ETS biophysics 125

125問 • 1年前

問題一覧

Movement of what species are examined by galvanotaxis?

Granulocytes, fibroblasts, osteoblasts, nerve cells and ect.

Compute force of muscle which is required to upright stand on the fingers due to given picture. Where F is muscle force of soles , R- is gravitational force exerted on body. a=40cm, b=4cm are arms of forces F and R respectively. Mass of the body is 70kg, g=10m/s².

70N

How does viscosity depend on the temperature?

when temperature increases viscosity decreases

Wahat force of muscle is required due to held the object of 10kg depicted in the picture (g=10m/sec²)( gravitational force of which is applied to center of mass of elbow is negligible. R is gravitational force applying to held object , F is contraction force of elbow. a=5cm and b=30cm are corresponding arms of forces F and R.

600N

What organ monitors position and orientation of the various parts of the body?

somatosensory system

What is the responsible for β dispersion or Maxwell-Wagner dispersion?

These dispersions are caused by structural inhomogeneities of the materials such as cellular and organelle structures.

Point the isometric regime of muscle contraction: 1) Original length of muscle doesn’t change 2) Work isn’t performed for any external displacement of the object 3) During isometric regime P load is constant 4) Contraction velocity of muscle (V(P)) is independent of (P)

1,2

Tendon with length of 12 cm, area of 2mm² is extended by 2,9mm under the 68,6N. Compute Yung’s modulus of tendon.

142 ·107 N/m²

What is the responsible for γ dispersion at higher frequencies?

It is caused by Debye relaxations of various molecular dipoles.

In a bilipid layer during state transition from "liquid - crystal" to"gel" state the membrane thickness:

increases

What does the active transport depend on?

active transport depends on carrier proteins that penetrate through the cell membrane

What is the origin of extracellular electric fields and currents (directed and indirected electric currents) in biological organisms?

They can be generated indirectly as a result of ion transport in living cells or directly as a streaming potentials or even by piezoelectric effect

What is the stress (σ') which must be applied to extend the area A of a membrane by the amount ΔA. where Y' - is the specific modulus of elasticity

σ'= Y' ΔA/A

What causes minimum bleeding and pain during laser surgery?

cauterization of blood vessels and sealing of nerve endings

What is the transmembrane potential of dividing (cells of embryos or cancer cells) and nondividing (neurons or skeletal muscles)?

For dividing cells it alters between -10 and -30 mV, For nondividing cells -70 and -90 mV

Measurement of blood pressure is based on

Conversion of turbulent flow into laminar flow

Why osmotic pressure caused by nondissociated molecules depend on number of osmotic particles, not on the mass of the particles.

because large particles move at slower velocities, the small particles move at higher velocities

Concentration of potassium ions in one side of the lipid bilayer membrane is 103M , in another side is 10-5M.Determine resting potential which is created by these ions at 200C temperature. F=96500 C/mol, R=8,31 J/mol·K.

116mV

What is the principal equation (Hill’s equation) of muscle contraction: where a, b- are constants, P0-is maximum isometric contraction force, P-is load

V(P) = b( P0 - P )/P + a

Electromiography is

the registration of a electrical field of the muscle

What organ is responsible compensating of larger displacement as well as for left and right perturbations of the center of mass in order to maintain balance?

Hip movements

How called established time dependence of the viscosity?

thixotropy

What formula allows us to determine increase of the radius of a tube (Δr) as a function of the internal pressure (p).

Δr = pr2 / Yd

For person who is standing erect the blood pressure

above the heart in the head is lower than that it in the feet

How does bioluminescence imaging technique operate?

Light emitting properties of luciferase enzymes are applied to monitor cells and biomolecular processes in living subjects.

What information does X-Ray computed tomography (CT) provide that ordinary X-ray images do not?

Computed tomography have been developed to produce slice-images within body which provides depth information.

What substances mainly can cross cell membranes by facilitated diffusion?

glucose and most of the amino acids

What autoimmune diseases is caused by malfunctions of immune system like by producing of exceed number of TNF (tumor necrosis factor) protein?

Type 1 diabetes , rheumatoid arthritis, multiple sclerosis and Crohn’s disease

By what important characteristics the protein channels are distinguished?

they are often selective permeable to certain substances and many of the channels can be opened or closed by gates regulated by electric signals (voltage-gated channels) or chemicals that bind to channel proteins (ligant-gated channels)

When pulse waves of the heart partly become damped?

