Lecture 10: CONTROLLING THE HEART AND BLOOD PRESSURE Flashcards
What does the left ventricle do?
Generate pressure for the systemic circulation
What is the pressure in large systemic arteries?
High
What is the pressure in the systemic circuit linked to?
Ventricular contraction and ejection of blood
Where is the blood pressure pulsatile?
In major arteries (systolic/diastolic)
What is MAP?
Mean arterial pressure
What is mean arterial pressure?
A critically important determinant of blood flow
What is the blood pressure in major arteries?
High
Where is the blood pressure oscillatory?
In major arteries because of blood being ejected from the heart and this nature is reduced in the arterioles, capillaries and venules
Where does blood pressure fall steeply?
Across the arterioles, capillaries and venules
What is the blood pressure in veins?
Very low
Where is there a large difference in pressure?
Between arterial and venous sides
What does the large difference in pressure between arterial and venous sides do?
Create a driving force for blood flow
What does ejection of blood into the arterial system do?
Maintains arterial blood volume and blood pressure
What is the result of blood flowing?
Filling arteries, increasing arterial blood volume and raising arterial pressure
What is the result of blood flowing out?
Drains arteries, decreases arterial blood volume and lowers arterial pressure
What is arterial blood volume and pressure determined by?
Balance between blood flows in and out
What actions happen when blood flows in?
Ventricular contraction and ejection of blood (cardiac output)
What is cardiac output?
Flow of blood out of ventricles into arteries per unit of time
What actions happen when blood flows out?
Capillary flow
What is blood flow out controlled by?
Resistance of the arteries
How can arterial volume and pressure be increased?
Increased cardiac output (increase in flow) and increased resistance (decrease outflow)
What is MAP equal to?
Cardiac output (CO) x Total Peripheral Resistance (TPR)
What is cardiac output determined by?
Stroke volume and heart rate
What is cardiac output equal to?
Stroke volume x Heart rate