Chapter 5D - Cardiovascular System Flashcards
Describe the pump
The left heart pumps blood into the systemic circulation at the maximum pressure called “systolic pressure” varies from 100-140mmHg in healthy people.
Describe the primary function of the cardiovascular system
To supply the body with oxygenated blood containing the nutrients needed for metabolism, and to carry away the waste products
Describe the pipes
The arteries, arterioles, and capillaries that deliver blood to the body’s cells under pressure (diastolic pressure) varies from 60-90 mmHg
Venules and veins being blood back to the heart at very low pressure
Describe the fluid
The blood
Describe the right heart
The pulmonary heart
Receives the venous return of deoxygenated blood from the vena cava (preload) and pumps it to the lungs
Pump at lower BP than left heart
<30 mmHg systolic
+_ 10-20mmHg diastolic
Describe left heart
Systemic heart
Receives venous return of oxygenated red blood from the lungs and pumps it to the rest of the body.
There is much more resistance in all of the body’s arteries. (Afterload) so it has to work harder
Has greater coronary blood flow
Greater than or equal to 120mmHg systolic
Greater than or equal to 70mmHg diastolic
Gets 75% of all clots in MIs
If right heart is damaged?
Not able to deal with all of the venous return (preload) and that will cause this return to “back up” into the veins - overtime result in dependent edema.
If left heart damaged?
It will not be able to deal with all of the venous return from the lungs
Will cause a “back up” resulting in pulmonary edema
Explain “the amount of blood in the body occupies 1/5 of the available space “
The blood vessels are always fairly tightly constricted. If the “pipes” do not stay tightly constricted. You will go into shock, and/or faint.
If you have 5 quarts of blood, then if all vessels dilated at once it will take 25 quarts to fill them
How much blood does a person have?
A person has 1 quart of blood for every 30 pounds of body weight.
5-6 quarts for people weighing 150-180lbs
How much blood loss produces shock?
Loss of 15% of blood volume produces moderate shock
30% produces severe shock
Cardiac output
CO = SV x HR
Is the cardiac minute volume, the amount of blood pumped by the heart (left ventricle) in one minute. It is the same as the Stroke volume times the heart rate.
Define stroke volume
The amount of blood ejected by the left ventricle with each heart beat
Heart rate
Number of heartbeats per minute
Define ejection fraction
The percentage of blood in the ventricles that is linked out per beat
Usually 60%, but in CHF 20%
Define peripheral vascular resistance PVR
Pumping pressure of the arteries and arterioles - is is another way of saying Diastolic pressure. It is largely determined by the diameter of the blood vessels and their muscle tone.
Also called after load because it is the pressure the ventricles must beat against
Define diastolic pressure
The lower number in a blood pressure ( PVR)
Systolic pressure
Upper number of BP = the pumping pressure of the heart
Pulse pressure
Difference between the systolic and diastolic pressures (about 40-50mmHg)
Define Starling’s Law of the Heart
Says that within limits, the force of the heart’s contractions is primarily determined by diastolic filling - better the filling, the greater the stretch, the stronger will be the contraction
Based upon preload, the amount of venous return.
Define tachycardia
An abnormally rapid pulse rate = greater than or equal to 100 in adults
- usually indicates insufficient perfusion, so the heart speeds up to compensate.
Define bradycardia
An abnormally rapid pulse = less than or equal to 60 in adults
- may indicate several things, downer drug abuse, poisonings
Define automaticity
The characteristic of the heart to generates its own beat. The brain does not tell it when to beat, it does that on its own.
Brain can speed it up using sympathetic nervous system or slow it down using the parasympathetic nervous system via vagus nerve.
Blood pressure is a function of what.
Depends on the pumping contractility of the ventricles (reflected by the systolic pressure),
the stroke volume (which in part is a function of preload = the amount of blood returning to the heart [starlings law of the heart], ejection fraction and total body fluid volume),
the heart rate, PVR (how well the arterioles pump, reflected by the diastolic pressure)
RBC - basic function
Important in transporting O2 to cells
Contain hemoglobin to carry O2
WBC - basic function
Important in fighting infection