Biophysics

The sound wave travels within the medium M1 and enters the medium M2 crossing the interface between these two media. The acoustic impedance for M1 and M2 are 3 kg.m-2s and 1 kg.m-2s, respectively. Indicate the value of the reflection coefficient

The ultrasonograph emits a pulse of ultrasound wave into the examined material at time t=0. The echo is detected after 0.2 ms (millisecond). Assuming the sound velocity in the material 500m/s, indicate the distance between the ultrasonography’s head and the object from which the sound was reflected:

The Fourier theorem concerns

ectric 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

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)

Idicate the correct definition of the magnetic field induction (B) unit (abbreviation: N-newton, A-

amper, m – metre)

 Indicate which nuclei are endowed with magnetic moments

order the tissues with respect to proton densities (from highest to lowest) Abbreviations: CSF

–cerebrospinal fluid, GM – grey matter, WM – white matter

Magnetization M is

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

chemical shift in the NMR spectra is related to

 Indicate the true sentence

to determine images dependent mostly on proton density, the operator needs to set recordings at (abbreviations: TR – repetition time, TE – time to echo)

Choose the correct statement for the neuromuscular junction:

Indicate the phenomena that do not contribute to electrodiffusion:

Which objects within the human’s body have the highest (nearly total) ability to reflect the ultrasound beam:

 Sound velocity:

 We consider an artificial lipid bilayer to which some non-selective channels (channels permeable equally to anions and cations) were incorporated. The resting potential of this embrace will take thevalue: (assume that electrolytes surrounding the membrane are physiological, i.e. on one side cytoplasmic and on the other extracellular)

The considered system can be found in the two states: energy U1 and state S2 characterized by the energy U2:

lectric 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:

At the resting membrane potential of a typical neuronal cell, the values of electrical driving forces for

potassium and sodium ions are approximately

 Considering a continuous flow of and ideal fluid through a cylindrical vessel, indicate how will change thevelocity of the fluid flow if the vessel’s radius is increased 3 times (Assume that the pressure indicatingthe flow does not change)

 If we measure for the sake of experiment, the aterial blood pressure to a subject in the standing position while the cuff is placed on the calf then the measured values of systolic/diastolic pressures will read:

We consider an artificial lipid bilayer to which some non-selective channels (channels permeableequally to anions and cations) were incorporated. The resting potential of this embrace will take the value:

(assume that electrolytes surrounding the membrane are physiological, i.e. on one side cytoplasmic and on the other extracellular)

 When a viscous fluid is transported through a cylindrical vessel of constant diameter and under a constant pressure, the fluid velocity;

The diameter of a cylindrical artery transporting a viscous fluid (blood) was reduced due to the growth of an atherosclerotic plaque to 25% of its physiological value.

Indicate a true sentence

The velocity of propagation of the pulse wave along the arterial vessels is:

 What happens to the optical power of a symmetrical lens of one of its curvature radii decreases 3 times (is becoming one third of the original value) and the other re- mains unchanged?

 Indicate correct concept of the voltage-calmp technique:

Indicate in which case the action potential is not propagated with a constant amplitude:

 GABA(A) receptors are

Indicate how the average kinetic energy (Ek) of a gas particle is related to the gas velocity:

The entropy is ( p – pressure, N- number of characterizing a given macrostate, V- volume, R- gas constant, Q- heat, T- temperature):

 For the open system the chemical potential for a given compound can be described as:

How the osmotic pressure ( according the V ant Hoff ) depends on the temperature:

 The change in free enthalpy ∆G) is equal to zero for:

 In the case of the ideal gas internal energy comprises:

 In an isolated system which a local (i.e. within the system) transfer of heat (del- taQ) takes place at temperature T, the change in entropy, is given by (U-internal energy, p-pressure, V-volume)

the closed system containing the ideal gas is expanding (increasing its volume) without changing heat with the environment. The internal energy of this system is: