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3 Fundamentals of the Formation of Biosignals

3.

What electrical properties do biomembranes have? Give orders of magnitude and

draw the equivalent circuit.

4.

Explain the term electrogenic transporter. What forms do you know, how do they

differ and what are their functions in the cell?

5.

In what form do biomembranes obtain their functionality? Describe them in rela-

tion to electrogenic transporters.

6.

Name the possible conformational changes of channel and transport proteins.

What is the function of each of these?

7.

What forms of excitation of channel proteins do you know? Explain the excitation

on the basis of the Na⁺ channel.

8.

What is meant by a resting membrane potential and how can it be explained?

9.

How does an action potential develop? Describe the exact process and the associ-

ated electrochemical processes in the cell.

10. Describe the excitation of a nerve cell across the synaptic cleft. What role does the

membrane threshold play in this process?

11. What is meant by the relative and absolute refractory period?

12. In what way does an increase in a stimulus affect an action potential? Within what

limits is this possible?

13. Describe the two forms of nerve conduction in the body. What are the differences

and in which animal species do the different forms occur primarily?

14. How do you explain the need for active conduction of the action potential?

15. What methods do you know to measure an action potential? What conclusions

can be drawn from such measurements? Name their applications in science and

technology.

16. Describe the central and peripheral nervous system. For example, in what form

does muscle excitation take place?

Electrophysiology of the Heart

1.

Describe the function of a pacemaker cell.

2.

Which pacemaker cells are present in the heart and what is their function?

3.

Can a pacemaker complex consisting of a cluster of these cells fail? If so, what

happens?

4.

How do the action potentials of a muscle cell and a pacemaker cell of the heart

differ? How do you explain these differences?

5.

How is the electric field created during cardiac excitation, is it like the electric

potentials on the surface of the body? What is meant by a current dipole, what by

a projection? How does the current dipole behave during the heartbeat?

6.

Give the time course of the potential on the body surface during a heartbeat. Into

which sections can the ECG signal be divided, and what meaning and association

with cardiac function can be established?