Course detail

Bioelectric Phenomena

FEKT-BPC-BEJAcad. year: 2024/2025

Physical interpretation of electric phenomena in living tissue constitutes a special area of biophysics. The subject ‚Bioelectric phenomena‘ acquaints the students with biophysical basis of the genesis of electric signals on different structural levels , with passive electric properties a of living tissue, and with currently available methods of bioelectric measurements.

Language of instruction

Czech

Number of ECTS credits

5

Mode of study

Not applicable.

Entry knowledge

Knowledge of biology, mathematics and physics accordant with the subjects of previous bachelor’s study is expected.

Rules for evaluation and completion of the course

The final grade for the course will be determined by the scores obtained from the midterm tests and the activity exercises (max. 30 points in total) and the final written examination (max. 70 points).   

Only students who have been awarded credit may take the final exam.

- obtaining at least 15 points in the laboratory exercises, including points for the continuous written tests,

- a non-zero score on the continuous written tests,

- a non-zero score on the protocols or homework assignments,

- meeting full attendance requirements, 

- obtaining at least 50 % of the marks on the final examination.  


Extent and forms are specified by guarantor’s regulation updated for every academic year.

Aims

To teach the students how to apply the knowledge acquired by previous study of physics and mathematics to understand mechanisms underlying origin of electric signals in living organisms

Passing the subject, the student is able:
- to explain genesis of membrane voltage in the living cells applying the known physical laws and to define quantities that appear in the Nernst formula for equilibrium voltages,
- to describe electrical equivalent scheme of the cell,
- to explain origin of action voltages in excitable cells and mechanism of its propagation along cell fibers,
- to describe principles of the methods of measurement of membrane voltage and membrane current,
- to characterize electrical signals recorded on cellular and molecular level and to explain their mutual relations,
- to define the terms “chemical potential’’ and ‘’electrochemical potential’’,
- to describe the relation between the propagated excitation at the level of cell and genesis of electromagnetic field in the surrounding tissue,
- to explain principles of excitation-contraction coupling in muscle cells,
- to describe origin of ECG signal as a result of action voltage propagation in the net of cardiac cells (syncytium),
- to prepare physiological solutions including measurement and adjustment of their pH, to measure tissue impedance and properties of the electrodes.

Study aids

Not applicable.

Prerequisites and corequisites

Not applicable.

Basic literature

F. Bezanilla: Electrophysiology and the Molecular Basis of Excitability. (University of California at Los Angeles) Volně dostupné na adrese http://nerve.bsd.uchicago.edu/ (EN)
J. Šimurda: Bioelektrické jevy I, CERM Brno, 1995 (CS)
J.Šimurda, Bioelektrické jevy, elektronická skripta 2007 (CS)
S. Silbernagl, A. Despopoulos: Atlas fyziologie člověka, GRADA Publishing a.s. 2004 (CS)

Recommended reading

Not applicable.

Elearning

Classification of course in study plans

  • Programme BPC-BTB Bachelor's 3 year of study, winter semester, compulsory

Type of course unit

 

Lecture

26 hod., optionally

Teacher / Lecturer

Syllabus

1. The origin and functions of electric signals in living cells. Membrane voltage.
2. Action voltage and its physiological significance. Propagation of action voltage down cellular fibres.
3. Possibilities of obtaining electric contact with the cell interior. Methods of measurement of membrane voltage and membrane currents.
4. Physical principles of bioelectric effects. The model of the cell for interpretation of electric effects.
5. The quantitative relationship between the overall ion membrane current and action voltage. The main components of ion membrane current and their characterisitcs.
6. Physical interpretation of propagation of excitation down cellular fibres. Biophysical description of electric effects by systems of differenetial euqations.
7. Interpretation of bioelectric effects on molecular level. The structure and functions of biological membrane.
8. Membrane channels: transitions between channel states (gating). Measurement of membrane electric currents on molecular level (the ‚patch clamp‘ method).
9. Carrier-mediated transport of ions across biological membranes. Interaction of substances with transport systems (the mechanisms of effects of some drugs and toxic substances).
10. Excitable cell as a source of electromagnetic field in the surrounding environment. Biophysical principles of electrophysiological diagnostic methods.
11. The electrocardiographic and magnetocardiographic signal as a consequence of action voltage propagation in the network of interconnected heart cells.
12. Excitation-contraction coupling in muscle cells.
13. Measurement methods of electromechanical properties of cardiac cells, tissue and heart.

Laboratory exercise

26 hod., compulsory

Teacher / Lecturer

Syllabus

1. Measurement of electric properties of metal electrodes for recording of bioelectric signals
2. Preparation and measurement of the properties of glass microelectrodes.
3. Preparation of solutions for cellular electrophysiological measurement. Measurement of pH.
4. Measurement and analysis of ion membrane currents in excitable cells (simulation experiments).
5. Measurement of excitation threshold.
6. Measurement of electric impedance in living tissue.
7. Recording of contractions in isolated heart cells.
8. Excursion to the laboratory of cellular electrophysiology
9. Electric properties of cellular membranes (numerical exercises)
10. Measurement of membrane voltage and membrane currents (seminar with demonstration)
11. Molecular basis of bioelectric effects (inatractive software)
12. Propagation of electromagnetic field generated by heart (numerical exercises)
13. Electromechanical coupling (interactive software)

Elearning