We take an ECG for a patient that has been feeling fatigued. We notice that there is a large delay between their T and P waves. From this information, where is this patient likely having an issue? O Left and Right Bundle Branches O Purkinje Fibers O Atrioventricular Node O Sinoatrial Node O Bundle of His A O O O 0O

What does this ECG show? Vi V4 aVL V2 VS aVF V3 V6 10 3d degree AV block 2 0 LBBB 3 O Left anterior hemiblock 4 O Ist degree AV block

In the following graphs of pacemaker potential recordings from the SA node, what graph represents what (ie parasympathetic nerve effect)

When does isovolumetric relaxation occur?   A immediately after atrial contraction   B at the end of diastole   C immediately after the QRS wave on the ECG   D immediately after ventricular contraction   E ALL OF THE ABOVE

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2.A. 1. 2. 3. 4. |||| ential (mv) 13. State the channels involved in an action potential in cardiac AUTORHYTHMIC cells, which ion moves across the channel, which direction each ion moves across the channel when the channel opens, the approximate membrane potential at which the channel is fully open. +20 !!| CE - | Channel AaBbCcDdEe AaBbCcD. AaBBCEDE Aal Emphasis Heading 1 Normal lon? Influx or Efflux? 14. Define the term pacemaker potential (=drifting potential) and be able to identify it when given a graph of an action potential in an autorhythmic cell such as the one below. I Membrane Potential at which channel opens or is fully open (mv)

When we flung our arms around on the first day of class our heart rate increased to meet the demands of our exercising muscles. What was the mechanism by which this occurred? O Norepinephrine bound to receptors on the SA and AV nodes of the heart O The excess CO2 in the plasma generated by our skeletal muscles directly stimulated our cardiomyocytes to contract more frequently O Parasympathetic postganglionic neurons released acetylcholine onto the SA and AV nodes of the heart

In an EKG reading: | the P wave corresponds to the AV node firing. the QRS complex corresponds to a time when ventricular pressure is greater than atrial pressure. When in sympathetic mode, the AV Bundle will be receiving impulses at a faster rate then when in parasympathetic mode. | The T wave represents the time when the SA node first fires. The P-R interval represents the delay that occurs when the AV Bundle transmits signals to the Purkinje fibers.

Cardiac myocytes are mechanically connected via O Gap junctions O Autorhythmic cells O Purkinje fibers O Desmosomes O Tight junctions

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