Parts of the heart
Four heart Chambers
right and left atrium
right and left ventricles
Opening between right ventricle and pulmonary trunk
pulmonary semilunar valve
what drains the oxygen poor blood from myocardium
coronary sinus
Calculate the CO of:
HR = 75 beats/min
SV = 70 mL
Systolic BP = 124 mmHg
Diastolic BP = 76 mmHg
CO = HR x SV
CO = 75bpm x 70 mL
CO = 5250 mL/min
CO = 5.25 L/min
Which atrium receives deoxygenated blood
right atrium
Opening between left ventricle and aorta
aortic semilunar valve
explain the cardiac conduction system
1.Sinuatrial (SA) node: pacemaker, in right atrium; initiates heartbeat
•ectopic focus: a region of spontaneous firing other than the SA node if it is damaged (usually AV node)
2.Signals spread throughout atria
3.Atrioventricular (AV) node: near the right AV valve at lower end of interatrial septum, spreads signal to ventricles
4.Atrioventricular (AV) bundle (bundle of His): carries signal away from AV node, forks into right and left bundle branches
5.Purkinje fibers: spread signal throughout ventricles
Calculate the CO of
HR = 75 beats/min
EDV = 140 mL
ESV = 80 mL
Systolic BP = 120 mmHg
Diastolic BP = 82 mmHg
CO = HR x SV SV = EDV-ESV
CO = 75 bpm x ____ SV = 140mL-80mL
CO = 75 bpm x 60mL SV = 60 mL
CO = 4500 mL/min
CO = 4.5 L/min
Which ventricle is the pulmonary trunk
right ventricle
What delivers oxygen rich blood to the heart
right and left coronary arteries
Phase 0- when signal reaches cell it causes fast influx of sodium ions, cause memb potential to change approx -90 to +20 mV generating action potential
phase 1- cells start to depolarize but only for brief period
Phase 2- plates phase where cell remains depolarized.
3- cells depolarize as pottassium leaves and potential to its original resting value
4- resting membrane potential of the cell (-90mV)
A patient has a stroke volume (SV) of 70 mL/beat and a heart rate (HR) of 80 beats/minute. Calculate the cardiac output (CO).
Given:
Cardiac Output (CO) is given by the formula:
CO=SV×HRCO=SV×HRSubstituting the values:
CO=70 mL/beat×80 beats/minCO=70mL/beat×80beats/minCO=5600 mL/minCO=5600mL/minConverting to liters:
CO=5.6 L/minCO=5.6L/minWhat is the left ventricle
aorta
Oxygenated blood flow from lungs
pulmonary veins to left atrium to bicuspid valve to left ventricle to aortic valve to aorta to body organs
Explain the parts of the ECG
•P wave: represents atrial depolarization when signals from SA node spread through atria
•QRS complex: represents ventricular depolarization when signals from AV node spread through ventricles
•T wave: represents ventricular repolarization when ventricles relax
•PR Interval: time it takes impulses to travel from atria to ventricles
•QT interval: time it takes ventricles to contract and relax
A patient has a cardiac output of 5.5 L/min and a heart rate of 75 beats/minute. Calculate the stroke volume.
Given:
Rearranging the formula:
SV=COHRSV=HRCO
Converting CO to mL/min:
CO=5500 mL/minCO=5500mL/min
Substituting values:
SV=5500 mL/min75 beats/minSV=75beats/min5500mL/minSV=73.33 mL/beatSV=73.33mL/beat
What are the AV valves and which side are they on
tricuspid-right
bicuspid- left
Deoxygenated blood flow from organs
SVC IVC CS to right atrium to right av valve (tricuspid) to right ventricle to pulmonary valve to pulmonary trunk to pulmonary arteries
What are the phases of the cardiac cycle
. Ventricular Filling: ventricles are relaxed and blood pours from atria into ventricles
•End-diastolic volume (EDV): max volume ventricles can hold (130 mL)
2. Isovolumetric Contraction: ventricles contract to increase pressure enough that they can force semilunar valves open. No blood ejected out
3. Ventricular Ejection: ventricles contract and blood ejected out through semilunar valves and into pulmonary trunk and aorta
•Stroke volume (SV): blood ejected out of ventricles (70 mL)
•End-systolic volume (ESV): blood left in ventricles (60 mL
4. Isovolumetric Relaxation: all heart valves closed so no blood enters or leaves chambers. Ventricles expand and relax to start the cardiac cycle over
Convert a cardiac output of 6,000 mL/min to L/min and determine the heart rate if the stroke volume is 75 mL/beat.
Given:
Converting to liters:
CO=6000 mL/min=6 L/minCO=6000mL/min=6L/min
Calculating Heart Rate (HR):
HR=COSVHR=SVCOHR=6000 mL/min75 mL/beatHR=75mL/beat6000mL/minHR=80 beats/minHR=80beats/min