1st semester: Electrophysiology Flashcards
A stronger than 3 threshold stimulus intensity can initiate another action potential during the time when there is continued conductance to ______ creating a more negative potential than the RMP
potassium [this is true for REFRACTORY period]
To regulate the volume of cells in a hypotonic medium which of the following happens?
The osmolytes are transported _____
out of the cell to promote regulatory volume decrease
Rate of diffusion is faster in/for gases like
O2 and CO2
simple diffusion is under
passive diffusion
Lighly touching one’s skin with a pen will result to?
change in the membrane potential depending on the stimulus intensity
What cell structure is the site of LIPID and STEROID synthesis?
SER (smooth endoplasmic reticulum)
True about action potential:
Action is inevitable
Follows all or none principle
It is propagated with the same size and shape along the length of the axon
This change from RMP occurs when the membrane potential becomes less negative approaching zero mV
Depolarization
The resting membrane potential in a NEURON is -70mV because
the Na-K pump activity provides additional loss of positive charges in the cell
It is the membrane potential wherein an action potential is inevitable
Threshold potential
It is NOT a characteristic of an ion channel:
Saturation kinetics
During the repolarization phase, there is an increase in
potassium efflux
what type of transport process is involve when sodium is transported into the cell in exchange for calcium?
secondary active transport
which of the following statements is a characteristic of a graded potential?
It can undergo summation
A state in which a stronger than the threshold stimulus is required to trigger another action potential
Relative refractory period
Na-Glucose symporter exemplifies what class of membrane transport protein?
Solute carrier
I. RMP of nerve fiber: -70mV
II. stimulus applied which brought the membrane potential to -50mV
What happens next?
Influx of sodium into the nerve fiber
The following are the factors that increase the rate of diffusion across the cell membrane EXCEPT:
High viscosity medium
A semi permeable membrane (selectively permeable to water and less permeable to NaCl) is placed between Solution A containing 150mm’L of NaCL and solution B containing 300 mmol/L of NaCl. What is th expected finding in this experiment?
There will be movement of water from Solution B to A.
The driving force for movement of water between the ECF and the ICF is
Osmotic pressure gradient
The sound waves heard by our ears first activate which channels?
Mechanically gated channels
This is the potential difference generated across membrane because of a concentration difference of an ion
Diffusion potential
The transport of water across the membrane required which transport protein?
Aquaporins
Which of the following chemical composition forms the cytoskeleton of the cellular organelles?
proteins
