Contraction and Conduction Flashcards
Difference between skeletal and cardiac cells
skeletal: long, thin cells, unbranched, multiple nuclei
cardiac: short, thick cells, branched, single nuclei, intercalated discs
Pacemaker function
inititates each heartbeat and determining heart rate
Where are pacemakers found
right atrium *update to be in nodes
Conducting cells function
specialized cardiac muscle cells *update
Contractile cells function
produce contraction that propel blood
Where are conducting cells found
myocardium
How does the conducting system work?
initiates and distributes electrical impulses that stimulate contraction
Steps of the conducting system
- SA node fires
- excitation spread through atrial myocardium
- AV node fires
- excitation spreads down AV bundle
- subendocardial branches distribute excitation through ventricular myocardium
What are sinoatrial (SA) nodes
patch of cardiomyocytes in the wall of the right atrium
SA nodes function
pacemaker that intiates each heartbeat and determines heart rate
Atrioventricular (AV) nodes function
electrical gateway to the ventricles
Where does the AV node receive impulses from?
SA nodes
What is the AV bundle
pathway by which signals leave the AV node
Where is the AV bundle located?
in the septum
Where does the AV bundle carry impulses to?
left and right bundle branches and to the moderator band
Subendocardial branches (Purkinje fibers) function
distributes impulses through the ventricles
What is pacemaker potential
resting potential of conducting cells
