week 3 LAB studyguide

The line on the computer screen during the resting membrane potential simulation represents the ________ of the membrane potential

Voltage

Resting membrane potential is the _______ difference across the plasma membrane

Electrical

Resting membrane potential is measured in units called

Millivolts (mV)

A resting membrane potential of -70mV means the inside of the cell is more ______ than the outside

Negative

Resting membrane potential is caused by an unequal distribution of charged _____ across the membrane

Ions

Resting membrane potential is found across the plasma membrane of the cell including the cell body, dendrites and

Axon

Increasing the concentration of potassium outside the cell makes the membrane potential become less negative or more

Less negative

Potassium generally has a _____ effect on resting membrane potential than sodium

Greater

A 10-fold increase in extracellular sodium changes membrane potential by about ______ mV

+5 mV

A 10-fold increase in extracellular potassium changes membrane potential by about ______ mV

+60 mV

Because potassium has a greater effect on resting membrane potential the membrane at rest is more permeable to _______ than sodium

Potassium

Leakage channels are typically ____ open

Always

Sodium ions diffuse through sodium leakage channels _____ the cell

Into

Potassium ions diffuse through potassium leakage channels ____ of the cell

Out of

Both sodium and potassium move through leakage channels _____ their concentration gradients

Down

Leakage channels do not require ____ to allow ion movement

Energy

A ______ potential occurs when ligand gated channels open and ions move through the membrane

Graded

Graded potentials are produced in the _____ segment of a neuron

Receptive

Graded potentials are typically cause by opening of _______ gated channels

Ligand

Graded potentials can vary in ______ depending on stimulus strength

Amplitude

Action potentials are initiated at the ___ hilock

Axon

The axon hillock is also called the neurons ____ zone

Trigger

Once threshold is reached at the axon hillock an ______ potential is generated

Action

Action potentials travel down the _____ of the neuron

Axon

In the lab experiment, Ringers solution was used as the _____ value for ion concentration comparisons

Baseline

Ringers solution is also useful for helping keep tissue from drying out but that is not its primary _____ in the experiment

Purpose

When the microelectrode tip is placed inside a muscle fiber the line on the computer screen represents the ____ potential

Membrane

When the electrode enters the inside of the muscle fiber the line on the screen should move _____

Downward

The crayfish muscle experiment was used to help visualize ____ potential changes

Membrane

The inside of a resting cell is more _____ than the outside

Negative

Potassium has a major role in establishing the _____ membrane potential

Resting

Sodium has less effect on resting membrane potential because the membrane is less permeable to ______ at rest

Sodium

The movement of ions through ligand gated channels helps produce ____ potentials

Graded

The movement of ions through voltage gates channels helps produce _____ potentials

Action