CV System review Flashcards
Primary function of the CV system
Deliver oxygenated blood to tissues
Return deoxygenated blood to heart
What part of the vascular system is this?
- Carries oxygenated blood from the heart to the tissues
- High-pressure system
- Artery>Arteriole>Capillaries
Arterial system
What part of the vascular system is this
- Oxygen and nutrients delivered to tissues
- Cellular waste removed from tissues
- Capillaries are abundant in body
Capillary bed
What part of the vascular system is this
- Contains valves to prevent backflow
- Carries blood back to heart
- Low-pressure system
- Veins>Venules>Capillaries
Venous system
Blood supply to the heart 1
Left coronary artery
Branches of Left coronary artery
- Left anterior descending (LAD) branch
- Circumflex branch
What supplies these areas with blood?
- Both ventricles
- Anterior interventricular septum
- Anterior wall of the heart
- Left atrium
- Posterior wall of the left ventricle
Left coronary artery
Blood supply to the heart 2
Right coronary artery
branches in the right coronary artery
- Right marginal branch
- Posterior Interventricular branch
What supplies these areas with blood?
- Lateral aspect of right atrium and ventricle
- Posterior aspect of both ventricles and interventricular septum
Right coronary artery
Receives deoxygenated blood
Right Atrium
- Receives blood from right atrium
- Then goes to lungs (pulmonary artery
Right Ventricle
Receives oxygenated blood from lungs
Left Atrium
- Receives blood from left atrium (pulmonary vein)
- Then out the Aorta to systemic circulation
Left Ventricle
- located between the atrium and ventricles.
- When they open blood flows from atria to ventricles
- When they close it prevents backflow of blood
Atrioventricular Valves
facilitate one-way flow of blood
Heart Valves
located between ventricles and their respective arteries
Semilunar valves
Chambers of the heart
Right Atrium
Right Ventricle
Left Atrium
Left Ventricle
Layers of the heart
- Epicardium
- Mycardium
- Endocardium
thin, outer layer of the heart
Epicardium
thick, middle layer of the heart. Responsible for contracting
Mycardium
thin, inner layer of heart and valves
Endocardium
Order of cardiac conduct system
- SA node fires
- AV node
- Bundle of His
- Right and left bundle branches
- Purkinje fibers
Process in which the membrane potential, the difference in charge between the interior and exterior of the cell, changes or goes up and down in a consistent pattern.
Cardiac action potential
Movement of ions preceding and facilitating cardiac mechanical contraction.
Depolarization
The movement of ions back to the resting state, the cardiac resting membrane potential of –90 mV, to allow for the initiation of another action potential.
Repolarization
The cell is unresponsive to any stimulus.
Absolute refractory period
T greater-than-normal stimulus may initiate an impulse
Relative refractory period
How can action potential’s response be measured?
EKG or ECG
Blood ejected from left side of the heart each minute to facilitate the delivery of oxygen & nutrients to the tissues
Cardiac Output
4 Determinants of Cardiac Output
- Heart Rate (HR)
- Preload
- Afterload
- Contractility
Cardiac output formula
HR X SV(stroke volume) = CO
Normal CO in adults
4 to 7 L/min
The amount of blood ejected with each ventricular contraction. Comprised of the preload, afterload, and contractility.
Stroke volume
The amount of blood returned to the right side of the heart at the end of diastole
Preload
Pressure that the left ventricle has to pump against or the resistance it must overcome to circulate blood
Afterload
Force / strength of contraction of the heart muscle
Contractility
Increase afterload causes….
decreases stroke volume, decreases CO
Decrease afterload
increases stroke volume, increases CO
Increase in cardiac output will promote _______
Blood flow
Decrease in cardiac output will decrease ________
blood flow
What can decrease contractility?
Hypoxia or acidosis
What can increase contractility
Release of calcium or sympathetic stimulation
Decreased cardiac output indicates what?
- Less volume
- Decreased perfusion to vital organs
Increased cardiac output
- More volume
- Can be caused by hypervolemia
Normal EF
50-70%
% of blood expelled from the left ventricle with every contraction
EJECTION FRACTION or EF
How can afterload be measured?
Systolic BP
Carries deoxygenated blood to the lungs
Right side of heart
Carries oxygenated blood to the rest of the body
Left side of heart
