Nervous system : Nervous Tissue

when the inactivation gate of a voltage gated sodium channel closes the activation gate is ___

open

sensory and motor nerves are part of the ___ nervous system

peripheral

the picture depicts the process of myelination in the __ nervous system

peripheral

which of the following are functions of astrocytes

regulates the composition of interstitial fluid replaces damaged neurons helps form the blood brain barrier

match the states of the sodium channel with their correct descriptions

resting - entry of sodium is prevented, activation gate is close activation- sodium moves into the cell through the open channel inactivation- entry of sodium is prevented activation gate is open

which of the following membrane transporters are present throughout the membrane of a neuron?

sodium leak channels Na+ K+ pumps potassium leak channels

t or F in saltatory conduction, Na+ only flow across the axon membrane at the neurofibril nodes

t

voltage gated calcium channels are found mostly in the ___ segment

transmissive

t or F facilitation and inhibition may be caused by changes in either the presynaptic neuron or the postsynaptic neuron

true

the voltage gated sodium channels undergo changes in activity during the depolarization phases of an action potential. place these in order from first to last

1. a graded potential depolarizes the intital segment 2. voltage gated sodium channels open 3. sodium flows into the neuron at the initial segment 4. further depolarization of the initial segment occurs 5. sodium channels enter the inactive state

place the events of synaptic transmission from earliest to latest

1. action potential reaches synaptic knob 2. voltage gated calcium channels open 3. calcium enters the synaptic knob 4. calcium triggers exocytosis of vesicles 5. neurotransmitter diffuses across synaptic cleft 6. neurotransmitter binds to postsynaptic receptors

T or F ion channels use the energy of ATP to maintain concentration gradients across neuron membranes

F

T or F ion channels use the energy to ATP to maintain concentration gradients across neuron membranes

F

which of the following ions have leak channels on the plasma membrane

Na+ K+

which of the following pumps can you find the plasma membrane

Na+/K+ Ca2+

match the time periods indicated by the arrows with their descriptions

a- absoulte refractory period b- relative refractory period ( has loop)

in which direction does fast axonal transport occur

anterograde and retrograde

which of the following statements correctly describes the role of k+ leak on the resting membrane potential

as potassium flows out of a cell the inside of the cell becomes more negative

which functional division of the nervous system controls involuntary movement of smooth muscle?

autonomic motor nervous system

the plasma membrane of an axon is called the

axolemma

the axon hilcock connects the ___ to the soma

axon

a synapse us a junction

between a neuron and another cell

synapses are classified as

chemical synapses electrical

which of the following is best described as a channel that is usually closed that open in response to binding a neurotransmitter and that when open, allow a specific type of ion to diffuse across the plasma memebrane

chemically gated channel

which of the following are among the general characteristics of graded potential

decrease intensity with distance traveled along membrane can either be depolarizing or hyperpolarizing degree of change in membrane potential is dependent of the stimulus magnitude

acetylchollnesterase removes from the synaptic cleft via

degradation

___ occurs when the inside of the cell becomes more positive than the resting membrane potential

depolarization

which of the following processes are occuring during the synaptic delay

diffusion of neurotransmitter binding of neurotransmitter to receptors release of neurotransmitter

tissue that respond to neural input by changing its activity is called

effector

the net diffusion of a given ions is dependent ipon its

electrochemical gradient

the e in EPSP stands for ___ meaning that the potential makes the inside of the postsynaptic cell more ___

excitatory positive

place the events of an EPSP in order

excitatory neurotransmitter binds to receptor Na+ channel Na+ enter the postsynaptic cell the inside of the cell becomes more positive the local current of Na+ becomes weaker as it moves toward the axon hilcock

when chemically or voltage gated channels open, there is a change in ion ___ across a membrane

flow

a cluster of neuron cell bodies found along a peripheral nerve is known as

ganglia

synapses occur where axons contat

gland cells muscle cells other neurons

match the neurotransmitter with its class

glutanate- amino acid norepinephrine- monoamine neuropeptide- sommatostatin

negatively charged proteins and other large organic molecules are found in

greater amounts inside a neuron

___ occurs when the inside of a cell becomes more negative than the resting membrane potential

hyperpolarization

the electrical gradient in a resting neuron is such that the ___ of the cell is negative relative to the ___

inside outside

PSPs are considered graded potentials because the more tranmitter is released the ___ the PSP

larger

which of the following is used for fast axonal transport

microtubules motor proteins ATP

which of the following conditions can make a PSP larger

more transmitter is releases more postsynaptic channels open

the autonomic division of the nervous system is part of the ___ nervous system

motor

interneurons facilitate communication between __ neurons and ___ neurons

motor sensory

match the structure with the appropriate letter

a- olgodenocyte b- axons c- nucleus d- mylein sheath

the components of the somatic division are

hearing joints and muscle taste

place the events of chloride based IPSP in order from earliest to latest

inhibitory neurotransmitter binds to postsynaptic chemically gated chloride channels 2. chloride moves from outside the cell to the inside 3. the inside of the postsynaptic cell becomes more negative 4. the local chloride current becomes weaker as it moves toward the axon hilock

choose which of the following can be the mechanism by which neurotoxins may do harm

interfere with transmission of action potentials induce detrimental structural change to a neuron after events that occur at a synapse

the autonomic nervous system is also known as the

involuntary nervous system

if you were moving across a neuron's membrane from the receptive segment toward the transmissive segment, where would you first encounter large numbers of voltage gates Na+ and K+ channels?

the initial segment

which of the following sgments of a neuron contains large numbers of voltage gates potassium channels and voltage gated sodium channels

the initial segment the conductive system

what must happen in order for a chemical signal to change the membrane potential of a neuron?

there must be a change in the name of open ion channels there must be a change in ion flow across the membrane

which of the following are true of neurolemmocytes?

they create the myelin sheath in the PNS they are also called Schwann cells