Exam 4: Principles of Neural and Hormonal Communication

With presynaptic inhibition,

Choose the match for each substance listed. a.covering on the axon b.second messenger c.branching process from a cell body d.impulse-conducting region e.junction between neurons f.neurotransmitter -Myelin

A single nerve cell, also called a ____________________, typically consists of the following three basic parts: ____________________, ____________________, and ____________________.

When is a plasma membrane more permeable to K⁺ than to Na⁺?

Indicate the relationship between the two items listed in each situation: a.A is greater than b. b.B is greater than a. c.A and B are equal. -a.Resting neuron's permeability to K⁺ B.Neuron's permeability to K⁺ during the falling phase of an action potential

Neuron A is excitatory to neuron B.Describe three ways that the nervous system might prevent neuron B from experiencing an action potential.

Indicate the relationship between the two items listed in each situation: a.A is greater than b. b.B is greater than a. c.A and B are equal. -a.Resting membrane potential B.Potential during depolarization

In a second messenger system, the first messenger is the __________.

Lipophilic hormones bind to hormone response elements on DNA, which then initiates steps in the formation of new protein molecules.

Myelinated fibers throughout the nervous system can regenerate when cut, but unmyelinated fibers cannot regenerate.

Use this figure to answer the corresponding questions. -Describe an action potential and explain why a region of the membrane that is in the absolute refractory period cannot experience another action potential until repolarization is complete.Include the following in your answer: voltage-gated Na⁺ channels, voltage-gated K⁺ channels, activation gate, inactivation gate, threshold voltage, increasing membrane potential, and decreasing membrane potential.

Which of the following is least related to a description of contiguous conduction on a neuron?

A single neuron may be presynaptic to one group of neurons and postsynaptic to another group of neurons.

Indicate whether the membrane is more permeable to K⁺ or to Na⁺ or is equally permeable to these ions under the stated conditions: a.more permeable to K+ than to Na+ b.more permeable to Na+ than to K+ c.equally permeable to Na+ and K+ -During an EPSP

Indicate the relationship between the two items listed in each situation: a.A is greater than b. b.B is greater than a. c.A and B are equal. -a.Neuron's permeability to Na⁺ during the rising phase of an action potential B.Neuron's permeability to K⁺ during the rising phase of an action potential

When comparing saltatory conduction to contiguous conduction, saltatory conduction

When EPSPs originating from a single presynaptic input occur so close together in time that they add together or sum, thereby bringing the postsynaptic cell to threshold, it is called ____________________ summation.

Indicate whether an excitatory or inhibitory synapse is being described. a.excitatory synapse b.inhibitory synapse -Increased PK₊ of the subsynaptic membrane (no change in PNₐ₊)

If neuron X causes hyperpolarization of neuron Z but neuron Y causes depolarization of neuron Z, what change would you expect in neuron Z if it is stimulated by both X and Y simultaneously?

Action potentials can be summed.