KROK 1 2008 – Question 165 · KROK (Medicine) · Physiology
A cardiac electric stimulator was implanted to a 75 year old man with heart rate of 40 bpm. Thereafter the heart rate rose up to 70 bpm. The electric stimulator has undertaken the function of the following heart part:
- A. Sinoatrial node
- B. Atrioventricular node
- C. His’ bundle fibers
- D. Purkinje’s fibers
- E. His’ bundle branches
Hint
Compare the intrinsic firing rates of the different parts of the cardiac conduction system with the heart rate before the implant and after it.
The answer, the explanation and a note on every option are available once you log in. The account is free: topic tests, a mock exam, mistake review and statistics.
More questions on Physiology
- A patient came to the hospital complaining about quick fatigability and apparent muscle weakness. Examination revealed an autoimmune disease that…
- A 60 y.o. patient has a reduced perception of high-frequency sounds. What structures’ disorder of auditory analyzer caused these changes?
- Power inputs of a boy increased from 500 to 2000 kJ pro hour. What can be the cause of it?
- In course of an experiment a skeletal muscle is being stimulated by a series of electric impulses. What type of muscle contraction will arise, if…
- A patient has a transverse disruption of spinal cord below the IV thoracic segment. What changes of respiration will it cause?
- A lightly dressed man is standing in a room, air temperature is +14 °C, windows and doors are closed. In what way does he emit heat the most actively?