N217 - Physiology Lab - quiz #3 - The heart

What structure is the pacemaker of the heart?

The SA node

Which electrical activity is responsible for atrial systole?

P wave

Which electrical activity is responsible for atrial diastole?

QRS complex

Which electrical activity is responsible for atrial depolarization?

P wave

Which electrical activity is responsible for atrial depolarization?

QRS complex

Which electrical activity is responsible for ventricular systole?

QRS complex

Which electrical activity is responsible for ventricular diastole?

T wave

Which electrical activity is responsible for ventricular depolarization?

QRS complex

Which electrical activity is responsible for ventricular depolarization?

T wave

Regurgitation of blood from the ventricle to the atria would be heard during _____.

Ventricular systole

Regurgitation of blood from the ventricle to the atrium would be indicative of a(n) _____.

Insufficient valve

Which of the following bipolar leads would utilize electrodes placed on the left arm and the left leg?

Lead 3

Equation for the calculation of pulse pressure

PP = systolic pressure - diastolic pressure

2 equations for the calculation of MAP

MAP = 1/3 PP + diastolic pressure
OR
MAP = (systolic pressure + 2 x diastolic pressure) / 3

What is the correct blood pressure category for a person with a blood pressure of 120/95?

Hypertensive - Stage 1

What is the correct blood pressure category for a person with a blood pressure of 115/85?

Prehypertensive

What is the correct blood pressure category for a person with a blood pressure of 165/95?

Hypertensive - Stage 2

What is the correct blood pressure category for a person with a blood pressure of 110/70?

Normal

When a person is exercising (compared to when they are at rest), what change would you expect to see in the pulse rate?

Increase

When a person is exercising (compared to when they are at rest), what change would you expect to see in the R wave - pulse interval?

Decrease

When a person is exercising (compared to when they are at rest), what change would you expect to see in the P-R interval?

Decrease

When a person is exercising (compared to when they are at rest), what change would you expect to see in the Pulse wave amplitude?

Increase

When a person is exercising (compared to when they are at rest), what change would you expect to see in the time spent in ventricular systole?

Decrease

When a person is exercising (compared to when they are at rest), what change would you expect to see in the PERCENTAGE of time spent in ventricular systole?

Increase

When a person is exercising (compared to when they are at rest), what change would you expect to see in the systolic pressure?

Increase

When a person is exercising (compared to when they are at rest), what change would you expect to see in the MAP?

Increase

Define systolic blood pressure

The force of the blood against the walls of arteries as a result of ventricular systole.

Define diastolic blood pressure

The force of blood against the walls of arteries as a result of ventricular diastole.

Define pulse pressure

The difference between systolic BP and diastolic BP

You blood pressure is measured as ____ / ____.

systolic/diastolic

Define MAP (Mean Arterial Pressure)

The average pressure the arteries are exposed to during a single cardiac cycle.

MAP is a measure of _____.

hemodynamic perfusion pressure (how well blood is reaching individual organs).

Blood in vessels has a ____ flow.

laminar (smooth, undisrupted flow in concentric layers; makes no noise)

The indirect auscultatory method of blood pressure measurement is taken using a _____.

Sphygmomanometer (blood pressure cuff)

The first sound of Korotkoff:

Some blood flow returns at the point of systolic pressure; heard as a thumping sound (first thump)

The second sound of Korotkoff:

Last sound heard as laminar flow returns

Isoelectric line

No electrical activity is being generated by the heart.

P Wave

represents atrial depolarization; result of the activation of the SA node

QRS Complex

represents ventricular depolarization; result of the activation of the AV node

T Wave

represents ventricular depolarization

U Wave

small positive wave; final remnants of ventricular depolarization; sometimes seen after the T wave

R Wave

Peak of QRS complex (measures ECG)

S Wave

Negative deflection following the R wave

Q Wave

first downward wave of QRS complex (often absent)

P-R interval

-beginning of P wave to beginning of QRS complex
-interval between activation of SA node and activation of AV node
-used to assess the conduction of electrical activity to the ventricles

P-R segment

-end of P wave to beginning of QRS complex
-interval between atrial depolarization and ventricular depolarization

S-T segment

-end of S wave to beginning of T wave
-should be at isoelectric line b/c ventricles are uniformly excited

Q-T interval

-beginning of QRS complex to end of T wave
-period of time it takes for ventricles to depolarize and repolarize

During REST, how much of a cardiac cycle are the ventricles expected to be in systole?

40% of the cycle

During EXERCISE, how much of a cardiac cycle are the ventricles expected to be in systole?

65% of the cycle

The 2 AV valves

Tricuspid valve and Bicuspid (Mitral) valve

The 2 Semilunar valves

Pulmonary valve and Aortic valve

Insufficient valve

regurgitation/backflow of blood; OR a valve does not close completely

Stenotic valve

valve opening is reduced in size so that blood flow is restricted

Electrical activity pathway!!!!!

SA node --> AV node --> Bundle of His --> Right and Left bundle Branches --> Purkinje fibers
SA; AV; BofH; BB; PF

SA node

Sinoatrial node

AV node

Atrioventricular node

KNOW THE CARDIAC CYCLE!!!!

1) SA node generates an action potential
2) Spreads through atria, resulting in atrial depolarization - P Wave (.08-.1 sec)
3) Stimulation results in atrial systole (contraction) and stimulation of the AV node
4) Action potential from AV node conducted th

Pulse channel

Rate of change of blood pressure entering the fingertip of the subject

The flow of blood is ____ than the transmission of a pressure wave through the arteries.

slower

Pulse deficit

When the peripheral pulse is lower than the apical pulse

Peripheral pulse

correct term for a pulse that is counted in the peripheral arteries of a person

Apical pulse

number of ventricular contractions counted

Systolic murmur

-Valve that should be closed during systole but allows some backflow of blood
OR
-Valve that should be open during systole but has a reduced opening

Diastolic murmur

-Valve that should be closed during diastole but allows some backflow of blood
OR
-Valve that should be open during diastole but has a reduced opening

Which heart sounds are associated with unidirectional flow?

S1 and S2 (lub - dub)

S1

-lub
-closing of AV valves
-Heard shortly after beginning of ventricular systole
-Result of the electrical activity of the QRS complex

S2

-dub
-closing of the semilunar valves
-Heard shortly after the beginning of ventricular diastole
-Result of the electrical activity of the R wave

S3

-passive blood flow from atria into ventricles immediately after the AV valves open during atrial and ventricular diastole
-Following S2 but prior to the P wave

S4

-due to atrial systole and final filling of the ventricles
-Results from the P wave

Which of the four heart sounds is the loudest?

S1

Are AV valves or semilunar valves larger?

AV valves

Why are AV valves larger than semilunar valves??

b/c they snap shut with more force due to the high pressure developed because of ventricular systole

R-S1

-Time between ventricular depolarization (R) and closing of the AV valves
-Mechanical event is beginning of ventricular systole

T-S2

-Time between ventricular repolarization (T) and closing of the semilunar valves
-Mechanical event is the beginning of ventricular diastole

S1-S2

-Time between closing of the AV valves and closing of the semilunar valves
-Completion of ventricular systole and beginning of ventricular diastole
-Blood is ejected from the ventricles

S2-S1

-Time between closing of the semilunar valves and closing of the AV valves
-Completion of ventricular diastole and atrial systole, followed by ventricular systole and atrial diastole
-Passive filling and final filling of the ventricles occurs during this