1 / 10

Heart Conduction & Cardiac Cycle

Heart Conduction & Cardiac Cycle. Cardiac Circulation. Myocardium nourished by coronary artery Coronary veins drain into coronary sinus (enlarged vessel on backside of heart) Coronary sinus empties into right atrium. Heart Conduction.

jstapleton
Télécharger la présentation

Heart Conduction & Cardiac Cycle

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Heart Conduction & Cardiac Cycle

  2. Cardiac Circulation • Myocardium nourished by coronary artery • Coronary veins drain into coronary sinus (enlarged vessel on backside of heart) • Coronary sinus empties into right atrium

  3. Heart Conduction • Cardiac muscle does not have to be controlled by nervous system • Muscle cells in different areas of heart have different rhythms

  4. Heart Rate influences • Autonomic nervous system increases & decreases heart rate • Intrinsic conduction system (nodal system) causes heart muscle depolarization (electric impulse that causes heart beat)

  5. Heart Beat • SA node (also known as pacemaker) • Located in right atrium • Starts heart beat • Impulse travels through atrium to the AV node • Atrium contract

  6. Impulse through AV bundle through bundle branches to Purkinje fibers in apex • Ventricle contracts starting at apex and moving toward the atria. • Blood forced upward out of the aorta

  7. Cardiac Cycle = complete heart beat • Atria contract simultaneously • Atria relax • Ventricles contract • Systole = contraction of ventricle • Diastole = relaxation of ventricle

  8. Mid to late diastole • Ventricle completely relaxed • Pressure low in heart • Blood flowing passively into and through atria into ventricles • Semilunar valves closed, AV valves open • Then atria contract, forcing blood into ventricles

  9. 2. Ventricular systole • Ventricles contract (atria relax-filling with blood) • Pressure increases, closing AV valves (lub sound) • Higher pressure in ventricles, than in arteries so forces semilunar valves open and blood is forced into arteries

  10. 3. Early diastole • Ventricles relax • Semilunar valves close (preventing back flow) • Dup sound • Intraventicular pressure drops, until low enough for AV valves to be forced open

More Related