LEC 3

Question 1

اماكن بقدر اقيس منها كهربية الجسم

Answer 1

EEG of the brain, &electrical activity of the muscles), but the heart is the greatest electrical activity,

Question 2

Einthoven’s method

Answer 2

3 Lead
2 arm
1 left leg

Question 3

lead 1

Answer 3

Connecting the right arm with the left arm

Question 4

lead 2

Answer 4

Connecting the right arm with the left leg

Question 5

lead 3

Answer 5

Connecting the left arm with the left leg

Question 6

first 3 leads are

Answer 6

bipolar leads

Question 7

bipolar leads records

Answer 7

difference between these two points

Question 8

unipolar leads measure

Answer 8

the potential of only one point

Question 9

The maximum voltage must be within

Answer 9

lead 2, because it is parallel to the direction of the current (base to apex).

Question 10

The bipolar leads can be used to diagnose

Answer 10

different cardiac arrhythmias abnormalities in the period of times between different waves of the cycle.
(if it’s prolonged or shortened).

Question 11

Chest leads are used in diagnose

Answer 11

abnormalities in the waves themselves e.g. QRS

Question 12

V1 Place

Answer 12

fourth intercostal space to the right of the sternum

Question 13

V2 Place

Answer 13

fourth intercostal space to the left of the sternum.

Question 14

V4 Place

Answer 14

fifth intercostal space in the left midclavicular line.

just beneath the nipple.

Question 15

V3 Place

Answer 15

in between V2 and V4

Question 16

V5 Place

Answer 16

anterior axillary line within fifth intercostal space.

Question 17

V6 Place

Answer 17

middle axillary line within fifth intercostal space.

Question 18

V1 Related part in heart

Answer 18

Right ventricle

Question 19

V2 Related part in heart

Answer 19

The sputum between the ventricles.

Question 20

V3 Related part in heart

Answer 20

Anterior of the left ventricle

Question 21

V4 Related part in heart

Answer 21

Anteroseptal aspect of the left ventricle.

Question 22

V5 Related part in heart

Answer 22

Anterolateral aspect of the left ventricle

Question 23

V6 Related part in heart

Answer 23

Lateral aspect of the left ventricle

Question 24

IN chest leads The sign of current depends on

Answer 24

where we put the electrodes and the direction of the current.

Question 25

These chest leads help us in

Answer 25

myocardial infraction patients to identify which part is | affected by the infraction.

Question 26

12 leads are divided into

Answer 26

1. Bipolar leads: (also called bipolar limb lead): which includes: lead I, lead II, and lead III. 2. Unipolar leads: which are subdivided into: A. unipolar limp leads: (AVR, AVL & AVF). B. unipolar chest leads: (V1, V2, V3, V4, V5 and V6).

Question 27

what we are examining in AVF

Answer 27

the inferior part of the left ventricle.

Question 28

The first part of the ventricle that will be excited is | direction of excitation

Answer 28

the base of the septum is from the left to the right, Q wave → negative . why → to the RT and the current is to the LF and from endocardium to the epicardium (from inside to the outside).

Question 29

the second part of the the ventricle that will be excited is

Answer 29

Base of the septum → apex → lateral wall

Question 30

benefits of the the presence of Purkinje fibers

Answer 30

excitation of apex to the lateral wall develop in a very short period of time

Question 31

30 milliseconds لشو هاي

Answer 31

excitation from SA node to AV node and the time for depolarization of both of the atria)

Question 32

130 milliseconds لشو هدول

Answer 32

delay in the av node

Question 33

60ms

Answer 33

ventricles excitation

Question 34

220 milliseconds.

Answer 34

excitation to start in the SA node until the stimulation of both ventricles

Question 35

PR segment

Answer 35

from the end of p wave to the beginning of QRS)

Question 36

The PR segment is called

Answer 36

isoelectric line

Question 37

2 things happen at the same tim

Answer 37

atrial repolarization and the depolarization of ventricle

Question 38

how to see the repolarization of atria

Answer 38

put a catheter on the atria, stimulate it and see the repolarization.

Question 39

Intervals in ECG

Answer 39

1. PR interval 2) QT interval 3) TP interval

Question 40

PR interval represents

Answer 40

duration of the impulse to start in the SA node until it | reaches the ventricles (including the delay that happens in the AV node).

Question 41

PR interval كم تشتغرق من الوقت

Answer 41

160 millisecond | 120 to 200 millisecond.

Question 42

PR interval includes

Answer 42

depolarization of atria &the plateau of atria.

Question 43

the relationship between PR interval and heart rate

Answer 43

عكسية When we are sleeping: the heart rate decreases, so the PR interval will increase. When we do exercise, anxiety: the heart rate will increase, so the PR interval will be shorter.

Question 44

QT interval represents

Answer 44

the AP of the ventricles depolarization, plateau and repolarization of the ventricles

Question 45

QT interval كم تستغرق من الوقت

Answer 45

350 milliseconds

Question 46

QT interval in myocardial infarction) & angina

Answer 46

increasedbecause the wash out of ions will be abnormal {problem in the sodium potassium pump})

Question 47

TP interval time represents

Answer 47

the resting potential,

Question 48

interval that all channels is closed

Answer 48

TP interval

Question 49

interval that represents the resting potential

Answer 49

TP interval

Question 50

during TP interval

Answer 50

leakage of the Na in the SA node, not in the ventricles or atria, waiting for the threshold to be reached to the next beat. (

Question 51

isoelectric lines

Answer 51

PR segment, ST segment and TP | interval

Question 52

R wave

Answer 52

depolarization of the lateral wall of the | ventricles)

Question 53

Qwave

Answer 53

depolarization of the base of the septum

Question 54

the right side

Answer 54

S increase and R decreased

Question 55

the left side

Answer 55

R↑ | S ↓

Question 56

Small R and large S

Answer 56

in V1

Question 57

R will be at the maximum

Answer 57

V6 left side

Question 58

R Will be at the minimum

Answer 58

V1 or V2 right side

Question 59

S will be at the maximum

Answer 59

V 1or V2 right side

Question 60

S at minimum in

Answer 60

V6

Question 61

waves in AVR are

Answer 61

negative

Question 62

why is T wave positive

Answer 62

the direction of repolarization of the ventricles starts from the outside to the inside