Pulse waves damped by the increasing of elasticity of the vessels walls.

What length of a sarcomere in the isometric mode induces the maximum force?

2,2 mkm

34-What is the main idea of Einthoven triangle method?

Localization of the excited parts of the heart by detecting the potentials at three points on the body, which are more or less equidistant from the heart

Why oxygen-rich tissue suffers more from irradiation than that with low oxygen content?

Because the oxygen is able to facilitate the transfer of radical sites between molecules or molecular components

What is the difference between galvanotaxis and electrophoresis methods which are based on impact of static electric field on cell movements?

In case of galvanotaxis the electric field doesn’t act as a driving force and predicts an active movement of the cell.

What is the difference between active transport and facilitated diffusion due to functions of carrier proteins?

in active transport it is capable of imparting energy to the transported substance to move it against the electrochemical gradient

When the contraction velocity of muscle becomes maximum based on Hill's equation

When P =0

What property of biological membrane is important for the dynamics of cell shape and for cell swelling?

In contrast to technical materials the biological membrane can easily be deformed in an isoplanar fashion, but cannot resist expansion.

Point the chemical potential:

µi=µi 0+RTlnai

In what vessel the Reynolds number does have the critical value?

in aorta

Lever system of scull with respect to neck is depicted in the picture. R is gravity force exerted on the scull, F-is extension force of back-bone muscle .Where a=8sm, b=2cm are the arms of forces F and R respectively.Compute force of muscle which is required to straight up position of head. Mass of head is 6 kg. (g=10m/s²)

15N

What terms of membrane can be estimated by Nernst -Equation at thermodynamic equilibrium?

Passively distribution of ions as a function of the electrical potential and electrical potential which is induced by an unequal distribution of ions

A patient is driven 20 mA current during 20 minutes upon general galvanization. Assume, all ions possess single valence , find number of positive and negative ions taking part in electro-conductivity.

1,5·1020ions

What behavior does the whole blood have?

pseudoplastic thixotropic

What is an important role of rubber elastic properties of tendons and ligaments?

They play an important role in the storage of mechanical energy in some periodic or suddenly occurring movements

How does the pressure drop depend on the area of flow?

The larger area of flow the smaller the pressure drop

Why Terahertz radiation is not expected to damage tissues and DNA unlike Xrays?

Because the Terahertz radiation is nonionizing

Growing ability of what biological systems are studied by the vibrating probe technique?

Single cells, follicles of insect eggs, growing embryos, muscle fibers and other organs and tissues

Compute force of muscle which is required to upright stand on the fingers due to given picture. Where F is muscle force of soles , R- is gravitational force exerted on body. a=42cm, b=3cm are arms of forces F and R respectively. Mass of the body is 70kg, g=10m/s².

50N

What is the passive electric properties of biological tissues?

Electrical resistance, conductivity, membrane capacity

What radiation has the greatest penetrating ability ?

gamma radiation;

What is the responsible for α dispersion?

Reactions in the electric double layer of all membranes (for example deformation of ionic clouds) are responsible for this

At what frequencies the α dispersion may occur?

At the frequency range below 10kHz.

What contraction is said to be isometric contraction?

when the muscle doesn’t shorten during contraction

In what therapeutic methods the low frequency currents and electromagnetic fields are being used?

It includes implanted stimulating electrodes, like cardiac pacemakers, various externally applied electrodes for stimulation of nerves (TENS=Transcutaneous Electric Nerve Stimulation)and eddy currents , induced by external coil, PEMF -techniques (pulsed electromagnetic field)

What behavior of synovial fluid prevents its exclusion from the cleft by hydrostatic pressure?

A large viscosity of this fluid in the joints (between 1 and 40 Paˑsec)

What model of viscoelastic system is corresponding to real living systems?

Maxwell-KelvinVoight system

What structures is examined thank to X-ray crystallography

penicillin, vitamin B12,DNA, biologically important molecules

Overexposures to IR radiation can lead to

Acute damage in the form of skin burns, or collapse of the circulatory system.

What is the light?

Light is the electromagnetic radiation in the wavelength region between about 400 and 700nm (1nm=10-9m)

The electroencephalography is:

the registration of electric signals which is produced brain

What definition is correct for Gray (Gy):

1Gy=1J kg-1

Absorbtion of high fields (HF) in biological systems is basically determined by ...

