Revision Notes

Question 1

Body Fluids And Circulation

Question 2

SAN

Question 3

wpukinge fibres

Question 4

A bundle ß nodal fibres

Answer 4

AV bundle /Bundle of

Question 5

Passes thovģh the Atio -Ventriculav septum to emeve on the top af the

Question 6

Intex-Ventricvlav s<tve

Answer 6

and mmediotely divides into minute fibres thouéhovt the

Question 7

Ventviclar muscvlatwe of the both sides cloa ‘Purkinje’fibres

Question 8

The nodal muscv latuve has the ability to qehevate action potetials without ony

Question 9

ext. stimuli

Answer 9

ie.

Question 10

i is avtoexcitable. Howevev

Answer 10

te humbev of achion boTevrtials thát (oud be

Question 11

amated In a minute Vany at ditf. þavts of the ho dal system.

Question 12

max.no- o% achoh potentials

Question 13

9can generote^ 70-75 /min

Question 14

SA

Question 15

node

Question 16

9 ovr heat normally beats 70-7s times in a min (avg.2 beats/min)

Question 17

also Vesponsible fov initiating 3 main tainný Yhythmic contractile activity of the

Question 18

heavt. * is called the “pAcEMAKER.

Question 19

CARDIAC YCLE

Question 20

HAction

Question 21

potential.

Question 22

bartoy syiens

Question 23

closed.

Question 24

opeh.

Question 25

Bundle

Question 26

Of

Question 27

'HIS

Question 28

th branchs qe

Question 29

to mite tiby thss

Question 30

>Rrkinje

Question 31

fibres.

Question 32

the Ventioulav

Question 33

mmjuntwe ogthe

Question 34

t/noxation

Question 35

phase.

Question 36

bIASTOLt

Question 37

Purkinje-fibres

Question 38

| syS TOLE

Question 39

Contvaction /Nơt at est

Question 40

NOW

Answer 40

30 of blood wil qgoto

Question 41

ito the Ventricles

Question 42

Bovd -flow ↑

Question 43

I vetvicdes by

Question 44

What are Purkinje fibres?

Answer 44

Purkinje fibres are minute fibres that spread throughout the ventricular musculature of both sides of the heart.

Question 45

What is the function of the Bundle of His?

Answer 45

The Bundle of His, or AV bundle, continues from the AV node and passes through the atrioventricular septum.

Question 46

What is the role of the SA node?

Answer 46

The SA node is responsible for initiating rhythmic contractile activity of the heart and is known as the 'pacemaker'.

Question 47

What is the average heart rate initiated by the SA node?

Answer 47

The SA node normally beats 70-75 times per minute.

Question 48

What is autoexcitability in nodal musculature?

Answer 48

Nodal musculature has the ability to generate action potentials without external stimuli; it is autoexcitable.

Question 49

What is the maximum number of action potentials that can be generated in a minute?

Answer 49

The maximum number of action potentials that can be generated varies at different parts of the nodal system, with a maximum of 70-75 per minute.

Question 50

What happens during the contraction phase of the cardiac cycle?

Answer 50

During the contraction phase, about 30% of blood will go into the ventricles.

Question 51

What occurs during the diastole phase?

Answer 51

During diastole, blood flow increases into the ventricles.