Biophysics Final

A robust excess of extracellular potassium concentration ([K]_out) is known to lead to the cardiac arrest. Indicate most important cause of this effect: 

Indicate the fastest mechanism of communication between two cells

Nicotinic Acetylcholine receptors are:

Indicate the name of the disorder characterized by the following symptoms: muscle fatigability, deficit of acetylcholine receptors at the muscular endplates :

In myothonia congenita the skeletal muscle fibers are:

Considering the flow of ideal (non-viscous) fluid through a cylindric vessel, indicate how will change the velocity of the fluid flow if the vessel’s length is increased 3 times (we assume that the pressure inducing the flow does not change):

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 part of the arm kept high above the head, then the measured values of systolic/diastolic pressures will read:

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

Parameter Q defines the volume of viscous liquid transported per unit time through a cylindrical vessel. If the radius of the vessel are reduced by 50% and its length is increased twice (100% increase) how much the parameter Q will change (assuming that all other parameters including pressure and liquid viscosity remain the same) ?

Indicate the orders of magnitude for number of photoreceptors and ganglion cells in the human eye retina

A symmetrical spherical lens changed its shape by increasing the curvature radius 4 times. How such a deformation will affect the optical power ?

When the degree of order in the isolated system increases 

Thermodynamically, the process of diffusion can be regarded as 

For the open system the chemical potential (µ) for a given compound can be described as

When cells are suspended in a hypotonic solution:

In the harmonic movement a particle is oscillating around the equilibrium point and A denotes the amplitude i.e. the maximum absolute distance of particle from the equilibrium point. Indicate the situation in which the absolute value of the harmonic force (F) is reaching its maximum: (y – distance from equilibrium point, -A ≤ y ≤ A).

1. If the medium density increases two times but the speed of acoustic wave propagation does not change then the acoustic impedance is

The incoming acoustic stimulus has induced a deformation of the basilar membrane very close to the oval window. We may deduce that the detected voice 

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

1. Find the true statement

Blood velocity in the vessels can be estimated when applying:

Indicate proper statement regarding X and gamma rays

The feature that a lens focuses the light not at a focal point but at a blurred spot is referred to as:

Typically, the wavelength of absorbed photon is:

The energy of interaction between the magnetic moment and the external magnetic field is minimal when:

In the MRI scanning, the gradients of magnetic field are used to: 

Indicate in which units is measured the ECG signal:

Indicate where in the heart tissue, the propagation of excitability occurs with the lowest velocity

Sensory neurons are typically:

In the electrolyte, local intensity of electric field 

Assuming that the membrane voltage is 100 mV and the membrane thickness is 10 nm, the intensity of electric field is: 

The intracellular concentration of chloride ions is increased while the extracellular one remains unchanged. Indicate how this change will affect the value of the equilibrium potential for chloride ions (V_Cl). 

In an electrophysiological experiment the number of moles of electrical charges per membrane surface unit and per unit time is determined. The name of the physical quantity measured in this experiment is:

The phenomenon of diffusion is quantitatively described by:

Indicate a typical width of the synaptic cleft (distance between pre- and postsynaptic membrane) of a chemical synapse:

The speed of the acoustic wave in an elastic medium is: (E - volume elasticity module, r- medium density)

The sound velocity is measured in the air, water and in a metallic crystal. The sound velocity is found to be: 

Indicate the tissue in which the speed of the acoustic wave is characterized by the largest velocity:

The sound intensity is defined as: