and AV node
Sympathetic Fibers
- signal from spinal cord T1-L2 interomedialateral horn
- exits out chain ganglion and goes to arch of aorta
Sympathetic Fibers
- signal from spinal cord T1-L2 interomedialateral horn
- exits out chain ganglion and goes to arch of aorta
Glossopharyngeal Nerve
-carotid sinus and carotid body (sensory)
Glossopharyngeal Nerve
-carotid sinus and carotid body (sensory)
Vagus (sensory)
-from the aortic sinus and aortic body
Vagus (sensory)
-from the aortic sinus and aortic body
Intrinsic Regulation
- threshold potential
- maximal diastolic potential
- slope of diastolic depolarization
Intrinsic Regulation
- threshold potential
- maximal diastolic potential
- slope of diastolic depolarization
Extrinsic Regulation
- hormones
- autonomic nervous system
Extrinsic Regulation
- hormones
- autonomic nervous system
Ventricular Compliance
-ability of ventricles to take on extra blood
Ventricular Compliance
-ability of ventricles to take on extra blood
What affects End-diastolic volume?
- filling pressure
- filling time
- ventricular compliance
What affects End-diastolic volume?
- filling pressure
- filling time
- ventricular compliance
What affects End-systolic volume?
- heat rate
- pre-load
- after-load
- contractility
What affects End-systolic volume?
- heat rate
- pre-load
- after-load
- contractility
Cardiac Output affects what?
- mean arterial pressure
- venous return
Cardiac Output affects what?
- mean arterial pressure
- venous return