Chapter 12 Connect

which numerical value is most likely to be the resting membrane potential of a neuron?

-70 mV

indicate the order of events that are initiated in an adrenergic synapse, after norepinephrine binds to its receptor.

1. G protein dissociates from receptor protein 2. G protein binds to adenylate cyclase 3. adenylate cyclase is activated 4. ATP is converted to cyclic AMP by adenylate cyclase 5. cyclic AMP induces multiple effects in the cell

which of the following statements are true about sodium?

1. Na+ is about 12 times as concentrated in the ECF as in the ICF 2. the resting plasma membrane is much less permeable to Na+ than to K+

the visceral motor division of the PNS is also called the autonomic division. which of the following are functions of this division?

1. accelerating or decreasing heartbeat 2. controlling gland secretion 3. stimulating or inhibiting digestion

which statements are true about this type of conduction (this picture illustrates signal conduction along myelinated fibers)?

1. action potentials occur only at the nodes of Ranvier 2. there are few voltage-gated ion channels at the myelin-covered internodes and multiple channels at the nodes of Ranvier 3. ions can be exchanged with the ECF only at the nodes of Ranvier

match the following terms with their description.

1. axon hillock: a mound located on one side of the soma from which the axon originates 2. axoplasm: cytoplasm of the axon 3. axolemma: plasma membrane of the axon 4. axon collateral: branch that originates from an axon

list in chronological order the stages of regeneration of a nerve fiber.

1. degeneration of axon and myelin distal to injury 2. swelling of soma; dispersal of Nissl bodies 3. sprouting of axon growth processes 4. growth process enters regeneration tube 5. reestablishment of synaptic contact

the nervous system plays an important role in maintaining homeostasis. list, in order, the basic steps that describe how the nervous system carries out this task.

1. information received by sensory receptors is transmitted to the CNS 2. information is processes and an appropriate response is determined 3. a command is issued to effectors such as muscles or glands

place these events into the order in which they occur during a single action potential.

1. local potential depolarizes membrane 2. threshold is reached 3. depolarization spike 4. repolarization 5. hyperpolarization

starting with a signal reaching the distal end of the presynaptic axon, indicate the correct order of events that occur during transmission at a cholinergic excitory synapse.

1. opening of calcium gates in synaptic knob as nerve signal arrives 2. exocytosis of ACh; diffusion across synaptic cleft 3. binding of ACh to receptors on postsynaptic neuron 4. opening of sodium gates on post-synaptic membrane allowing influx of sodium 5. depolarization of postsynaptic plasma membrane

match each point in the action potential to the corresponding description of voltage-gated sodium and potassium channel activity.

1. resting membrane potential: both types of voltage-gated channels are closed 2. depolarization begins: voltage-gated Na+ channels open; voltage-gated K+ channels open more slowly 3. repolarization begins: voltage-gated Na+ channels inactivate; voltage-gated K+ channels remain open longer

which would cause postsynaptic stimulation to end?

1. reuptake of neurotransmitter into the presynaptic knob 2. diffusion of neurotransmitter from the synaptic cleft into extracellular fluid 3. cessation of signals in the presynaptic nerve fiber 4. enzymatic degradation of neurotransmitter in the synaptic cleft

match each glial cell type with its location and function.

1. satellite cells: in the PNS; surround somas of neurons in the ganglia, provide chemical insulation, and regulate the chemical environment of neurons 2. schwann cells: in the PNS; form neurilemma around all PNS fibers and myelin around most of them; aid in regeneration of damaged nerve fibers 3. ependymal cells: in the CNS; line cavitie of the brain and spinal cord; secrete and circulate CSF 4. microglia: in the CNS; phagocytize microorganisms, foreign matter, and dead nervous tissue

which statements are true regarding postsynaptic potentials?

1. they are caused by neurotransmitters 2. they include EPSPs and IPSPs 3. they are changes in the membrane potential of the postsynaptic terminal of a chemical synapse

which are characteristics of neural pools?

1. they consist of complex patterns of interneurons 2. they may be concerned with a particular body function

which are true about action potentials?

1. they do not get weaker with distance 2. they are "all-or-none" 3. once a neuron goes to threshold, the action potential usually cannot be stopped once it has begun

which statements are true about schwann cells?

