Explain all the electrical and mechanical events which occur during each measured wave, segment and interval. An electrical event would be membrane polarization: depolarization, repolarization, resting membrane potential, hyperpolarization etc; mechanical events include blood flow, open or closed valves, heart sounds, contraction, relaxation, pressure changes, etc. An example of a complete answer for the P wave is given below. Feel free to use your lecture and/or textbook as a reference to make the connections between ECG and the cardiac cycle. This is a great way to review for the exam and apply what you are learning. P Wave – During the P wave, depolarization is sweeping from the SA node throughout both atria (electrical event). This leads to the beginning of atrial contraction (mechanical event). PR Interval - P-R Segment – QRS Complex – Q-T Interval – S-T Segment – T Wave – T-P Segment – R-R Interval –

6. Please help answer all parts to this question, thank you so much!! :)

2. Circle the correct bolded blue word. a. A substance that moves across a membrane "down" or "with" their concentration gradient is moving from the side with a higher / lower concentration of that substance to the side with a higher / lower concentration. This does / doesn't require energy input and is called active / passive transport. b. A substance moving "against" or "up" its concentration gradient is moving from the side with a higher / lower concentration of that substance to the side with a higher / lower concentration. This does / doesn't require energy input and is called active / passive transport. c. If the energy from the hydrolysis of ATP is directly used to pump the substance, the transport is called primary /secondary active transport. d. Ion-coupled transport is primary /secondary active transport and has two parts. First, the hydrolysis of ATP is used to power the creation of an ion concentration gradient. The ion is typically Na* or H*. Second, the energy stored in…

9. You are performing an experiment at with an artificial membrane (i.e not a living cell). You place a NaCl solution on each side of the membrane. You discover that if you place a 10-fold NaCl concentration gradient across this membrane (higher NaCl concentration outside than inside) you initially see a +20 mV membrane potential develop. If the Cl permeability is assigned a value of 1, what value would you assign to the Na" permeability? Assume 2.3RT/F = 60 mV.

Membrane Potential (mV) The Action Potential 1. Label the significant membrane potentials and phases of the action potential in a neuron. Indicate which gates are open/closed as well as the direction of the net movement of sodium and potassium ions across the cell membrane for A-G. +30- 0 -55-B -70- -80- 0 H [T E 2 F 3 Time (ms) G 4 5

9. If sodium permeability (Pna) increases compared to normal, what is the effect on the membrane potential? (determine: change in charge on the inside of the membrane and polarity)

List the steps involved in neurotransmitter release starting with depolarization and ending with exoctosis. Include 1) the relevant channel and dynamics of the transmembrane domains and subunits; 2) ionic movements; 3) the various stages of the vesicles and the proteins involved as well as their configurations. There are 4 main steps that you should include.