Chapter 12 : the heart

Question 1

Name the 2 atrioventricular valves

Answer 1

Tricuspid Valve

Bicuspid (Mitral)

Question 2

Name the 2 semilunar valves

Answer 2

Pulmonary valve

aortic valve

Question 3

Atrioventricular valves do what in high pressure?

Answer 3

Shut/close in high pressure

Question 4

Semilunar valves do what in high pressure

Answer 4

open in high pressure

Question 5

What is systole

Answer 5

when the ventricles are CONTRACTING and blood goes into the arteries
- blood pushing out of the heart

Question 6

What is Diastole

Answer 6

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

Question 7

What is S1

Answer 7

First heart sound
- sound made by atrioventricular valves slamming shut.
Starts systole

Question 8

What is S2

Answer 8

Second heart sound

• made by semilunar valves slamming shut.
• starts diastole

Question 9

Cardiac output equation

Answer 9

Heart rate x stroke volume

ex: 60 bpm x 80 mL/beat=?

Question 10

what is the Cardiac output for a normal average person?

Answer 10

75 bpm x 80 mL/beat=6000 mL/min

= 6 Liters/min

Question 11

which ventricle of the heart has a thick muscle wall and why?

Answer 11

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

Question 12

what is first degree heart block

Answer 12

everything from the signal is getting through, but slowly.
no symptoms

• PR interval is too long

Question 13

What is 2nd degree heart block

Answer 13

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

Question 14

what is 3rd degree heart block

Answer 14

NOTHING GETS THROUGH.
the atria and the ventricles have their own pacemakers. This occurs when each pace maker is doing something totally different

Question 15

conducting system of the heart steps

Answer 15

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.

Question 16

How does the ANS effect the heart

Answer 16

Anything that activates the ANS can affect cardiac input.

• Norepiniephrine and epinephrine INCREASE hr in SA node
• Acetylcholine DECREASES hr in SA node

Question 17

what is myocardial infarction

Answer 17

heart attack

- destroys parts of the conducting pathway

Question 18

what causes heart block

Answer 18

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

Question 19

What is the EKG?

name the three major waves

Answer 19

the ELECTROCARDIOGRAM that measures the heart’s electicity. What you see on a heart monitor

• P Wave
• QRS complex
• T wave

Question 20

where is the P wave and what does it represent?

Answer 20

• First small bump on the graph

- measures the DEPOARIZATION of the ATRIA (SA node to AV node)

Question 21

Where is the QRS complex and what does it represent?

Answer 21

• the big spike on the graph

- measures the DEPOLARIZATION of the VENTICLES

Question 22

Where is the T wave and what does it represent?

Answer 22

• Last small bump

- measures the REPOLARIZATION of the VENTRICLES

Question 23

What is Bradycardia

Answer 23

Really slow heart rate

• less than 60 BPM
• some athletes can go below this and be fine

Question 24

What is Tachycardia

Answer 24

Really fast heart rate

• more than 100 bpm at rest
• can achieve this during exercise and be fine

Question 25

what is cardiac arrhythmia

Answer 25

irregular heart beat rhythm

Question 26

Atrial fibirllation

Answer 26

NOT rhythmic not predictable

- rate and the rhythm keep changing

Question 27

Atrial flutter

Answer 27

• regularly irregular and predictable

- the rhythm is wrong but the rate is regular

Question 28

what is a cardiac murmmer

Answer 28

rumbling sounds caused by turbulent blood

Question 29

what is valvular stenosis:

Answer 29

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

Question 30

what is valvular insufficiencies

Answer 30

Cuases heart murmur

- when blood BACKWASHES because the valve isn’t doing its job of holding it back.

Question 31

What is interventricular septal defects

Answer 31

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

Question 32

What is severe anemia

Answer 32

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.