1. they form the neurilemma 2. they form the myelin sheath in the PNS 3. they assist in the regeneration of damaged nerve fibers

indicate which of the following statements are true about this type of conduction (the picture illustrates signal conduction along unmyelinated fibers)

1. unmyelinated fibers have voltage-gated channels along their entire length 2. a zone of depolarization excites voltage-gated channels immediately distal to the action potential

categorize the six kinds of neuroglia to whether they are found in the CNS or in the PNS

CNS: astrocytes, ependymal cells, microglia, oligodendrocytes PNS: satellite cells, Schwann cells

which best decribes an electrical potential?

a form of potential energy that can produce current

which best describes signal conduction in unmyelinated axons?

a wave of depolarization opens more voltage-gated channels immediately distal to the action potential

neurons that convey information to the CNS are called sensory neurons, or ________ neurons.

afferent

select the four categories of neurotransmitters based on chemical composition.

amino acids, acetylcholine, neuropeptides, monoamines

neurons that have multiple dendrites but no axons, and which do not produce action potentials, are called ___________ neurons.

anaxonic

name the long neuronal process that generally conducts impulses away from the soma of the nerve cell.

axon

what are the two major anatomical subdivisions of the nervous system?

central and peripheral nervous systems

the nervous system must interpret quantitative and qualitative information about its environment, this it converts information to a meaningful pattern of action potentials. this process is called neural _____.

coding

which fundamental physiological property of neurons allows them to send signals quickly over long distances?

conductivity

which term refers to the flow of charged particle from one point to another?

current

the processes that branch from the somas of most neurons are called _________.

dendrites

motor, or ______, neurons carry signals away from the CNS and they lead to effectors (muscle and gland cells).

efferent

two organ systems are dedicated to interna coordination, communication between the other systems, and maintaining the overall homeostasis of the body. they are the _______ system, which communicates by means of hormones, and the _______ system which sends quick electrical and chemical messages from cell to cell.

endocrine; nervous

the knotlike swelling in a nerve where neuron cell bodies are found is called a(n)...

ganglion

________ cells protect the neurons and help them function.

glial

what are characteristics of local potentials?

graded, decremental

the opposite of facilitation is presynaptic _____________. This is a mechanism in which one presynaptic neuron suppresses another one.

inhibition

list the three functional classes of neurons.

interneurons, sensory neurons, motor neurons

what creates electrical currents in neurons?

movement of ions through channels

neurons are classified structurally according to the number of processes extending from the soma. match each classification to its description.

multipolar neurons: one axon, multiple dendrites bipolar neurons: one axon, one dendrite unipolar neurons: a single process anaxonic neurons: no axon, multiple dendrites

taken together, the sensory and motor subdivisions make up which of the following?

peripheral nervous system

at a synapse, the neuron that responds to the neurotransmitter is the ________ neuron.

postsynaptic

in a chemical synapse, synaptic vesicles full of neurotransmitter are docked at release sites on the membrane of the presynaptic neuron, while neurotransmitter receptors are found on the membrane of the ________ neuron.

postsynaptic

which ion has the greatest influence on the resting membrane potential of most neurons?

potassium

which of the following are types of long-term memory?

procedural, declarative

firing additional neurons as a stimulus becomes stronger is an example of which of the following?

recruitment

propogation of an action potential down a myelinated axon in which the action potential appears to "jump" from node to node is called ___________ conduction.

saltatory

which of the following terms refers to the part of the PNS that carries signals from various receptors to the CNS?

sensory division

there are two ways in which EPSPs can add up to produce enough activity to make a postsynaptic cell fire: temporal and spatial ________.

summation

the autonomic nervous system is subdivided into the __________ division which tends to arouse the body for action and the __________ division which tends to have a calming effect.

sympathetic; parasympathetic

this picture shows a single synapse generating EPSPs so quickly that each is generated before the previous one fades. what is this process called?

temporal summation

what is the resting membrane potential (RMP) of a neuron?

the electrical potential (voltage) across the plasma membrane at rest

neurons with a single process extending from the soma, such as the neurons that carry sensory signals to the spinal cord, are classified structurally as ___________ neurons.

unipolar