PhysioEx 8.0 Exercise 6: Activity 9

This is all I have for that section:

Activity 9: Assessing the Effect of Various Ions (p. 79)

6. Calcium increases the strength of contraction; probably induces spasticity.

• The heart rate does not stabilize until 23°C Ringers solution is applied.

• The heartbeat is irregular, speeding up at times, slowing down at others.

Sodium decreases the strength and rate of contraction.

• The heart rate does not stabilize until 23°C Ringers solution is applied.

• The heartbeat is irregular, speeding up at times, slowing down at others.

Potassium weakens cardiac contractions.

• The heart rate does not stabilize until 23°C Ringers solution is applied.

• The heartbeat decreases considerably at first, then becomes erratic—alternately speeding up and slowing down.

Yes, all three ions may induce arrhythmias.

Thank you, Duddy! Much appreciated. Now I will go back through those. It's the only way I'll learn it!

in Activity 9, was there any evidence of premature beats in the recording of potassium ion effects?

Potassium weakens cardiac contractions.

• The heart rate does not stabilize until 23°C Ringers solution is applied.
• The heartbeat decreases considerably at first, then becomes erratic—alternately speeding up and slowing down.

It induces arrhythmias.

Duddy, 

   Can you give me the Why this happens with calcium ions specifically I'm kinda stuck.

Ok thank you.