Exam 4: Principles of Neural and Hormonal Communication

MATCHING Indicate the direction that the force in question tends to move the involved ion under the stated conditions by writing the appropriate letter in the blank, using the following answer code: -concentration gradient for K⁺ at the peak of an action potential

The falling phase of the action potential is due to

MATCHING Indicate the direction that the force in question tends to move the involved ion under the stated conditions by writing the appropriate letter in the blank, using the following answer code: -concentration gradient for Na⁺ at the end of an action potential

The following question refers to comparative concentrations, permeabilities, and potentials under various circumstances. Indicate the relationship between the two items listed in each situation by filling the appropriate letter in the blank using the following answer code: -A. concentration of K⁺ in the intracellular fluid of a nerve cell immediately before an action potential B. concentration of K⁺ in the intracellular fluid of a nerve cell immediately following an action potential (assume that the Na⁺-K⁺ pump has not yet acted)

Which of the following is not associated with the postreceptor events of hydrophilic hormones?

The nervous system exerts considerable control over the endocrine system, but hormones have no influence over the nervous system.

MATCHING: ART The following questions refer to the accompanying diagram of an action potential. Segments of the action potential are labeled A-D. Match the letters to the corresponding statements below. -After hyperpolarization phase

A neurotransmitter may be excitatory at one synapse and inhibitory at another.

The junction between two neurons is known as a(n) ____________________.

Compare and contrast the receptor and postreceptor events for lipophilic and hydrophilic hormones.

A neuron fires an impulse by the all-or-____________________ law.

Indicate whether an excitatory or inhibitory synapse is being described by filling in the blank using the following answer code: -a small hyperpolarization of the postsynaptic neuron

A given synapse is always excitatory or ____________________.

Indicate which characteristic applies to classical neurotransmitters and neuropeptides using the following answer code: -released from axon terminal

A threshold potential is

When chemically-gated Na⁺ channels open

The relative refractory period occurs after the action potential is complete because of the

Use the answer code to answer the questions in this section: -Ion movement responsible for the rising phase of the action potential.

The following question refers to comparative concentrations, permeabilities, and potentials under various circumstances. Indicate the relationship between the two items listed in each situation by filling the appropriate letter in the blank using the following answer code: -A. membrane potential at rest B. the potential of the same membrane when it is depolarized

The ____________________ or ____________________ of a nerve cell is a single, elongated tubular process that conducts action potentials away from the cell body and eventually terminates at other cells.