Chapter 12 : the heart Flashcards
Name the 2 atrioventricular valves
Tricuspid Valve
Bicuspid (Mitral)
Name the 2 semilunar valves
Pulmonary valve
aortic valve
Atrioventricular valves do what in high pressure?
Shut/close in high pressure
Semilunar valves do what in high pressure
open in high pressure
What is systole
when the ventricles are CONTRACTING and blood goes into the arteries
- blood pushing out of the heart
What is Diastole
when the ventricals are RELAXED, allowing blood allowing blood from the venous circulation and atria to fill the ventricles.
- lasts twice as long as a systole
What is S1
First heart sound
- sound made by atrioventricular valves slamming shut.
Starts systole
What is S2
Second heart sound
- made by semilunar valves slamming shut.
- starts diastole
Cardiac output equation
Heart rate x stroke volume
ex: 60 bpm x 80 mL/beat=?
what is the Cardiac output for a normal average person?
75 bpm x 80 mL/beat=6000 mL/min
= 6 Liters/min
which ventricle of the heart has a thick muscle wall and why?
The left has a much thicker wall because the right side only has to deliver blood to the lungs while the left side has to deliver blood to the rest of the body.
- The left ventricle has to pump at a much higher pressure
what is first degree heart block
everything from the signal is getting through, but slowly.
no symptoms
- PR interval is too long
What is 2nd degree heart block
1- sometimes signals get through and to the heart sometimes they don’t
- pacemaker is driving one side of the heart faster than the other and the signal gets stopped because the muscle is in refractory phase
what is 3rd degree heart block
NOTHING GETS THROUGH.
the atria and the ventricles have their own pacemakers. This occurs when each pace maker is doing something totally different
conducting system of the heart steps
1- The signal starts in the sinoatrial (SA) node near the venous entry to the right atrium, which is full of nodal cells which establish the rate of contraction.
2- Conducting cells take the signal from the SA node around the atrium to the atrioventricular (AV) node, where there are more nodal cells which carry the signal to the ventricles. This is a stop point, so that the atria contract before the ventricles do.
3- From the AV node, the signal goes down the AV bundle in the interventricular septum,
4- then branches into Purkinje fibers (At the apex) that carry the contractile signal to the ventricular myocardium.
How does the ANS effect the heart
Anything that activates the ANS can affect cardiac input.
- Norepiniephrine and epinephrine INCREASE hr in SA node
- Acetylcholine DECREASES hr in SA node
what is myocardial infarction
heart attack
- destroys parts of the conducting pathway
what causes heart block
atria and ventricles aren’t beating together because
- nodal cells are working when they shouldn’t
- electricity is being blocked going through the heart the normal way
What is the EKG?
name the three major waves
the ELECTROCARDIOGRAM that measures the heart’s electicity. What you see on a heart monitor
- P Wave
- QRS complex
- T wave
where is the P wave and what does it represent?
- First small bump on the graph
- measures the DEPOARIZATION of the ATRIA (SA node to AV node)
Where is the QRS complex and what does it represent?
- the big spike on the graph
- measures the DEPOLARIZATION of the VENTICLES
Where is the T wave and what does it represent?
- Last small bump
- measures the REPOLARIZATION of the VENTRICLES
What is Bradycardia
Really slow heart rate
- less than 60 BPM
- some athletes can go below this and be fine
What is Tachycardia
Really fast heart rate
- more than 100 bpm at rest
- can achieve this during exercise and be fine
what is cardiac arrhythmia
irregular heart beat rhythm
Atrial fibirllation
NOT rhythmic not predictable
- rate and the rhythm keep changing
Atrial flutter
- regularly irregular and predictable
- the rhythm is wrong but the rate is regular
what is a cardiac murmmer
rumbling sounds caused by turbulent blood
what is valvular stenosis:
causes heart murmur
- means NARROW opening
- blood gets turbulent when heart forces it through a narrow opening
- usually one of the 4 valves is too narrow
what is valvular insufficiencies
Cuases heart murmur
- when blood BACKWASHES because the valve isn’t doing its job of holding it back.
What is interventricular septal defects
There is a HOLE in the septum between the right and left atria or the left and right ventricles
- this causes the chambers to be at different pressures and blood is constantly flowing the wrong way
What is severe anemia
erythrocytes help keep blood flowing smoothly. Not enough of them, and you can hear blood moving so fast it sloshes in the coronary arteries that feed the heart.
