1. Which of the following is not a function of the nervous system? |
d. All are functions of the nervous system |
2. The peripheral nervous system can be divided into: |
d. All of the above |
3. The motor portion of the autonomic nervous system can be divided into: |
d. Sympathetic and parasympathetic divisions. |
4. This has the property of electrical excitability. |
c. All of the above |
5. A site of protein synthesis in a neuron: |
c. Nissl body |
6. Nerve fiber refers to: |
d. Both a and b |
7. This type of neuron has one main dendrite and one main axon. |
b. Bipolar neuron |
8. Myelin sheaths around axons are initially formed by Schwann’s cells |
b. During fetal development |
9. This contains neuronal cell bodies, dendrites, unmyelinated axons, axon terminals and neuroglia. |
a. Gray matter |
10. Which of the following is not a type of channel used in production of electrical signals in neurons? |
e. Ion-gated channel |
11. The resting membrane potential in neurons ranges from: |
c. -40 to -90 mV |
12. A polarized cell |
e. All of the above |
13. Na+/K+-ATPases are considered to be electrogenic pumps because |
a. They contribute to the negativity of the resting membrane potential |
14. A depolarizing graded potential |
b. Makes the membrane less polarized |
15. When a depolarizing graded potential makes the axon membrane depolarize to threshold |
d. Voltage gated Na+ channels open rapidly |
16. During the resting state of a voltage-gated Na+ channel |
d. Both a and b |
17. During which period can a second action potential be initiated by a larger than normal stimulus? |
c. Relative refractory period |
18. Saltatory conduction |
e. None of the above |
19. Which axons have the largest diameter? |
a. A fibers |
20. What phenomenon explains why a light touch feels different than a touch applied with more pressure? |
c. Frequency of impulses |
21. Which of the following terms describes synapses? |
e. All of the above |
22. Faster communication and synchronization are two advantages of |
b. Electrical synapses |
23. If a neurotransmitter depolarizes the postsynaptic membrane it is referred to as: |
a. Excitatory |
24. IPSP stands for: |
c. Inhibitory postsynaptic potential |
25. Diffusion, enzymatic degradation, and uptake by cells are all ways to |
a. Remove a neurotransmitter |
26. When the summed total of postsynaptic potentials rises above threshold, creation of action potentials occurs: |
c. At the trigger zone |
27. A postsynaptic neuron responds to neurotransmitters released by a presynaptic neuron by creating: |
e. All of the above |
28. Which of the following is not considered a small molecule neurotransmitter? |
d. Endorphins |
29. This neural circuit consists of a single presynaptic neuron synapsing with several postsynaptic neurons. |
a. Diverging circuit |
30. Plasticity means |
d. Capability to change based on experience |
31. What factors limit neurogensis? |
Ans: Inhibitory influences from neuroglia, mainly from oligodendrites and the absence of growth stimulating cues present during fetal development. Level: medium Link: 12.8 |
32. Describe four ways drugs can modify the effects of neurotrasmitters. |
Ans: Drugs can modify neurotransmitter effects by stimulating or inhibiting their synthesis, enhancing or blocking their release, activating or blocking their receptor, and stimulating or inhibiting their removal. Level: hard Link: 12.6 |
33. Describe the three ways neurotransmitters can be removed. |
Ans: Neurotransmitters can be removed by diffusion, enzymatic degradation or uptake by cells. Level: easy Link: 12.6 |
34. Describe the two conditions that allow maintenance of the resting membrane potential in excitable cells. |
Ans: Unequal distribution of ions across the plasma membrane and the relative permeability of the plasma membrane to Na+ and K+ help maintain the resting membrane potential. Level: easy Link: 12.4 |
35. Briefly describe what causes the depolarizing phase. |
Ans: Voltage gated Na+ channels open rapidly then both the electrical and chemical gradients favor the inward movement of Na+. The inward rush of Na+ causes depolarization phase of the action potential. Level: medium Link: 12.4 |
Refer to image 1 36. Which part of the diagram is considered nerve fiber? a. A |
e. All of the above |
Refer to image 1 37. This part of the neuron contains the nucleu and Nissl bodies. |
b. B |
Refer to image 1 38. This part of a neuron contains cytoplasm and a myelin sheath wrapped around neurolemma. Ans: C |
c. E |
Refer to image 1 39. In the diagram, where is the axon collateral? |
a. C |
Refer to image 1 40. In the diagram where are axon terminals? |
c. H |
