BIOL 115 Lecture Notes - Lecture 20: Electrophysiology, Cochlea, Nucleus Accumbens

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jadebat19

21 Nov 2017

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Neurons send signals using the highly controlled movement of ions along their concentration and electrical gradient. Ions pass through specialized channels in the membrane. Specialized for particular ions and directions (in or out) Channels are proteins that open and close based on the voltage. Energy is used to return the system back to where it started (atp) If you have a little action potential, it moves along the axon. There is either an action potential or there is not. The connection between the terminal of one cell and the dendrite on the next cell. At the synapse, the electrochemical wave or action potential is converted into a chemical signal. This chemical signal is released by the terminal of the sending cell. There are many kinds of neurotransmitters and neuroactive substances. They can affect the probability and timing of action potentials. How much input will be needed to fire. When the cell will fire relative to that input.

Related Questions

1.A stronger stimulus to a neuron results in ________.

A. larger voltage changes in graded potentials and greater frequency of action potentials produced in response

B. greater frequency of graded potentials and larger voltage changes in the action potentials produced in response

C. larger voltage changes in the graded potentials, but no changes in action potentials

D. larger voltage changes in both graded and action potentials

E. larger voltage changes in graded potentials but smaller action potentials

2. Why is it more difficult to fire an action potential when the interval between stimuli decreases?

A. because sodium is flowing out of the cell

B. because potassium is flowing into the cell

C. because some sodium channels may still be in an inactivated state

D. because chloride is flowing into the cell

E. because chloride is flowing out of the cell

3. As an action potential zips down an axon,

A. voltage gated potassium channels open first followed by voltage-dependent sodium channels

B. voltage- gated sodium channels ahead of the wave and not yet activated are influenced by the depolarizing electrical field of other nearby sodium channels

C. voltage-gated potassium channels ahead of the wave and not yet activated are influenced by the depolarizing electrical field of nearby sodium channels

D. leak channels are opened by the wave of electricity passing along the axon

E. B and C

Which of the following statements is FALSE? (choose one)

A.	Voltage-gated sodium (Na+) channels open in the dendrites and cell body during a local, graded potential.

B.	During repolarization, potassium ions are leaving the cell (K+ is diffusing out of the cell), and the inside of the cell becomes more negative

C.	If someone damaged an efferent motor neuron, they could feel pain, but not respond to move away from the pain

D.	Myelin serves as electrical insulation and increases the speed at which an action potential travels along the axon

E.	Movement of ions can be excitatory (if sodium ligand-gated channels bind the neurotransmitter), or inhibitory (if potassium ligand-gated channels bind the neurotransmitter)

From the following list, select all options that are correctwith respect to the synapse.

Question 5 options:

A)	the synapse is the site where the plasma membrane that coversthe axon terminal of one neuron makes direct contact with and fusesto the plasma membrane on the cell body or dendrite of anotherneuron

B)	the action potential travels through extracellular fluid in thesynapse to get from one neuron to the next

C)	presynaptic nerve terminals release chemical messengers into thesynapse in response to arrival of an action potential

D)	signaling molecules in the synapse can be broken down by enzymesthat are present on the post synaptic cell membrane

E)	signaling molecules in the synapse can bind to 're-uptake'receptors and be taken back into the presynaptic neuron forbreakdown or for repackaging/reuse

F)	signaling molecules can be taken into and degraded within thepostsynaptic cell

G)	signaling molecules in the synapse function as chemicalmessengers that regulate the opening of ligand-gated channels inthe plasma membranes of post synaptic cells

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BIOL 115 Lecture Notes - Lecture 20: Electrophysiology, Cochlea, Nucleus Accumbens

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