Lecture 3 - Jan 23 Flashcards
What are the two components that determine cardiac output?
Health of the heart and health of the system
What is the normal right atrial pressure under healthy conditions?
Zero
What does delta p represent in the context of venous return?
The difference between systemic pressure and right atrial pressure
What is indicated by a low resistance to venous return?
An easy pathway for blood to return to the heart
What happens to venous return if right atrial pressure increases?
Venous return decreases
What is the effect of a hyper effective heart on right atrial pressure?
It decreases right atrial pressure
How does an increase in systemic filling pressure affect venous return?
It increases venous return
Fill in the blank: The systemic filling pressure is defined by the point at which the venous return curve runs into the _______.
X-axis
What effect does positive pressure ventilation have on venous return?
Decreases venous return
What is phenylephrine used for in the venous system?
To tighten up the veins
What is the maximum cardiac output under normal conditions?
13 L/min
What can sympathetic stimulation do to cardiac output?
Increase it significantly
True or False: Removing sympathetic stimulation has a significant effect on cardiac output in a healthy heart.
False
What happens to cardiac output during maximum parasympathetic stimulation?
It reduces cardiac output
What is the impact of a myocardial infarction (MI) on cardiac output?
Reduces cardiac output significantly
How does a hypo-effective heart affect right atrial pressure?
It increases right atrial pressure
What typically happens to the right atrial pressure in heart failure?
It increases
What compensatory mechanism does the body use to address heart problems?
Increases filling pressures
What is the relationship between systemic filling pressure and cardiac output?
Higher systemic filling pressure increases cardiac output
What occurs when the circulatory system compensates for heart problems?
It increases systemic filling pressure to enhance cardiac output
Fill in the blank: The right atrial pressure is often elevated in patients with _______.
Heart problems
What happens to the venous return curve when systemic filling pressure is increased?
Shifts to the right
What does a weak heart imply for cardiac output and right atrial pressure?
Lower cardiac output and higher right atrial pressure
What happens to right atrial pressure without compensation?
It is only 3
This indicates a normal physiological state without compensatory mechanisms in place.