The Cardiovascular System

Question 1

The right side of the heart receives oxygen ..?.. blood from body ..?.. and then pumps this blood to the ..?.. to pick up ..?.. and dispel ..?… The blood vessels that carry blood to and from the lungs form the ..?..

Answer 1

Poor; tissues; lungs; oxygen; carbon dioxide; pulmonary circuit

Question 2

The left side of the heart receives the ..?.. blood returning from the ..?.. and pumps this blood throughout the body to supply ..?.. and ..?.. to body ..?… The blood vessels that carry blood to and from all body tissues form the ..?..

Answer 2

Oxygenated; lungs; oxygen; nutrients; tissues; systemic circuit

Question 3

Describe the coordinated electrical activity of the heart

• The ability of cardiac muscle to ..?.. and ..?.. is ..?..: it’s a property of the ..?.. muscle and does not depend on the ..?.. system

Answer 3

Depolarise; contract; intrinsic; heart; nervous

Question 4

What is the path from the SA node to the end of repolarisation in terms of electrical activity of the heart?

Answer 4

1. Sinoatrial node
2. Atrioventricular node
3. Atrioventricular bundle (bundle of His)
4. Right and left bundle branches
5. Sub endocardial conducting network (Purkinje fibres)

Question 5

What is the total time between initiation of an impulse by the SA node and depolarisation of the last of the ventricular muscle cells?

Answer 5

0.22s

Question 6

Sinoatrial node
o Located in ..?.. inferior to the ..?..
o Generates ..?.. as the hearts ..?.. in a ..?.. rhythm
o Fastest ..?.. rate of the ..?.. conducting system
o Depolarisation wave spreads via ..?.. through the ..?.. and via the ..?.. pathway to the ..?.. node

Answer 6

• RA wall; SVC
• impulses; pacemaker; sinus rhythm
• depolarising; intrinsic
• gap junctions; atria; internodal; AV

Question 7

Atrioventricular node

o Located in ..?.. part of the ..?.. septum immediately above the ..?.. valve
o ..?.. the impulses from the ..?.. node by ..?.. to allow the ..?.. to respond and complete their ..?.. due to the smaller ..?.. of the fibres here and because of fewer ..?..
o Therefore, AV node conducts impulses ..?.. than rest of ..?.. system
o Also protects the ..?.. from excessively ..?.. rate response to ..?.. by ..?.. conduction, in which the more ..?.. the node is ..?.. the ..?.. it conducts

Answer 7

• inferior; interatrial; tricuspid
• delays; SA; 0.1s; atria; contraction; diameter; gap junctions
• slower; conducting
• ventricles; fast; atrial arrythythmias; decremental; frequently; stimulated; slower

Question 8

Atrioventricular bundle (bundle of His)

o Located in the ..?.. part of the ..?.. septum
o This is the only ..?.. connection between the ..?.. and ..?.. (no ..?.. between them)
o The fibrous ..?.. skeleton ..?.. the rest of the ..?…

Answer 8

• superior; interventricular
• electrical; atria; ventricles; gap junctions
• cardiac; insulins; AV junction

Question 9

Right and left bundle brunches

o Course along the ..?.. toward the heart ..?..
o Excites the ..?.. cells

Answer 9

• interventricular septum; apex
• septal

Question 10

Subendocardial conducting network (Purkinje fibres)

o Penetrates the heart ..?.. and spread through the ..?..
o Excites the ..?.. with ..?.. via ..?.. in the ..?.. cells
o Network is more elaborate on the ..?.. due to the ..?.. size of this ..?..
o Contraction begins at the heart ..?.. and moves toward the ..?..

Answer 10

• apex; ventricle walls
• ventricles; transmission; gap junctions; cardiac
• left; larger; ventricle
• apex; atria

Question 11

Sequence of intrinsic conduction system (sequence of electrical excitation)

1. The ..?.. node (..?..) generates ..?..
2. The impulses pause (..?..s) at the ..?.. node
3. The ..?.. bundle connects the ..?.. to the ..?..
4. The ..?.. branches conduct the ..?.. through the ..?.. septum
5. The ..?.. conducting network ..?.. the ..?.. cells of both ..?..

Answer 11

1. Sinoatrial; pacemaker; impulses
2. 0.1; atrioventricular
3. Atrioventricular; atria; ventricles
4. Bundle; impulses; interventricular
5. Subendocardial; depolarises; contractile; ventricles

Question 12

Pacemaker potential (..?..):

..?.. changing ..?.. potentials that initiate ..?.. that spread throughout the ..?.. to trigger rhythmic ..?… Due to special properties of the ..?.. channels in the ..?..