Refer to image 2 41. Which of the neurons is a touch receptor known as a Merkel disc? |
b. B |
Refer to image 2 42. Which of the neurons is the type used in detecting painful stimuli? |
d. D |
Refer to image 2 43. Which of the neurons is called a Meissner corpuscle or a corpuscle of touch? |
a. A |
Refer to image 3 44. This type of cell myelinates a single axon |
a. A |
Refer to image 3 45. This electrically insulates the axon of a neuron to increase the speed of nerve impulse conduction. |
e. E |
Refer to image 3 46. In the diagram where are the Nodes of Ranvier? |
b. B |
Refer to image 3 47. In the CNS, this is produced by oligodendrocytes. |
e. E |
Refer to image 4 48. Which of the following represents a ligand-gated channel? |
b. B |
Refer to image 4 49. Which of these types of channels is involved in leaking sodium and potassium ions across the membrane in order to establish the resting potential of a cell? |
a. A |
Refer to image 4 50. This type of channel opens randomly. |
a. A |
Refer to image 4 51. In the figure which one represents a converging circuit? |
b. B |
The following statements regarding action potentials are true…. |
2. refractory period is the time when the neuron cannot generate another action potential |
The brain stem consists of the medula, pons and midbrain? |
true |
The type of neuoglia cell which is responsible for myelinization in the central nervous system is the…. |
2. oligondendrocyte |
factors which increase the speed of propgation of the action potential include… |
4. 1,2 are correct |
which of the following are NOT part of the spinal reflex arc? |
1. cerebellum |
the nervous system….. |
5. all above are correct |
differences between graded potentials and action potentials include all of the following EXCEPT….. |
4. there may be hyperpolarization or depolarizing AP |
release of the neurotransmitter from a synaptic end bulb is dependent on the opening of ________________gated channels in the presynaptic neuron. |
1. voltage-gated calcium ions |
_____________gated channels participate in the generation and conduction of action potentials |
voltage |
what two cells are there in the nervous system? |
neurons and neuroglia cells |
the __________nervous system consists of the brain and spinal cord |
central nervous system |
most signals that stimulate muscles to contract and glands to secrete originate in the _________nervous system |
CNS |
what part of the nervous system deals with incoming sensory information and is the source of thoughts, emotions, and memories. |
CNS |
What are the two main subdivisions of the nervous system? |
central and peripheral |
the ________nervous system consists of all tissue outside the CNS |
peripheral |
components of the PNS consist of ___________, ________, ________, and _________. |
nerves, ganglia, enteric plexuses, and sensory receptors |
a __________ is a bundle of hundreds to thousands of axons plus associated CT and blood vessels that lies outside the brain and spinal cord |
nerve |
there are _______pairs of cranial nerves,and _______pairs of spinal nerves |
12, 31 |
_______are small masses of nervous tissue, consisting primarily of neuron cell bodies that are located outside the brain and spinal cord |
ganglia |
_______is closely associated with cranial and spinal nerves |
ganglia |
What three categories is the PNS divided into? |
somatic nervous system(SNS) and autonomic nervous system(ANS) and enteric nervous system(ENS) |
the somatic nervous system consists of ______that convey info from somatic receptors in the head to the CNS, and_____________that conduct impulses from the CNS to skeletal muscle only |
sensory neuorns motor neurons |
the SNS is voluntary/involuntary? |
voluntary |
the branch of medical science that deals with the normal functioning and disorders of the nervous system is called ____________. |
neurology |
name the 3 types of neurons |
1. sensory neurons 2. motor neurons 3. associative neurons |
The ANS conduct sensory neurons and motor neurons from the CNS to ________,______, and ________. |
smooth muscle, cardiac muscle, glands |
the ANS is voluntary/involuntary? |
involuntary |
The motor part of the ANS consists of what two branches? |
sympathetic division parasympathetic division |
___________division increases heartrate, fight or flight response while _________division slows down heart rate and rest and digest activities. |
sympathetic division parasympathetic division |
the _____nervous system is considered the brain of the gut, mainly in the GI tract |
enteric |
the ENS is voluntary/involunatry? |
involunatry |
what are the three main functions of the nervous system? |
sensory function integrative function motor function |
