Cardiovascular System

Question 1

Duration of PR interval of ECG (HR: 75/min)

Answer 1

0.2 s

Question 2

Duration of P wave of ECG (HR: 75/min)

Answer 2

0.1 s

Question 3

Duration of QRS complex of ECG (HR: 75/min)

Answer 3

0.1 s

Question 4

Duration of QT interval

Answer 4

0.4 sec

Question 5

Amplitude of ST-segment of ECG (isoelectric)

Answer 5

+/- 0.1 mV

Question 6

Amplitude of R and T waves of ECG in II. lead

Answer 6

• R wave: 1.5 mV
• T wave: 0.5 mV

Question 7

RR interval

Answer 7

0.8 s

Question 8

Duration of cardiac cycle (HR: 75/min)

Answer 8

0.8 s

Question 9

Duration of systole (HR: 75/min)

Answer 9

0.27 s

Question 10

Duration of diastole (HR: 75/min)

Answer 10

0.53 s

Question 11

Duration of ventricular ejection (HR: 75/min)

Answer 11

0.25 s

Question 12

Duration of ventricular filling (HR: 75/min)

Answer 12

0.3 s

Question 13

Stroke volume

Answer 13

70 ml

End-diastolic volume: 140 ml

End-systolic volume: 70 ml

Question 14

Systolic pressure in the aorta

Answer 14

120 mmHg

Question 15

Diastolic pressure in the aorta

Answer 15

80 mmHg

Question 16

Right ventricular pressure

Answer 16

• Systole: 25 mmHg
• Diastole: 5 mmHg

Question 17

Left ventricular pressure

Answer 17

• Systole: 120 mmHg
• Diastole: 10 mmHg (less that 10!)

Question 18

Pulmonary artery pressure

Answer 18

• Systole: 25 mmHg
• Diastole: 8 mmHg

Question 19

Central venous pressure (CVP)

Answer 19

5 mmHg

Question 20

Mean blood pressure in pulmonary circulation

Answer 20

14 mmHg

Question 21

Blood pressure in left atrium

Answer 21

8 mmHg

Question 22

Driving blood pressure in pulmonary circulation

Answer 22

14-8 = 6 mmHg

Question 23

Kidney

Answer 23

Blood flow:

• 25% (of CO) rest
• 4% exercise

AVDO2: 15 mlO₂/L (350ml/100g/min)

Question 24

Splanchnic area

Answer 24

Blood flow:

• 25% rest
• 5% exercise

AVDO2: 35 mlO₂/L

Question 25

Brain

Answer 25

Blood flow: * 15% rest * 4% exercise AVDO2 in the brain: 60 mlO₂/L

Question 26

Heart

Answer 26

Blood flow: * 5% rest (250 ml/min) * 5% exercise AVDO2 (oxygen extraction): * Resting condition: 120 mlO₂/L * Physical exercise: 500 mlO₂/L (not sure) O₂ consumption: * 30 mlO₂/min resting (whole body 250 mlO₂/min)

Question 27

Skin

Answer 27

Blood flow: * 5% rest * 10% exercise (not sure) AVDO2: 20-30 mlO₂/L

Question 28

Skeletal muscle

Answer 28

Blood flow: * 25% rest * 75% exercise (not sure) AVDO2: * Resting: 60 mlO₂/L * Physical exercise: 150 mlO₂/L

Question 29

Oxygen consumption in 1 minute

Answer 29

250 ml/min

Question 30

AVDO2 in the systemic circulation

Answer 30

50 mlO₂/L

Question 31

Cerebrospinal fluid (CSF) volume

Answer 31

150 ml

Question 32

Protein concentration of cerebrospinal fluid

Answer 32

15-45 mg/dL

Question 33

Hydrostatic pressure of interstitial fluid

Answer 33

-2 mmHg

Question 34

Hydrostatic pressure of capillaries

Answer 34

* Arteriolar end: +36 mmHg * Venular end: +16 mmHg

Question 35

Effective filtration pressure of capillaries

Answer 35

* Arteriolar end: +12 mmHg * Venular end: -4 mmHg

Question 36

Rate of lymph production

Answer 36

120 ml/hour

Question 37

Hematocrit (Ht or HCT)

Answer 37

Normal value: 37-50%

Question 38

Ejection fraction

Answer 38

55%

Question 39

Cardiac output (CO)

Answer 39

5000 ml/min

Question 40

Normal sinus rhythm

Answer 40

60-100 impulses per minute

Question 41

Atrial, ventricular and Purkinje fibers action potential

Answer 41

From -85 mV to +20 mv

Question 42

SA node action potential

Answer 42

From -65 mV (maximum diastolic potential) to about +10 mV

Question 43

Chronotropic effects

Answer 43

The effects of the autonomic nervous system on _heart rate_ are called chronotropic effects.

Question 44

Dromotropic effects

Answer 44

The effects of the autonomic nervous system on _conduction velocity_ are called dromotropic effects.

Question 45

Ionotropic effect

Answer 45

* Agents that produce an increase in _contractility_ are said to have positive inotropic effects. Positive inotropic agents increase both the rate of tension development and the peak tension. * Agents that produce a decrease in contractility are said to have negative inotropic effects. Negative inotropic agents decrease both the rate of tension development and the peak tension.