Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
12 Cards in this Set
- Front
- Back
|
why is rhythm of pacemaker cells important?
|
rate that pacemaker cells fire AP sets heart rate
|
|
|
what are:
-pacemaker cells -contractile muscle cells |
-undergo spontaneous APs, do not contract, have their rhythm (autorhythmic)
-excitable, produce mechanical pumping |
|
|
where are pacemaker cells located
|
Sinoatrial node (SA) of R atrium
|
|
|
how are APs passed from cell to cell
|
via gap junctions at electrical synapses
|
|
|
what prevents ventricles from contracting at same time as atria?
|
atrial cells are insulated from ventricular cells
|
|
|
spread of depolarization is delayed where?
-why is this important |
at the AV node
-allows ventricles to fill |
|
|
there is no resting potential in pacemaker potentials
-what occurs between action potentials |
ya
-pacemaker potentials |
|
|
what sets the heart rate?
|
the slope of the pacemaker potential in SA node
-slope = time to reach threshold |
|
|
how fast would a human heart beat on its own?
|
100 bpm
(typical is 60-100) |
|
|
what is responsible for decreasing resting Heart Rate
|
the vagus nerve which is a parasympathetic neuron
|
|
|
what are the types of efferent nervous systems
|
somatic (voluntary, motor) and autonomic (involuntary)
|
|
|
what are two sides of autonomic nervous system
|
sympathetic and parasympathetic
|
