BIO271H1 Lecture 10: Notes
Document Summary
The sequence of events from one heart beat to the next. We have many cardiac cycles in series/sequence. Contraction and emptying heart muscles contracts and the blood empties. Will allow sodium and potassium to move through, but the driving force on the sodium is much stringer so sodium moves much more quickly in to the cell causing a depolarization. Norepinephrine is released from the sympathetic neurons and epinephrine is released from the adrenal medulla. When this happens, there are more funny and t-type calcium channels open (due to secondary gpcr pathway) This increases the rate of depolarization ad frequency action potentials. Kicked out of the world cup for testing positive for. Leads to an increase in time for depolarization and a decrease in the frequency of action potential and a decrease in heart rate. Rate of pacemaker potential determine heart rate: sympathetic system. Potential rises rapidly and frequency of action potential increases.