Answer 12

Prepotentials

Spontaneously; membrane; APs; heart; contractions; ion; sarcolemma

Question 13

Cardiac pacemaker cells (..?.. cells): ..?.. cardiac cells that stimulates the ..?.. muscle, regulating its ..?.. and directly determining ..?..

• Pacemaker cells have ..?.. resting potential that continually ..?.., drifting slowly toward ..?..
• In these cells, ..?.. both closes ..?.. channels and opens slow ..?.. channels
• ..?.. influx causes membrane ..?.. to become more ..?..
• At threshold, ..?.. channels ..?.. allowing a massive ..?.. of ..?..
• It is this Ca2+ ..?.. (rather than ..?..) that produces a ..?.. phase of the ..?.. and ..?.. the membrane potential
• ..?.. occurs as ..?.. with opening of ..?.. channels

Answer 13

Autorhythmic; non-contractile; heart; contractions; heart rate

• unstable; depolarises; threshold
• hyperpolarisation; K+; Na+
• Na+; interior; positive
• Ca2+; open; influx; Ca2+
• influx; Na+; rising; AP; reverses
• repolarisation; normal; K+

Question 14

Define spontaneous depolarization of cardiac tissue and list the ionic currents responsible for this elctrical activity of the heart

• Ultimately at ..?.. Ca2+ channels ..?.. allowing explosive entry of ..?.. from the ..?.. space.
• In ..?.. cells it is the influx of ..?.. (rather than ..?..) that produces the ..?.. phase of the ..?.. and ..?.. the membrane potential

Answer 14

• threshold; open; Ca2+; extracellular
• pacemaker; Ca2+; Na+; riding; AP; reverses

Question 15

Describe the role of the AV node in transmitting and filtering impulses

• From the ..?.. node, the ..?.. wave spreads via ..?.. throughout the ..?.. and via the ..?.. pathway to the ..?.. node, located in the ..?.. portion of the ..?.. septum immediately above the ..?.. valve.
• At the ..?.. node, the impulse is ..?.. for about ..?.., allowing the ..?.. to respond and complete their ..?.. before the ..?.. contract. This delay reflects the smaller ..?.. of the fibres here and the fact that they have fewer ..?.. for ..?.. flow.
• Consequently, the ..?.. node conducts ..?.. more ..?.. than other parts of the ..?.., just as traffic slows when cars are forced to merge from four lanes into two.
• Once through the ..?.. node, the ..?.. impulse passes rapidly through the ..?.. of the system

Answer 15

• SA; depolarisation; gap junctions; atria; inter-nodal; atrioventricular; inferior; inter-atrial; tricuspid
• AV; delayed; 0.1s; atria; contraction; ventricles; diameter; gap junctions; current
• AV; impulses; slowly; system
• AV; signalling; rest

Question 16

What is the depolarisation rate in beats per minutes of the SA node?

Answer 16

75 beats/ minute

Question 17

What is the depolarisation rate in beats per minutes of the AV node?

Answer 17

50 beats/ minute

Question 18

What is the depolarisation rate in beats per minutes of the AV bundle and Purkinje fibres?

Answer 18

30 beats/ minute

Question 19

AP of cardiac cells

1. ..?.. potential. This slow ..?.. is due to both opening of ..?.. channels and closing of ..?.. channels. Note: the membrane potential is never a ..?.. line
2. Depolarisation- the AP begins when the ..?.. potential reaches ..?… Depolarisation is due to ..?.. influx through ..?.. channels
3. Repolarisation is due to ..?.. channels ..?.. and ..?.. channels ..?… This allows ..?.. efflux, which brings the membrane potential back to its most ..?.. voltage

Answer 19

1. Pacemaker; depolarisation; Na+; K+; flat
2. Pacemaker; threshold; Ca2+; Ca2+
3. Ca2+; inactivating; K+; opening; K+; negative

Question 20

• Systole: the phase of the heartbeat when the heart muscle ..?.. and pumps blood from the ..?.. into the ..?..
• Diastole: the phase of the heartbeat when the heart muscle ..?.. and allows the ..?.. to ..?.. with blood.

Answer 20

• contracts; chambers; arteries
• relaxes; chambers; fill

Question 21

What are the stages involved in the cardiac cycle?

Answer 21

1. Ventricle filling: mid-late diastole
2. Ventricle systole
3. Isovolumetric relaxation: early diastole

Question 22

How long is each cardiac cycle?

