Cardiac Cycle Tournament
Ten TEAS-style rounds: S1 vs S2, isovolumetric contraction, the cycle sequence, conduction and valves, stroke volume, true/false on flow, what is not systole, and when the aortic valve opens.
Where the Striated muscle contraction fits in Muscle contraction
Cardiac myocytes are striated muscle with a pacemaker wrap. This Reactome map is the contractile machinery that turns each electrical cycle into ejection. Click the highlighted striated-muscle panel to enter the tournament.
Click the highlighted Striated muscle contraction box to continue.
What this tournament tests
Each task maps to a distinct ATI TEAS cognitive demand. The first two orient you in the broader topology; the next 8 test the high-yield mechanism, regulation, sequence and quantitative reasoning that consistently appear on test day.
The Bigger Picture
Place cardiac muscle on the Reactome contraction map.
Whole-Pathway Overview
Pan the WikiPathways striated-muscle figure.
Fill in the Blank
Name the valves that make S1.
Disruptor
Recognize isovolumetric contraction from a pressure-volume clue.
Sequence Ordering
Order one full cycle from atrial systole.
Match the Pairs
SA node, AV node, valves, Purkinje.
Numeric Input
Compute stroke volume from EDV and ESV.
Select All That Apply
True statements about sounds and flow.
Odd One Out
Which event is diastole, not systole.
Pressure Disruptor
At what LV pressure the aortic valve opens.
Public leaderboard
Your score posts to a global, persistent leaderboard scored by points first, time as tiebreaker.
Cardiac cycle in 60 seconds
S1 = AV valves closing as systole starts. S2 = semilunar valves closing as diastole starts.
Between those sounds sit two sealed-chamber phases — isovolumetric contraction and isovolumetric relaxation — when all four valves are shut.
Stroke volume = EDV − ESV. The SA node starts the beat; the AV node delays it so the atria finish emptying.
TEAS items love the sealed-chamber clue: if ventricular pressure is rising and all four valves are shut, you are in isovolumetric contraction — after S1, before the aortic valve opens.
FAQ
What makes S1 and S2 on the TEAS?
S1 is the AV valves (mitral and tricuspid) closing as ventricular systole starts. S2 is the semilunar valves (aortic and pulmonary) closing as diastole starts. 'Lub' is S1; 'dub' is S2.
What is isovolumetric contraction?
The slice of early systole when ventricular pressure is rising but every valve is shut, so volume does not change. It ends when LV pressure exceeds aortic pressure and the aortic valve opens.
How do I calculate stroke volume?
SV = EDV − ESV. End-diastolic volume is the filled ventricle; end-systolic volume is what is left after ejection. Cardiac output is SV × heart rate.
Is this the same as the MCAT muscle-contraction game?
No. That page is sarcomere cross-bridges on a different exam URL. This tournament is the cardiac cycle — sounds, valves, and volumes — written for ATI TEAS 7 Science.
Keep going
The myofilament machine that turns each action potential into ventricular pressure.
How the kidney handles the blood the heart just ejected.
Overview diagram: Reactome Pathway R-HSA-397014, licensed CC BY 4.0. Reference figure: WikiPathways WP383.