The Cardiovascular System Flashcards
(32 cards)
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 ..?..
Poor; tissues; lungs; oxygen; carbon dioxide; pulmonary circuit
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 ..?..
Oxygenated; lungs; oxygen; nutrients; tissues; systemic circuit
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
Depolarise; contract; intrinsic; heart; nervous
What is the path from the SA node to the end of repolarisation in terms of electrical activity of the heart?
- Sinoatrial node
- Atrioventricular node
- Atrioventricular bundle (bundle of His)
- Right and left bundle branches
- Sub endocardial conducting network (Purkinje fibres)
What is the total time between initiation of an impulse by the SA node and depolarisation of the last of the ventricular muscle cells?
0.22s
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
- RA wall; SVC
- impulses; pacemaker; sinus rhythm
- depolarising; intrinsic
- gap junctions; atria; internodal; AV
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
- inferior; interatrial; tricuspid
- delays; SA; 0.1s; atria; contraction; diameter; gap junctions
- slower; conducting
- ventricles; fast; atrial arrythythmias; decremental; frequently; stimulated; slower
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 ..?…
- superior; interventricular
- electrical; atria; ventricles; gap junctions
- cardiac; insulins; AV junction
Right and left bundle brunches
o Course along the ..?.. toward the heart ..?..
o Excites the ..?.. cells
- interventricular septum; apex
- septal
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 ..?..
- apex; ventricle walls
- ventricles; transmission; gap junctions; cardiac
- left; larger; ventricle
- apex; atria
Sequence of intrinsic conduction system (sequence of electrical excitation)
- The ..?.. node (..?..) generates ..?..
- The impulses pause (..?..s) at the ..?.. node
- The ..?.. bundle connects the ..?.. to the ..?..
- The ..?.. branches conduct the ..?.. through the ..?.. septum
- The ..?.. conducting network ..?.. the ..?.. cells of both ..?..
- Sinoatrial; pacemaker; impulses
- 0.1; atrioventricular
- Atrioventricular; atria; ventricles
- Bundle; impulses; interventricular
- Subendocardial; depolarises; contractile; ventricles
Pacemaker potential (..?..):
..?.. changing ..?.. potentials that initiate ..?.. that spread throughout the ..?.. to trigger rhythmic ..?… Due to special properties of the ..?.. channels in the ..?..
Prepotentials
Spontaneously; membrane; APs; heart; contractions; ion; sarcolemma
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
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+
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
- threshold; open; Ca2+; extracellular
- pacemaker; Ca2+; Na+; riding; AP; reverses
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
- 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
What is the depolarisation rate in beats per minutes of the SA node?
75 beats/ minute
What is the depolarisation rate in beats per minutes of the AV node?
50 beats/ minute
What is the depolarisation rate in beats per minutes of the AV bundle and Purkinje fibres?
30 beats/ minute
AP of cardiac cells
- ..?.. potential. This slow ..?.. is due to both opening of ..?.. channels and closing of ..?.. channels. Note: the membrane potential is never a ..?.. line
- Depolarisation- the AP begins when the ..?.. potential reaches ..?… Depolarisation is due to ..?.. influx through ..?.. channels
- Repolarisation is due to ..?.. channels ..?.. and ..?.. channels ..?… This allows ..?.. efflux, which brings the membrane potential back to its most ..?.. voltage
- Pacemaker; depolarisation; Na+; K+; flat
- Pacemaker; threshold; Ca2+; Ca2+
- Ca2+; inactivating; K+; opening; K+; negative
- 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.
- contracts; chambers; arteries
- relaxes; chambers; fill
What are the stages involved in the cardiac cycle?
- Ventricle filling: mid-late diastole
- Ventricle systole
- Isovolumetric relaxation: early diastole
How long is each cardiac cycle?
0.8s
- 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
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
- 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 ..?..
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