Answer 22

0.8s

Question 23

1. Ventricle filling: mid-late diastole of the cardiac cycle

o Pressure in the heart is ..?.., blood ..?.. from circulation flows ..?.. through the ..?.. and open ..?.. values into the ..?..
o ..?.. and ..?.. valves are ..?..
o ..?.. of ..?.. filling occurs now
o ..?.. wave of ECG
o ..?.. contract
§ Sudden light ..?.. in ..?.. pressure propelling blood into ..?..
§ Ventricles in last part of diastole and are ..?.. filled (..?.., EDV)
o Atria ..?.. and ventricles ..?.. (..?.. complex)
o Atrial ..?.. persists for ..?.. of the cycle

Answer 23

o low; returning; passively; atria; AV; ventricles
o aortic; pulmonary; closed
o 80%; ventricle
o P
o atria
§ rise; atrial; ventricles
§ maximally; end diastole volume
o relax; depolarise; QRS
o diastole; rest

Question 24

2. Ventricle-systole of the cardiac cycle

o Contraction causes sharp ..?.. in ..?.. pressure and ..?.. of ..?.. valves
o ..?.. contraction phase is when ..?.. are completely ..?.. and volume remains ..?..
o ..?.. pressure continues to ..?.. until ..?.. pressure in ..?..
o ..?.. phase ends as the ..?.. valves are forced ..?.. and blood rushes into the ..?.. and ..?..
o Pressure in the ..?.. normally reaches ..?..
o Meanwhile ..?.. are ..?.. with blood and ..?.. pressure ..?..

Answer 24

o rise; ventricle; closure; AV
o isovolumetric; ventricles; closed; constant
o ventricular; rise; exceeds; large arteries
o isovolumetric; SL; open; aorta; pulmonary trunk
o aorta; 120mmHg
o atria; filling; intra-atrial; rises

Question 25

3. Isovolumetric relaxation: early diastole of the cardiac cycle

o Ventricles ..?.. during brief phase following ..?.. wave
o ..?.. (ESV) is the blood ..?.. in the ..?..
o Ventricle pressure ..?.. rapidly, and blood in the ..?.. and ..?.. flows back ..?.. the heart ..?.. the ..?.. valves
o Closure of the ..?.. valve ..?.. aortic pressure briefly as ..?.. flowing blood rebounds off the ..?.., shown in the pressure graph as the ..?..
o Again the ..?.. are completely ..?..
o When BP on the ..?.. side of the ..?.. valves exceeds that in the ..?.., the AV valves are forced ..?.. and ventricle ..?.. begins
o ..?.. pressure is at its ..?.. and ventricle pressure ..?.., starting the ..?.. again

Answer 25

o relax; T
o end systolic volume; remaining; ventricles
o drops; aorta; pulmonary trunk; towards; closing; SL
o aortic; increases; back; valve cusps; dicrotic notch
o ventricles; closed
o atrial; AV; ventricles; open; filling
o atrial; minimum; rises; cycle

Question 26

How long is atrial systole?

Answer 26

0.1s

Question 27

How long is ventricle systole?

Answer 27

0.3s

Question 28

How long is total heart relaxation (quiescent period)?

Answer 28

0.4s

Question 29

First heart sound is ..?.. valves ../..

o Beginning of ..?..
o ..?.. pressure is ..?.. than ..?.. pressure
o ..?.. valve ..?.. slightly ..?.. the ..?.. valve
o This sound is ..?.., more ..?..

Answer 29

AV; closing

o ventricle systole
o ventricle; greater; atrial
o mitral; closes; before; tricuspid
o louder; resonant

Question 30

Second heart sound is the SL valves closing

o Beginning of ..?..
o ..?.. valve ..?.. slightly ..?.. the ..?.. valve
o Short, ..?.. sound

Answer 30

SL; closing

o ventricle diastole
o aortic; closes; before; pulmonary
o sharp

Question 31

• aortic valve sounds heard in the ..?.. space at the ..?.. margin
• pulmonary valve sounds beards in the ..?.. space at the ..?.. margin
• mitral valve sounds heart over ..?.. (in ..?.. space) in line with the middle of the ..?..
• tricuspid valve sounds typically heard in the ..?.. margin of the ..?.. space

Answer 31

• 2nd intercostal; right sternal
• 2nd intercostal; left sternal
• heart apex; 5th intercostal; clavicle
• right sternal; 5th intercostal

Question 32

• ECG: A composite of all ..?.. generated by ..?.. and ..?.. cells at a given ..?.. (not a ..?.. action potential)
• Device: ..?..
• Graphic record: ..?.. (ECG)

Answer 32

• APs; nodal; contractile; time; single
• electrocardiograph
• electrocardiogram