2/26- Frog Heart (Exam 2) Flashcards
What is the little hump?
Atrial contraction
What is the big hump contraction?
Ventricular contraction
What does the ringers solution at 23 C do?
Normal heart rate
What does the ringers solution at 32 C do?
Heart rate speeds up
What do the ringers solution at 5 C do?
Heart rate slows down
What 2 chemicals speed up a frogs heart?
1) epinephrine
2) atropine
What 2 chemicals slow the heart rate of a frog?
1) pilocarpine
2) digitalis
What does pilocarpine act like?
Acetylcholine
Parasympathetic nerves
What does epinephrine act like?
Sympathetic nerves
What does atropine act like?
Blocks action of acetylcholine
Blocks Neurotransmitter of parasympathetic nerves
Fight or flight
What does a single electrical impulse near the ventricular contraction will result in?
Double systole
What is the pause called when double systole happens?
Compensatory pause
What happens when calcium ions is added?
Ventricular contraction is slightly stronger than normal
What is excess blood calcium levels known as?
Hypercalcemia
Prolongs plateau phase of cardiac muscle action potentials
What happens with sodium ions?
Ventricular contraction is slightly weaker than normal
What is excess blood sodium levels known as?
Hypernatremia
Inhibits calcium transport into cardiac muscles weakening heart contractions
What happens when potassium ions are added?
Stops atrial contraction completely
Ventricular contractions are weaker
What is excess blood potassium levels known as?
Hyperkalemia
Extra K lowers the resting potential and interferes depolarization
What happens with an electrical stimulation of the vagus nerve?
Heart slows down and weakens
Eventually heart stops but then begins on its own
What is it called when the vagus nerve stops the heart and then starts again?
Vagal Escape
