Neurophysiology 1-2: Excitable Cells and Electric Currents

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What is the primary function of motor neurons?

Processing information in the central nervous system

Sending signals from the central nervous system to the effector organs (correct)

Sending signals from sensory receptors to the central nervous system

Generating electrical current across the membrane

What is the resting membrane potential of a typical neuron?

-40 mV

-70 mV (correct)

-90 mV

0 mV

Which type of cells are capable of generating an electric current across the membrane?

Excitable cells (correct)

Red blood cells

Non-excitable cells

Endothelial cells

Which cells have a resting membrane potential of -8 mV?

Red blood cells Signup and view all the answers

What is the significance of the differential distribution of charged particles across the membrane in excitable cells?

It allows for intracellular communication Signup and view all the answers

Which type of muscle cells are examples of excitable cells?

All of the above Signup and view all the answers

What determines the effect of each synapse on a neuron's likelihood of producing an action potential?

Location of the synapse and timing of the postsynaptic potentials Signup and view all the answers

What is the term for the effect of location on the effect of a postsynaptic potential?

Special summation Signup and view all the answers

What is the term for the effect of timing on postsynaptic potential effect?

Temporal summation Signup and view all the answers

What happens when the membrane potential at the axon hillock reaches the threshold value?

An action potential is produced Signup and view all the answers

How do action potentials differ from postsynaptic potentials in terms of amplitude changes?

Action potentials produce larger amplitude changes than PSPs Signup and view all the answers

Where are postsynaptic potentials produced?

Dendrites, and sometimes cell body or axon Signup and view all the answers

What is the result of an action potential?

Release of neurotransmitter from the axon terminal Signup and view all the answers

What ensures one-way propagation of action potentials from the axon hillock to the axon terminus?

Refractory period of sodium channels Signup and view all the answers

Which type of molecules can diffuse right through the phospholipid bilayer?

Gasses like carbon dioxide and oxygen Signup and view all the answers

What is the role of aquaporins in cell membranes?

Permitting water to cross the cell membrane Signup and view all the answers

Which process does not require energy and always follows a concentration gradient?

Facilitated diffusion Signup and view all the answers

What is the primary function of ion pumps in cell membranes?

Move ions against their concentration gradient using ATP Signup and view all the answers

What is the significance of the sodium-potassium pump in excitable cells?

It is important in generation and maintenance of the resting membrane potential Signup and view all the answers

What is the role of leak channels in cell membranes?

Permit constant flow of ions Signup and view all the answers

What happens when a sodium channel opens in a healthy animal cell?

There will be net movement of sodium ions into the cell Signup and view all the answers

Which part of a neuron carries an electrical signal to a synapse and converts it to a chemical signal?

The axon Signup and view all the answers

What are the two types of postsynaptic potentials that can occur in response to neurotransmitter binding?

Excitatory postsynaptic potentials and inhibitory postsynaptic potentials Signup and view all the answers

Where are voltage gated ion channels located?

Axon hillock Signup and view all the answers

What happens if the summation of postsynaptic potentials reaches the threshold level?

Voltage gated channels will be activated and an action potential will result Signup and view all the answers

What is the role of axon hillock in a neuron?

Site where all postsynaptic potentials are added together Signup and view all the answers