BIO 436 CV Dynamics Mini Exam
Questions and Correct Answers
Cardiac output (CO) ✅heart rate * stroke volume
(HR x SV)
Cardiac output is the amount of blood pumped out by each ventricle in one minute.
Cardiac output is directly related to heart rate and stroke volume.
End diastolic volume (EDV) ✅The maximum amount of blood in the ventricles
occurs at the end of ventricular relaxation (diastole- heart chamber fills)
stretches sarcomeres back to ideal resting length
~135 mL
Stroke volume (SV) ✅amount of blood that is ejected from the ventricles
SV = EDV- ESV
Factors that affect:
-preload
-contractility
-afterload
Myocardium ✅the muscular tissue of the heart
End systolic volume (ESV) ✅minimum amount of blood in the ventricles after
contraction
~65 mL
Semilunar valve ✅aortic and pulmonary valves
Bicuspid/mitral valve ✅Left AV valve
Tricuspid valve ✅Right AV valve
Cardiac cycle ✅mechanically whats happening with the heart
1. all chambers are at rest (late diastole; passive filling)
2. atrial systole (active filling)
3. IVC (AV Valves close "lub")
4. Ventricular ejection
5. Isovolumetric ventricular relaxation (Semilunar Valves close dub")
Ventricular systole ✅during which the ventricles are pumping (or ejecting) blood out of
the heart through the aorta and the pulmonary veins. (contraction of heart)
, Isovolumetric contraction ✅first phase of ventricular contraction pushes AV valves
closed, but does not create enough pressure to open semilunar valves
Isovolumetric relaxation ✅as ventricles relax, pressure in ventricles drops, blood flows
back into cups of semilunar valves and snaps them closed.
Ventricular ejection ✅as ventricular pressure rises and exceeds pressure in the
arteries, the semilunar valves open and blood is ejected
Pulmonary artery ✅carries deoxygenated blood to the lungs
Pulmonary vein ✅carries oxygenated blood back to the L atria from the lungs
Frank-Starling law of the heart ✅the more blood that is put into the heart, the more
blood is ejected
due to sarcomere ideal resting length
(a) is state of myocardial sarcomeres just before filling
- Actins overlap, actin-myosin interactions are reduced & contraction would be weak
• In (b, c & d) there is increasing interaction of actin & myosin allowing more force to be
developed
Venous return ✅Is return of blood to heart via veins
Controls EDV & thus SV & CO
Dependent on:
- Blood volume &
venous pressure
- Vasoconstriction of VEINS caused by Symp
- Skeletal muscle pumps
- Pressure drop during inhalation
Resistance vessels ✅A resistance artery is small diameter blood vessel in the
microcirculation that contributes significantly to the creation of the resistance to flow and
regulation of blood flow.
Vasoconstriction ✅-Contraction of the smooth muscle of the blood vessel, results in
decreased blood vessel radius
Increase NE on
-Alpha Receptor
Decrease NE on
-Beta Receptor
Vasodilation ✅Decrease NE on
-Alpha Receptor
Increase NE on
-Beta Receptor
Questions and Correct Answers
Cardiac output (CO) ✅heart rate * stroke volume
(HR x SV)
Cardiac output is the amount of blood pumped out by each ventricle in one minute.
Cardiac output is directly related to heart rate and stroke volume.
End diastolic volume (EDV) ✅The maximum amount of blood in the ventricles
occurs at the end of ventricular relaxation (diastole- heart chamber fills)
stretches sarcomeres back to ideal resting length
~135 mL
Stroke volume (SV) ✅amount of blood that is ejected from the ventricles
SV = EDV- ESV
Factors that affect:
-preload
-contractility
-afterload
Myocardium ✅the muscular tissue of the heart
End systolic volume (ESV) ✅minimum amount of blood in the ventricles after
contraction
~65 mL
Semilunar valve ✅aortic and pulmonary valves
Bicuspid/mitral valve ✅Left AV valve
Tricuspid valve ✅Right AV valve
Cardiac cycle ✅mechanically whats happening with the heart
1. all chambers are at rest (late diastole; passive filling)
2. atrial systole (active filling)
3. IVC (AV Valves close "lub")
4. Ventricular ejection
5. Isovolumetric ventricular relaxation (Semilunar Valves close dub")
Ventricular systole ✅during which the ventricles are pumping (or ejecting) blood out of
the heart through the aorta and the pulmonary veins. (contraction of heart)
, Isovolumetric contraction ✅first phase of ventricular contraction pushes AV valves
closed, but does not create enough pressure to open semilunar valves
Isovolumetric relaxation ✅as ventricles relax, pressure in ventricles drops, blood flows
back into cups of semilunar valves and snaps them closed.
Ventricular ejection ✅as ventricular pressure rises and exceeds pressure in the
arteries, the semilunar valves open and blood is ejected
Pulmonary artery ✅carries deoxygenated blood to the lungs
Pulmonary vein ✅carries oxygenated blood back to the L atria from the lungs
Frank-Starling law of the heart ✅the more blood that is put into the heart, the more
blood is ejected
due to sarcomere ideal resting length
(a) is state of myocardial sarcomeres just before filling
- Actins overlap, actin-myosin interactions are reduced & contraction would be weak
• In (b, c & d) there is increasing interaction of actin & myosin allowing more force to be
developed
Venous return ✅Is return of blood to heart via veins
Controls EDV & thus SV & CO
Dependent on:
- Blood volume &
venous pressure
- Vasoconstriction of VEINS caused by Symp
- Skeletal muscle pumps
- Pressure drop during inhalation
Resistance vessels ✅A resistance artery is small diameter blood vessel in the
microcirculation that contributes significantly to the creation of the resistance to flow and
regulation of blood flow.
Vasoconstriction ✅-Contraction of the smooth muscle of the blood vessel, results in
decreased blood vessel radius
Increase NE on
-Alpha Receptor
Decrease NE on
-Beta Receptor
Vasodilation ✅Decrease NE on
-Alpha Receptor
Increase NE on
-Beta Receptor
