Circulation & Perfusion Flashcards
What 3 types of vessels makes up the vascular system?
Arteries, veins, and capillaries
All vessels are lined with what?
Smooth endothelial layer
What % of oxygen is bound to hemoglobin?
97%
T/F. The coronary arteries are the only arteries that fill during diastole ?
True
The ANS regulates cardiovascular function through its influence on what 2 things?
The heart and vascular system
What are baroreceptors?
Located in the walls of the heart and blood vessels. They sense blood pressure changes. If BP is low they will send signals to brain to stimulate SNS and increase HR and induce vasoconstriction.
What kind of receptors does the vascular system have to sense changes in blood pH, oxygen, and CO2?
Chemoreceptors
What is MAP?
Mean arterial pressure calculation that checks whether there’s enough blood flow, resistance, and pressure to supply blood to the major organs.
Most people need a MAP of how many mmHg to ensure enough blood flow to vital organs?
At least 60mmHg or greater
What is considered a high MAP meaning that there is a lot of pressure in the arteries?
Anything over 100mmHg
Why is a MAP under 60mmHg bad?
Because blood may not be reaching organs
What is pre load ?
Think volume
Pressure of blood entering the heart. Amount of blood in the ventricles at the end of diastole.
What is after load ?
Think resistance
Pressure of blood leaving the heart. So increase vascular resistance will increase after load.
What is stroke volume?
Amount of blood ejected with each ventricular contraction
What 3 factors affect stroke volume?
Contractility, pre load, and after load.
How is cardiac output calculated?
HR x SV
What is a normal cardiac output ?
4-7 L/min
What is the appropriate diagnosis when the heart is unable to pump adequate amounts of blood to meet metabolic demands of the body?
Decreased cardiac output
When does cardiac output increase?
With exercise or activity
When does cardiac output decrease?
Times of rest
What is a normal EF?
More than 55%
What is EF?
Amount of blood that is pumped out of the left ventricle with each contraction
Why do HF patients have a EF less than 40%?
Msl of left ventricle is not pumping as well
What 6 factors influence cardiac function?
Developmental stage, environment, lifestyle, substance abuse, medications, and patho physiological conditions.
Why does cardiac efficiency gradually decline in older adults?
Thicker and more rigid valves, decreased myocardial strength, lower exercise tolerance, more prone to orthostatic hypotension.
At what intervals do we take orthostatic vital signs?
1-3 minutes after each change of position
What neurotransmitter is released from the SNS with stress?
Catecholamines
How does heat influence cardiac output?
Causes vasodilation which increases cardiac output and oxygenation. Also increases metabolism.