Final Exam Chapter 14 review Flashcards
How does the tricuspid valve prevent backflow of blood?
Pre contraction the papillary muscles are contracting and holding onto the Chordae tendineae. When the big contraction happens in the right ventricle the force of blood will go under the cusps of the Chordae Tendineae and close. The papillary muscles contract and allow the cusps of the Chordae tendineae to close and not invert so the blood doesn’t back flow.
What is Depolarization Plateau of the cardiac muscle contraction?
It is where there is calcium influx in the cardiac muscles and it creates a longer refractory period so the heart doesn’t contract as often so the heart can rest. In the heart we do not want to contract super often like we want in skeletal muscles.
What is the pacemaker in the body? What makes it the pacemaker?
The SA NODES, It is where the heart patterns of each heart beat start
What type of receptors are in the SA nodes of the heart? Why?
The baroreceptors because it gets stimulated by pressure
How does the heart contract in such a regular rhythm (consider cells structure and movement of conduction pathway through cells)
By the SA node (pacemaker) which automatically sends electrical signals. the myocardium also helps by spontaneously contracting sending the signal down. And if the SA node is broken then the AV node and Purkinje fibers will work as secondary pacemakers (ectopic pacemakers) and send electrical stimulus just at a slower rate.
What is afterload?
It is aortic pressure that the left ventricle needs to overcome to eject blood. (decrease in afterload decrease in stroke volume)
