Course

Course Summary

Credit Type:

Course

ACE ID:

CSRA-0004

Organization:

Coursera Inc.

Location:

Online

Length:

8 weeks (60 hours)

Dates Offered:

Credit Recommendation & Competencies

Level	Credits (SH)	Subject
Upper-Division Baccalaureate	2	Biology or Biomedical Engineering

Description

Objective:

The course objective is to provide a knowledge; of the rules of electricity in solutions the sources of energy across membrane, the generation of electrical pulses (action potentials) by bioelectric membranes, and the propagation of these action potentials along fibers; discuss the origins of extracellular signals, the ones normally observed in measurements such as the ECG, EEG, and EMG; and introduce some core ideas about electrical stimulation from within and outside the active cells.

Learning Outcomes:

Interpret the polarity of Vm in terms of voltages inside as compared to outside cells
Describe the function of the sodium-potassium pump
State from memory an approximate value for RT/F
Explain the mechanism by which membranes use salt water to create negative or positive trans-membrane voltages
Describe the opening and closing of a channel in terms of probabilities
Given the rate constants alpha and beta at a fixed Vm, determine the channel probabilities
Compute how the channel probabilities change when voltage Vm changes
Describe the purpose of each of the 4 model levels (1) alpha/beta (2) probabilities (3) ionic currents (4) trans-membrane voltage
Estimate the change in trans-membrane potential over a short interval
Select the characteristics that distinguish core-conductor from other models
Given a list of trans-membrane potentials, decide where axial and trans-membrane currents can be found
Compute axial currents in multiple fiber segments from trans-membrane potentials and fiber parameters
Quantify the interval after propagation following one stimulus to the time when there will be another excitation wave following a 2nd stimulus
Explain what the 'activation function' is
Draw a strength-duration curve, and explain what it is
Explain the concept of 'threshold' and give examples of threshold values
Explain the conflict between Galvani and Volta
Interpret the polarity of Im in terms of current flow into or out of a cell
Determine the energy in Joules of an ordinary battery, given its specifications
State the 'big 5' electrical field variables (potentials, field, force, current, sources) and be able to compute potentials from sources (the basis of extracellular bioelectric measurements such as the electrocardiogram) or find sources from potentials
Find the equilibrium potential from ionic concentrations and relative permeability
Describe the passive as compared to active responses to stimulation
Estimate changes in each probability over a small interval
Compute the ionic current of potassium, sodium, and chloride from the state variables
State which ionic current is dominant during different phases of the action potential -- excitation, plateau, recovery
Identify the differences between axial and trans-membrane currents
Compute membrane currents at multiple sites from trans-membrane potentials
Identify the differences between the propagation pattern following sub-threshold versus threshold stimuli
Compute the changes in trans-membrane potentials and currents from one time to a short time later
Identify the outcome of stimulating a fiber at both ends
Explain why 'propagation' is different from 'movement'
Identify and the quantify the sources of extracellular potentials in terms of membrane currents
Recognize which side of an excitation wave is positive, and which is negative
Describe the sources and characteristics of no fewer than 3 kinds of extracellular bioelectric measurements, including the important features used in interpreting them
In equation form, show the dependence with distance of a unipolar extracellular stimulus electrode
Draw a strength-interval curve, and explain what it is

General Topics:

Electricity in solutions
Energy- pumps and channels
Channels - how membrane walls allow ions to pass through
Hodgkin-Huxley model - how membranes generate action potentials by sequentially allowing ions of sodium and potassium to flow
Axial and trans-membrane currents within and around the tissue structure
Propagation - sequences of action potentials
Extracellular observations - time-varying voltages between electrodes
Trans-membrane and field stimulation to initiate or control excitation
Evolutionary applications and misapplications
Adaptive behaviors and species formation