Cardiovascular Physiology 18 Flashcards
What is an important difference between the left and right ventricle?
The right ventricle does not develop pressures as great as the left ventricle
When is Pressure generated?
When the muscles of the heart contract and when a chamber fills with blood
What is the direction of the flow of blood?
Blood always flows from a region of higher pressure to a region of lower pressure
What do Heart Valves open and close in response to?
A pressure gradient
Which pressure gradients open and shut valves?
A forward pressure gradient opens a valve and a backwards pressure gradient closes a valve
What is the End-diastolic volume (EDV)?
The amount of blood in each ventricle at the end of ventricular diastole
What is the End-systolic volume (ESV)?
The amount of blood in each ventricle at the end of ventricular systole
What is Stroke Volume?
The volume of blood pumped out of each ventricle during systole
How can SV be calculated?
SV = EDV - ESV
What is the typical stroke volume for an adult at rest?
70 75 mL
When will stroke volume increase or decrease?
It will increase during exercise and decrease during rest
What does the P wave signify on wiggers diagram?
Atria contraction ejecting a little more blood into the ventricle
When does the EDV measure?
After atrial contraction pumps a little more blood into the ventricles
What does the QRS complex signify on wiggers diagram?
Ventricular contraction
When is ESV measured?
After the ventricle ejects its blood into the AOrta and pulmonary artery
What is higher EDV or ESV?
EDV is higher because it is measured when the ventricle is filled with blood before the ventricle contracts
Why are very small pressure differences observed by the ventricle and aorta?
Because the aorta offers little resistance to flow
What does the T wave on the ECG signify?
The ventricles entering diastole
What is first heart sound caused by?
Closure of the AV valves at the beginning of Isovolumetric Ventricular contraction
What does the Lub sound signify?
The onset of ventricular systole
What is the second heart sound caused by?
The closure of the Semilunar valves
What does the second heart sound signify?
The onset of ventricular diastole