İts water content

Gating of protein channels is due to...

voltage gating and chemical (ligand) gating

What method based on the temporary and frequency dependency of the impedance of biological tissues?

rheography;

What organ is responsible compensating of small back-and-force perturbations of the center of mass (displacement less than 1,5 cm) in order to maintain balance?

Ankle movements

How does the linear velocity of blood depend on the area section of vessel?

inversely proportional

Which resistance is not found in organism tissues?

inductive ;

What method is termed by Impedance spectroscopy?

The measurement of dielectric properties of solutions and heterogeneous media

What is the dose equivalent unit which is representative for RBE(relative biological effectiveness)?

Sievert

For the membrane of erythrocytes a value of specific modulus of elasticity Y’is 0,45Nm-1, thickness of the membrane is 8nm. What is the Young’s modulus of erythrocyte membrane?

56MPa

Human exposure during radioscopy ( by X-ray) is 20R. Express this dose with unit of MeV/cm3.

142 · 104MeV/cm3

What is the character of blood flow within arterioles and near the heart valves?

It is laminar within arterioles, turbulent near the heart valves

During franclinization (electro-aerosol) procedure of a patient the electric charge of 1,6·10-2C passes between electrodes of electric machine during 10 minutes. Estimate average value of current.

2,66 · 10-5A

The focusing possibility of laser ray up to small diameters is caused by :

less divergence ;

What organ monitors movement and position of head?

vestibular system situated in the inner ear

Blood flow speed is maximum (r- is the radius of the blood vessel)?

in the centre of blood vessel;

The physiotherapeutic galvanization method is based on the action of:

direct current onto human body;

Daily acceptable absorption dose of ionized radiation for human beings is 0,017R. Determine the power of this radiation for 5 hours working day.

1mcR/s

Larmor frequency of MRI are

43-170MHz

What is the actual membrane potential of erythrocytes in vivo?

-9mV

What contraction is said to be isotonic contraction?

when the muscle does shorten but the tension on the muscle remains constant through the contraction

What answer is correct for elasticity behavior of materials?

steel elasticity occur in most crystal materials, rubber elasticity is typical for macromolecular materials

Clinically measurement method of the blood viscosity is:

Hess viscometer

Relation between linear velocity v and pulsing velocity vp is evaluated by α parameter. Point the formula of α :

α = r√ωρ/η

Between which physical states of a membrane there are phase transitions?

gel and liquid - crystal

In diagnostics of what diseases functional magnetic resonance Imagining (fRMI) is being conducted to use?

fMRI is an early diagnostic tool to detect neurological diseases such as Alzheimer’s, Parkinson’s, Huntington’s.

Point the Nernst- Equation: Where Δψ-is electrical potential difference across the membrane, aA II and aAI are ions activities in two phases

Δψ=(ψI-ψII) =(RT/zAF) ×ln(aAII/aAI)

Fahraeus-Lindqvist effect in the large vessels leads

The erythrocytes to concentrate in regions of minimal shear stress, namely in the center of the vessel

What is a PET (positron emission tomography) scan scanused to diagnose?

positron emission tomography(PET) scans detect early signs of cancer, heart diseases and brain disorders.

Point the electrochemical potential:

µi ˜=µi+ziFψ

What magnetic field is utilized in MRI?

1-4T

Resolution of MRI and CT scan diagnostic methods

in MRI-0,5mm of soft tissue, in CT scan 2mm of soft tissue

What does the elastic limit represent?

reversible deformation up to given elastic limit

What force of muscle is required due to held the object of 5kg depicted in the picture (g=10m/sec2)( gravitational force of which is applied to center of mass of elbow is negligible. R is gravitational force which is applied to held object , F is contraction force of elbow. a=4cm and b=28cm are corresponding arms of forces F and R.

350N

The resting potential of the cell membrane approximately U = -80 mV. If consider, the electric field strength is homogeneous in the inner of the membrane, find the intensity of this field. The thickness of the membrane is l = 8 nm.

107 V/m

The hydraulic resistance of the vessel deped on

the radius of the vessel

What ability of living cells is examined by electric field due to vibrating probe method ?

Growing ability

By what equation the hydraulic resistance is calculated?

R = 8ηl / πr4

Show the main ions which create the resting potential:

K+, Na+, Cl

100

What is the formula of Young`s modulus ?

Y = σ / ε

Dr.Fatimə Hüseynova Alman Dili sualları 1-50

samnet net · 50問 · 2年前

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