the _________ is the functional unit of the nervous system |
neuron |
a _______or nerve impulse is an electrical signal that propagates along the surface of the membrane of a neuron |
action potential |
neurons make up 50% mass of nervous system and ______ make up 50% of mass of nervous system but are smaller in size then. |
neurons neuroglia |
a __________ is any change in the environment that is strong enough to initiate an action potential. |
stimulus |
name the 3 parts of a neuron |
cell body axon dendtrites |
________ are the location of protein synthesis in a neuron |
nissl bodies |
a single axon of a neuron propagates nerve impusles toward _________,_______, or_________. |
another neuron muscle fiber gland cell |
in most neurons, nerve impusles arise at the _______and the _______, an area called the trigger zone. |
axon hillock, and initial segment |
the site of communication between two neurons, or between a neuron and an effector is called the ____________. |
synapse |
synaptic end bulbs contain many tiny membrane enclose sacs called __________ that store a chemical called _______ |
synaptic vesicles neurotransmitter |
___________axonal transport carries axoplasm in one direction only-from the cell body toward axon terminals. |
slow |
____________axonal transport moves materials in both directins-away and toward the cell body. |
fast |
_________axonal transport supplies new axoplasm to developing or regenerating axons and replenishes axoplasm in growing and mature axons. |
slow |
_________axonal transport uses proteins that function as motors to move materials along the surfaces of microtubules of the neurons cytoskeleton. |
fast |
________neruons usually have several dendrites and one axon. Most neurons in the brain and spinal cord are this type. |
multipolar neurons |
______neurons have one main dendrite and one axon. They are found in the retna of the eye, the ear, and olfactory area of the brain |
bipolar neurons |
_________have dendrites and one axon that are fused together to form a continuous process that emerges from the cell body. |
unipolar neurons |
What are the 3 functional classifications of neurons? |
sensory neurons motor neurons interneurons or association neurons |
________neurons convey action potentials away from the CNS to effectors in the PNS through cranial and spinal nerves. |
motor |
__________neurons convey action potentials from the axon into the CNS through cranial and spinal nerves. |
sensory |
_______neurons are mainly located within the CNS between sensory and motor neurons. they integrate incoming sensory information from sensory neurons and elecit a motor response. |
interneuorns or association neurons |
most sensory neurons are _______in structure |
unipolar |
motor neurons are _____in structure |
multipolar |
most association neurons are ________in structure |
multipolar |
________do not generate or propogate action potentials |
neuroglia |
________can multiply and divide in the mature nervous system |
neuroglia |
name the 4 neuroglia cells found in the CNS |
1. astrocytes 2. oligodendrocytes 3. microglia 4. epemdymal |
name the 2 neuroglia cells found in the PNS |
schwann and satellite cells |
____________cells are the largest and most numberous neuroglia cells. |
astrocytes |
__________neuroglia cells deal with the blood brain barrier |
astrocytes |
______________neuroglia cells are responsible for maintaining myelin sheath around CNS axons. |
oligodendrocytes |
_______neuroglia cells function as phagocytes |
microglia |
________neuroglia cells produce CSF |
ependymal |
______neuroglia cells encircle PNS axons; form myelin sheath. |
schwann |
______neuroglia cells surround cell bodies of neurons in the PNS ganglia and regulate intersitial fluid |
satellite |
axon surrpunded by a multilayered ______ and __________covering is called the myelin sheath |
lipid and protein |
What is the purpose of the myelin sheath? |
electrically insulates the axon of a neuron and increases speed of nerve impusle conduction. |
what two types of neuroglia cells produce myelin sheath? |
schwann(PNS) and oligodendrocytes(CNS) |
________cells begin to form myelin sheaths around axons during fetal development |
schwann |
_______are clusters of neuronal cell bodies in the PNS. __________ is a cluster of neuronal cell bodies located in the PNS |
gangliaon nucleus |
a _______is a bundle of axons in the PNS. A ______ is a bundle of axons that is located in the CNS. |
nerve tract |
_______interconnect neurons in the spinal cord and brain |
tract |
_________mater is composed primarily of myelinated axons. |
white |
__________mater contains neuronla cells bodies, dendrites, unmyelinated axons, axon terminals, and neuroglia. |
gray |
