問題一覧
1
the basic functional units of the nervous system are individual cells called
neurons
2
supporting the cells of the nervous system, called neuralgia, perform all of the following except
act as lymphocytes
3
what is the term for the nervous system comprising all neurons outside the brain and spinal cord
peripheral nervous system
4
the autonomic nervous system provides regulation of each of the following except
skeletal muscle
5
which of the following is NOT a basic function of the nervous system
interpretative
6
neurons are classified on the basis of structure as each of the following except
dipolar
7
the multipolar neuron consists of all of the following excepr
myelin
8
the axons of some neurons are wrapped in an insulating sheath made of
myelin
9
the insulating sheath is interrupted at regular intervals, exposing the neural membrane. these interruptions are called ? of ranvier
nodes
10
neurons use ? to carry information from the cell body to the synaptic terminal
electrical impulses
11
an action potential is a change in membrane potential during ? of a neuron
excitation
12
where in a neuron is the highest density of voltage gated sodium channels found
axon hillock
13
events that make initiation of an action potential less likely are
inhibitory
14
which of the following is a correct step in the generation of an action potential
inactivation of sodium channels and the activation of potassium channels
15
from the time an action potential begins until the normal resting potential has stabilised, the membrane will not respond normally to additional depolarising stimuli, this period is known as the
refractory period
16
in a neural action potential repolarisation involves the loss of ? ions
potassium
17
the ? exchange pump slowly restores intracellular and extracellular ion distribution to pre stimulation levels when the neuron is not active
sodium potassium
18
an action potential is delayed along the axon of a neuron in a series of steps, with action potentials in one section of the axon bringing the adjacent region to ? and handing on the impulse
threshold
19
continuous propagation is the basic mechanism by which an action potential is propagated along a ? appearing to move along the membrane in a series of tiny steps
unmyelinated axon
20
where action potentials jump along the axon in a series of steps, this is known as
saltatory propagation
21
electrical impulses are passed from neurons or other cells at a specialised junction called
synapse
22
electrical synapses are rare and occur when presymaptic and postsynaptic membranes are locked together tightly by
gap junctions
23
in a chemical synapse, communication across the synaptic cleft requires the release of a ? from the presynaptic membrane
neurotransmitter
24
according to the lock and key model, the same neurotransmitter may act on
several different types of receptors
25
substance start can bind to a receptor are called ligands. ligands that block or reduce neurotransmitter action are called
antagonist
26
neurotransmitters that may be either excitatory or inhibitory depending on the postsynaptic receptor are called ? neurotransmitter
dual function
27
ACh is the neurotransmitter of the neuromuscular junction, the specialised synapse between a motor neuron and a muscle, where it acts on the ? ACh receptor
nicotinic
28
which of the following is not an accurate event at the cholinergic synapse
calcium ions enter the synaptic terminal from the intracellular calcium stores, triggering the exocytosis of ACh
29
when signals from another nerve terminal at the presynaptic membrane causes a decreased release of neurotransmitter, it is called
presynaptic inhibition
30
an excitory postsynaptic potential is a ? caused by the arrival of a neurotransmitter
graded depolarisation
31
individual postsynaptic potentials can combine by the process of summation, which integrates the effect of
graded potentials
32
the addition of stimuli occurring in rapid succession is called
temporal summation
33
a reflex arc contains each of the following except
am efferent junction
34
the region of the brain which performs higher functions and planning and execution of voluntary motor action is called the
cortex
35
the electroencephalogram provides a clinical assessment of overall brain function, and records each of the following except
sigma waves
36
the ? is an area of the brain responsible for maintenance of homeostasis by controlling behaviours essential to survival of the individual or species via hormones and the sympathetic nervous system
hypothalamus
37
activation of the ? branch of the autonomic nervous system causes rest and repose responses, associated with relative inactivity and digestion
parasympathetic
38
a number of organs have ? by both sympathetic and parasympathetic nerves, with opposite effects
dual innervation
39
the principle neurotransmitter of the sympathetic nervous system, which may act on alpha and beta reception is
no adrenaline
40
the principle neurotransmitter of the parasympathetic system is ? acting on muscarinic receptors
acetylcholine (ACh)
41
what is the relationship between action potentials abs graded potentials
action potentials are initiated when the membrane is depolarised to threshold by a graded potential
42
why do voltage regulated K+ channels not need to inactivate
because the equilibrium potential for K+ is lower that the threshold of the K+ channels (ca -60 mV)
43
which feature of voltage regulated ion channels is responsible for neurons refractory period
Na+ channel inactivation
44
why can an action potential not be initiated during the refractory period?
because the voltage gated Na+ channels are inactivated
45
why does continuous propagation of the action potential not occur in the myelinated axons
because the myelin sheath blocks the flow of ions across the membrane
46
why do action potentials travel along distances while graded potentials do not
because action potentials are actively propagated
47
what determines the duration of an action potential
cell type
48
which of the following cannot initiate a graded potential
action potentials
49
pick the correct statement. at a chemical synapse
generally communication only occurs in one direction
50
what terminates transmission at the cholinergic synapse?
breakdown of ACh by AChE
51
pick the correct statement. slow postsynaptic receptors
may trigger more than one response in the postsynaptic cell
52
what function of neurons is performed by summation
integration of several different synaptic inputs
53
why do alkalosis and acidosis affect neural impulse conduction
because the concentration of H+ affects the potential difference across the cell membrane
54
atropine binds to muscarinic acteylcholine receptors and prevents their activation by acteylcholine. Thai means it acts as an
antagonist
55
selective serotonin regulator inhibitors prolong the action of serotonin (5HT) at a synapse by preventing its removal from the synaptic cleft. this means they act as
agonists
56
Parkinson’s diseases is caused by deficient dopamine pathways in the brain. it is therefore best treated with
dopamine agonists
57
the tendon stretch reflex can be classified as a
monosynaptic reflex
58
damage to which areas of the brain would be expected to impair control of food intake
hypothalamus
59
which of the following is part of the rest and repose response
decrease in heart rate