Chapter 18.4 Cardiac Cycle-Cardiovascular System Flashcards
What is cardiac cycle?
Cardiac cycle is all events involved with blood flow through heart during one heartbeat
What is systole?
Contraction phase
what is diastole?
Relaxation phase
Explain 1-3 steps of cardiac cycle
- Atrial systole-Atria contract and AV valves open; add blood to fill the ventricles
2.AV valves close to prevent backflow, causing first heart sound “lub”
3.Atrial diastole-Atria relax, and blood flows into right atrium from superior and inferior vena cavae, and into left atrium from pulmonary veins
Explain 4-6 steps of cardiac cycle
4.Ventricular systole-ventricles contract; AV valves closed; semilunar valves open; blood flows into Pulmonary arteries from right ventricle and Aorta from left ventricle
5.Ventricular diastole-ventricles relax and semilunar valves close due to pressure in pulmonary veins /aorta, causing second heart sound “dub”
6.Pressure in ventricles decreases–AV valves open and Blood begins to flow from atria to ventricles (back to step 1)
Does blood being pumped through heart chambers exchange nutrients / metabolic end products with myocardial cells
No
What does blood being pumped through heart chambers receive?
their blood supply via arteries that branch from aorta
How does blood being pumped through heart chambers receive oxygen and nutrients to myocardial cells
From Coronary arteries (coronary blood flow)
Where does blood being pumped through heart chambers exit
from behind aortic valve cusps in first part of aorta
Where does blood being pumped through heart chambers lead to?
branching network of small arteries, arterioles, capillaries, venules, and veins similar to those in other organs
What is pathway for most cardiac veins?
Most cardiac veins drain into coronary sinus, which in turn empties into right atrium