True/Fasle Blood vessels are found in both white and gray matter? |
true |
what two types of electrical signals do neurons communicate with? |
graded potentials and action potentials |
_________potentials are used for short distance, while __________potentials are long distance. |
graded potentials action potentials |
As you touch a pen, a_________ potential develops in a sensory receptor in the skin and fingers. The graded potential then triggers the axon of the sensory neuron to form a nerve ______potential, which travels along the axon into the ________nervous system and ultimatly causes release of __________ at the ________. The neurotransmitter stimulates the interneuron to form a ________potential in its ______ and _________. |
graded action CNS neurotransmitter synapse graded dendrites cell body |
the production of graded potentials and action potentials depends on two basic features. Name them. |
1. existence of resting membrane potential 2. presence of specific types of ion channels |
name the 4 types of ion channels |
1. voltage gated channels 2.leak channels 3. ligand-gated channels 4. mechanically gated channels |
typically, plasma membranes have many more ________leak channels then _________leak channels. |
potassium ion sodium ion |
a wide variety of chamical ligands such as ______,________, and__________ can open or closeligand-gated channels. |
neurotransmitter hormones particular ions |
_______gated channels opens in response to a change in membrane potential (voltage) |
voltage gated |
__________ are gated channels that randomly open and close |
leak channels |
Why does the resting membrane exist? |
a small buildup of negative ions in the cytosol along the inside of the membrnae and an equal buildup of positive ions in the extracellular fluid along the surface of the membrane. |
the separation of negative and positive charge during resting membrane potential creates _______energy. |
potential |
inneurons, the resting membrane potenital ranges from _____ to _____ mV |
-40 to -90 |
what does the minus sign in -70mV mean? |
the inside of the cell is negative relative to the outside |
a cell that exibits a resting membrane potential is said to be ___________. |
polarized |
Name the 3 major factors in which resting membrane potentials arise. |
1. unequal distribution of ions in the EFC and cytosol 2. inability of most anions to leave the cell 3. electrogenic nature of the Na+/K+ ATPases-membrane permeability to NA+ is very low because there are only a few sodium leak channels. |
a _______________ is a small deviation from the membrane potential that makes the membrane either more polarized or less polarized. |
graded potential |
what does hyperpolarizing mean? |
making the membrane more polarized (inside more negative) |
what does depolarizing mean? |
makeing the membrane less polarized (inside less negative) |
what is the typical value for the resting membrane potential of a neuron? |
-70mV |
graded potentials deal with ________gated channels |
ligand or chemically |
action potentials deal with _______gated channels |
voltage |
the amplitude of graded potentials vary depending on what? |
strength of the stimuli |
according to the all or none principle, if a stimulus is strong enough to generate an action potential, the impulse generated is a ______size. |
constant |
True/Fasle A stronger stimulous generates a larger action potential? |
false |
The grater the stimulus strength above threshold, the ________the frequency of the action potentials. |
greater |
during an action potential, voltage gated ______ and _______channels open and close in sequence. |
Na+ K+ |
during the first part of the refractory period, another impulse can/can not be generated? |
cannot |
when another impulse can not be generated is considered ________. when another impulse can be generated, but only by a larger then normal stimulus is _________. |
absolute RP relative RP |
nerve impulse propagation in which impulse "leaps" from one node of Ranvier to the next along a myelinated axon is called ______________. |
saltatory conduction |
__________conduction is faster then _________ conduction |
saltatory conduction continuous conduction |
True/False Axons with larger diameters conduct impulses at higher speeds than do axons with smaller diameters. |
True |
what does graded mean? |
varying in amplitude (size) |
what determines the amplitude of a graded potential? |
depends on how many ligand gated channels have opened (or closed) and how long each remains open. |
_________is the process by which graded potentials add together |
summation |
a ________ or impulse is a sequence of rapidly occurring events that decrease and reverse the membrane potential and then eventually restore it to the resting state. |
action potential |
what two main phases does and action potential have? |
repolarizing state depolarizing phase |
What occurs during the depolarizing phase of an action potential? |
the negative membrane potential becomes less negative, reaches 0, then becomes more positive |
What occurs during the repolarization phase of an action potential? |
the membrane potential temporarily becomes more negative then the resting level. |
what two types of voltage gated channels open and close during an action potential? |
open-voltage gated Na+ channels allow Na+ to rush into the cell which causes depolarization. open-voltage gated K+ channels allow K+ to flow out which produces the repolarizing phase. |
what creates the depolarization in an action potential? |
open-voltage gated Na+ channels allow Na+ to rush into the cell which causes depolarization. |
what creates the repolarization in an action potential? |
open-voltage gated K+ channels allow K+ to flow out which produces the repolarizing phase. |
the __________phase occurs when the voltage gated k+ channels remain open after the repolarizing phase |
after-hyperpolarizing |
an action potential occurs in the membrane of an axon of a neuron when depolarization reaches a certian level termed ____________. |
threshold |
what is threshold for an action potential? |
-55mV |
a ___________stimulus does not cause an action potential because it does not bring the membrane to threshold. |
subthreshold |
an action potential will occur in response to a __________ |
threshold stimulus |
describe the all or none principle for an action potential. |
an action potential either occurs or it doesnt. ex:dominoes all fall or they dont |
during the depolarizing phase, voltage gated Na+ channels ______rapidly. The inflow of Na+ changes membrane potential from -55mV to _______ |
open +30mV |
each voltage gated Na+ channel has two separate gates, ___________and _____________. In the resting state of a voltage gated Na+ channel, the inactivation gate is ________, and the activation gate is ________. |
activation gate inactivation gate open closed |
during repolarizing phase, activation gates of voltage gated Na+ channels _______ and the inactivation gates ______. |
open close |
the period of time after an action potential begins during which an excitable cell cannot generate another action potential in response to a normal threshold stimulus is called the _________. |
refractory period |
the _______is the period of time during which a second action potential can be initiated, but only by a larger then normal stimulus. |
relative refractory period |
how does local anesthetics work? |
they block the voltage gated Na+ channels, and action potentials can not propagate so pain does not reach the CNS |
name the two types of propagation |
saltatory conduction and continuous conduction |
________conduction requires step by step depolarization and repolarization of each adjacent segment in the plasma membrane |
continuous conduction |
___________, the special mode of action potential propagation that occurs along myelinated axons, occurs because of the uneven distribution of voltage gated channels. |
saltatory conduction |
name 3 factors that affect propagation |
1. amount of myelination-more myelin the faster it is 2. axon diamter-larger diameter are faster due to their large surfaces 3. temperature-faster when warmer, slower when cool |
Axons can be classified into 3 major groups based on amount of myelination, their diameters, and their propagation speeds. Name them. |
1. A fibers-largert diameter, myelinated, somatic sensory & motor to skeletal muscle 2. B fibers-medium diamtere, myelinated, visceral sensory autonomic preganglinic 3. C fibers-smallest diamter-unmyeliated, sensory & autonomic motor |
Name 7 differences between graded potentials and action potentials |
1. GP arise mainly in dendrites and cell body, while AP arise at trigger zone 2. GP use ligand gated ion channels, AP use voltage gated channels for Na+ and K+ 3. GP decremental(not propogated); short distance, while AP propagate and long distance 4. GP depends on strength of stimulus, AP is all or none 5. GP is longer, AP is shorter 6. GP may be hyperpolarizing or depolarizing, AP always consists of depolarizing followed by repolarizing phase and return to resting membrane potential 7. GP has no refractory period and summation can occur, AP has refractory period and summation cannot occur |
________is a region where communication occurs between two neurons or between a neuron and an effector cell. |
synapse |
______refers to a nerve cell that carries a nerve impulse toward a synapse. It is the cell that sends signals |
presynaptic neuron |
_____________is the cell that receives a signal |
psotsynaptic cell |
______means from axon to dendrite. ________means from axon to cell body. _______means from axon to axon |
axodendritic axosomatic axoaxonioc |
at _________synapse, AP conduct directly between plasma membranes of adjacent neurons through structures called __________. |
electrical synapse gap junction |
name the two main advantages of electrical synapses. |
faster communication and synchronzation |
in a chemical synapse plasma membranes are separated by the ____________ |
synaptic cleft |
____________gated channels are used in chemical synapses |
voltage gated Ca+ |
what type of synapse are the plasma membranes of a presynaptic and postsynaptic neurons? |
chemical and electrical synapse |
after neurotransmitter diffuses and binds to the receptors in the plasma membrane of the postsynaptic neurons, the postsynaptic neuron recieves an electrical/chemical signal and turns it into a ________________, a type of graded potential. |
chemical postsynaptic potential |
the presynaptic neuron converts a ____________signal(nerve impulse) into a ________signal (relaesed neurotransmitter) |
electrical chemical |
The postsynatic neuron recieves a ________signal and in turn generates a ___________signal (postsynaptic potential) |
chemical electrical |
describe the 7 steps of a typical chemical synapse |
refer to book page 474 |
A nerve impulse arrives at the ____________ of a presynaptic neuron. The depolarizing phase of the nerve impulse opens ____________channels which are present in the membrane of synaptic end bulbs. Because calcium ions are more concentrated in the extracellular fluid, _____flows _________through open channels. An increase in Ca2+ inside the presynaptic neuron serves as a signal that triggers _______of the synaptic vesicles. As vesicle membranes merge with the plasma membrane, ______________molecules within the vesicles are released into the synaptic cleft. The neurotransmitter molecules ____across the synaptic cleft and bind to _____________ in the postsnaptic neurons plasma membrane. Binding of neurotransmitter molecules to their receptors on _________gated channels opens the channels and allows particular ions to flow across the membrane. As ions flow through the open channels, the _______across the membrane changes. This change is called a ____________. Depending on which ions the channels admit, the postsynaptic potential may be a ___________ (excitation), or a ____________(inhibition). When a depolarization postsynaptic potential reaches ________, it triggers an ____________ in the axon of the postsynaptic neuron. |
synaptic end bulb voltage gated Ca2+ channels Ca2+ inward exocitosis neurotransmitter neurotransmitter receptors ligand gated channels voltage postsynaptic potential depolarization hyperpolarization threshold action potential |
at most chemical synapses only _________information transfer can occur.-from a presynaptic neuron to a potsynaptic neuron or a effector, such as a muscle fiber or gland cell. |
one way |
Action potentials move in only one/multiple directions |
only one-from presynaptic neuron to postsynaptic neuron |
a neurotransmitter can either cause a _________or _______graded potential. |
excitatory inhibitory |
a neurotransmitter that causes depolarization is excitatory/inhibitory because it brings the membrane closer to threshold |
excitatory |
a depolarizing post synaptic potential is called a ________________ |
excitatory postsynaptic potential (EPSP) |
a neurotransmitter that causes hyperpolarization of the postsynaptic membrane is ___________. |
inhibitory |
a hyperpolarizing postsynaptic potential is called a________________ |
inhibitory postsynaptic potential (IPSP) |
during hyperpolarization, generation of an action potential is harder because….? |
the membrane potential becomes inside more negative and thus farther from threshold then in its resting state. |
since each specific neurotransmitters has different binding sites, when a neurotransmitter binds to the correct receptor, a ________opens and a postsynaptic potential forms in the membrane of the _____________. |
ion channel postsynaptic cell |
what are the two types of postsynaptic potentials? |
EPSP-excitatory IPSP-inhibitory |
neurotransmitter receptors are classified as either _____________receptors or ___________receptors based on whether the the neurotransmitter beinding site and the ion channel are components of the same proteins or are components of different proteins. |
ionotropic metabotropic |
an ionotropic receptor when a neurotransmitter binding site and the ion channel are components of the same/different protein. |
the same |
an ionotropic receptor is a type of __________gated channel |
ligand |
when the correct neurotransmitter binds to an ionotropic receptor, the ion channel opens/closes and an EPSP or IPSP occurs in the postsynaptic cell. |
opens |
a metabotropic receptor is a type of neurotransmitter receptor, but lacks ____________. |
ion channels |
a metabotropic receptor is coupled to a seperate ion channel by a type of membrane protein called a _________. |
G protein |
a metabotropic receptor differs from ionotrophic receptors because the neurotransmitter binding site and ion channel are components of the same/different proteins |
different |
the greater the summation of EPSP, the greater/lesser the chance that threshold will be reached. |
greater |
name the 2 types of summation |
spatial and temporal |
___________summation is summation of postsynaptic potentials in response to stimuli that occur in at different locations in the membrane of a postsynaptic cell at the same time |
spatial summation |
spatial summation results from the buildup of neurotransmitter released simutaneoulsy by one/many presynaptic end bulbs. |
many |
________summation is summation of postsynaptic potentials in response to stimuli that iccur at the same location in the membrane of a postsynaptic cell but at different times. |
temporal |
temporal summationresults from buildup of neurotransmitter released by single/many presynaptic endbulb two or more times in rapid succession. |
single |
____________summation of effect of neurotransmitters released from 2 or more firing of the same end bulb in rapid succession onto a second neuron. |
temporal |
_____________summation of effects of neurotransmitters released from several end bulbs onto one neuron |
spatial |
nae the two categories of neurotransmitters |
small-molecule neurotransmitters neuropeptides |
name the 6 types of small-molecule neurotransmitters |
acetycholine amino acids biogenic amines ATP and other purines nitric oxide carbon dioxide |
__________neurotransmtter is released by many PNS neurons and by some CNS neurons |
acetylcholine |
________neurotransmitter is excitatory on NMJ but inhibitory at others |
acetylcholine |
_________neurotransmitter is inactivated by the enzyme acetycholinesterase |
acetylcholine |
___________ is an amino acid released by nearly all excitatory neurons in the brain-inactivated by glutamate specific transporters |
glutamate |
________ is in contrast to N20(laughing gas)smooth muscle relaxant |
nitric oxide |
____________is inhibitory neurotransmitter for 1/3 of all brain synapses (Valium is a GABA agonist—enhancing its inhibitory effect) |
GABA |
Name 4 amino acid neurotransmitters |
glutamate aspartate GABA glycine |
name 4 important biogenic amino acids |
norepinepherine epinephrine dopamine serotonin |
the neurotransmitter receptors can be acitvated or blocked. An agent that binds to receptors and enhances or mimics the effect of a natural neurotransmitter is called an ________. An agent that binds to block neurotransmitter receptors is called an ___________. |
agonist antagonist |
throught your life, your nervous system exhibits _________, the capability to change based on experience |
plasticity |
__________ cells are able to reproduce, but __________ are not |
neuoglia neurons |
how are individual nerves maintained throughout life? name 3 ways. |
sprouting new dendrites synthesis of new proteins changes in synaptic contacts with neurons |
_______ is the capability to replicate or repair themselves |
regeneration |
the __________nervous system may repair itself, while the __________nervous system has little to no repair. |
PNS CNS |
_______is the birth of new neurons from undifferentiated stem cells. |
neurogenisis |
axons and dendrites that are associated with the neurolemma may be repaired if…name 3 ways. |
-neuron cell body remains intact -schwann cells remain active and form a tube -scar tissue does not form too rapidly(3-5 days) |
degeneration of the distal potrion of the axon and myelin sheath is called ____________ |
wallerian degeneration |
what are neuropeptides composed of? |
3-40 amino acids |
what 3 ways is a neurotransmitter removed from the synaptic cleft? |
1. diffusion 2. enzymatic degradation 3. uptake by cells (neurons, neuroglia) |
at a chemical synapse between two neurons, the neuron receiving the signal is the ______________neuron, and the neuron sending the signal is celled the _______neuron |
postsynaptic presynaptic |
A&P2 Test 1-BOOK Chapter 12
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