Final answer:
When norepinephrine binds to a beta adrenergic receptor on the ventricular contractile cell, there will NOT be an increase in calcium influx through the opening of membrane calcium channels. Instead, other events such as an increase in cyclic AMP, calcium release from the sarcoplasmic reticulum, and slow depolarization will occur.
Step-by-step explanation:
When norepinephrine binds to a beta adrenergic receptor on the ventricular contractile cell, the event that will NOT occur is an increase in calcium influx through the opening of membrane calcium channels. The binding of norepinephrine to the receptor activates a G-protein, which in turn activates adenylyl cyclase, leading to an increase in cyclic AMP. This increase in cyclic AMP results in an increase in calcium release from the sarcoplasmic reticulum, known as calcium-induced calcium release. Additionally, norepinephrine binding to the beta adrenergic receptor also leads to an increase in slow depolarization, which plays a role in initiating the firing of action potentials.