The most important controls on heart are by? Besides, what also play a role?
When Stress/Fright occur, they activate Sympathetic Fibers and do what?
Release of Norepinephrine to bind B1 receptors
The release of Norepinephrine cause what?
Pacemaker to fire more rapidly and lead to higher heart-beat.
What nervous system would sometimes oppose the Higher Heart-beat lead by Sympathetic?
Parasympathetic is mediated by what? And what's the consequence of the mediatation?
AcH; Pottasium Channels open
What will be released when Norepinephrine is being released during Sympathetic Activation?
NE enhances heart beat and contractility. What else do these?
The functions or effects or NE and Epinephrine are enhanced by?
HyperThyroidism cause what and why?
Weakened Heart, because it over-works the heart
Too much Calcium is called what?
Too much Calcium cause what?
Heart irritibility/ Spastic Heart Contractions
Low calcium called what?
Low calcium cause what?
Depress the heart action (contraction)
Too much Sodium is called what?
Too much Sodium cause what?
Block Heart Contraction
How Sodium block Heart Contraction?
By inhibiting the Calcium Ions go into the Heart
Too much Pottasium is called what?
What does Hyper-kalemia do?
lower the resting potential and interferes depolarization