Biophysics

190) Indicate in which mechanism the energy of photon is totally absorbed

 

192) In the Geiger-Muller counter
 

194) Astigmatism takes place when:

 

195) To obtain the image of a single slice of patient’s body during MRI scan one should use:

 

196) Neuron is referred to as bipolar when

 

199) What happens to the membrane capacitance of a cell if both its surface area and thickness increase
two fold (two times)?
 

204) If the input resistance of a cell membrane is 100MOhm (megaOhms) and its capacitance is 100 pF
(picoFarads), the time constant of the membrane is
 

207) Indicate the type of channel responsible for a slow depolarization of the diastolic potential in the sinoatrial node
 

209) When ventricles are completely depolarized the ECG recording shows

 

210) Repolarization of atria is represented in the ECG by

 

212) If we measure, for the sake of experiment, the blood pressure to a subject in the standing position and
the cuff is placed on the leg close to the foot, then the measured values of systolic/ diastolic pressures
will read:
 

214) Chemical shift in the NMR spectra is related to:

 

217) In the harmonic movement a particle is oscillating around the equilibrium point and y denotes the
distance of particle from the equilibrium point. The harmonic force (F) inducing the harmonic
movement is described as follows (k is the spring constant):
 

218) Choose the correct statement for the neuromuscular junction:
 

219) Indicate the phenomena that do not contribute to electrodiffusion:
 

220) Sound velocity:

 

221) Ultrasound beam is propagated through a soft tissue and enters one indicated below. Indicate when the
reflection will be minimal:
 

222) At a defined frequency (1000 Hz) how much the sound intensity needs to be increased to increase the
sensation of sound loudness by 200%
 

223) Two sounds were found to be characterized by the same basal frequency but different weights of higher
harmonics. When listening these sounds we will report that
 

225) The major role of the outer hair cells in the Corti apparatus is

 

226) Electric charge q is moving with velocity v in the magnetic field characterized by induction B. Assuming
that velocity vector is perpendicular to the induction vector B, the force acting on the charge will have
the orientation:
 

227) In which conditions a proton in the presence of external magnetic field (B0) is in the state characterized
by the highest energy (µ is the magnetic moment of the proton)
 

231) Relaxation time T1 describes the process (symbols: Ms is the component of
magnetization M parallel to external magnetic field B0)
 

233) Electric field is applied to invert the MZ and then the time course of magnetic changes are measured
 

234) What happens to the membrane capacitance of a cell if both its surface area and thickness increase
two fold (two times)?
 

235) Indicate the effect of the inward (from outside towards inside the cell) current of anions flowing through
the cytoplasmic membrane
 

237) If the intracellular concentration of a cation is larger than the extracellular one, the Nernst equilibrium
potential for this ion is:
 

238) Indicate the effect of hydrogen bonding on phase transition in water
 

241) When the function of the f channels in the SA node is increased:

 

242) The first principle of thermodynamics for ideal gas states that the change of internal energy of a closed
system is equal to:
 

44) The sample contains 2000 atoms of radioactive isotope whose half-life is 50 years. Radioactive decays
will reduce the initial number of radioactive atoms to 125 after:
 

246) Van der Waals attractive interactions are due to:

 

247) After a light absorption by a photoreceptor the membrane potential:

 

248) The force of electrostatic interaction between two electrical charges is:

 

249) The energy of interaction between two dipoles is:

 

250) Which mode(s) of ultrasonography provides a direct information about the amplitude of echoes:

 

257) During MRI scan a patient is placed in the constant magnetic field of a scanner and the protons in
patient’s body absorb pulses of electromagnetic radiation whose frequency is typical for:
 

260) The NMR phenomenon is related to:

 

262) The intensity of the electrical field (E = U/d, U – voltage, d – distance) within the biological membrane is
close to:
 

268) Accommodation of the eye is related to: