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X Physiology 1A > The Nervous System > Flashcards

The Nervous System Flashcards

1
Q

What is the nervous system in charge of?

A

interaction between the body and the environment

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2
Q

What is the nervous system the main coordinator of?

A

body functions

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3
Q

What additional system does the nervous system work alongside with in order to coordinate body functions?

A

endocrine system

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4
Q

What are the 2 main components of the nervous system?

A

central and peripheral

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5
Q

What do neurons communicate between?

A

themselves and with other cells

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6
Q

What signals do neurons use to communicate between themselves and other cells?

A

electrical and chemical signals

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7
Q

What so dendrites do?

A

receive information that signals to the specific neurone

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8
Q

What is an axon?

A

pathway through which neurone signals to the next one in the chain

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9
Q

What do presynaptic terminals face into?

A

the synapse

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10
Q

Why are neurons excitable?

A

membranes have charges which change when they become activated and generate action potential

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11
Q

What is meant by directional flow of charge?

A

neurons only allow charge to flow in one direction through them

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12
Q

How do neurones communicate with each other and target cells using chemicals?

A

they release small quantities of chemical across the synaptic cleft from a presynaptic neurone to the post synaptic cell

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13
Q

What is the name of the chemicals used across synapses?

A

neurotransmitters/transmitters

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14
Q

Where are neurotransmitters stored?

A

vesicles in the presynaptic cell

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15
Q

What do synapses enable?

A

quick transfer of signal

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16
Q

How do synapses help with directional flow?

A

neurotransmitters only move one way

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17
Q

What are afferent neurons?

A

neurons towards the brain

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18
Q

What are efferent neurons?

A

neurons moving away from the brain towards effectors

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19
Q

What do interneurones do?

A

receive signals and process them within the brain or peripheral ganglia

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20
Q

How are structures which receive/process sensory information located anatomically in relation to structures that control efferent output?

A

posterior

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21
Q

What is the CNS composed of?

A

brain and spinal chord

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22
Q

What divisions is the PNS composed of?

A

afferent and efferent divisions

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23
Q

What are the 3 branches of the afferent division of the PNS?

A

somatic sensory, visceral sensory (autonomic), special sensory

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24
Q

What are the 2 branches of the efferent division of the PNS?

A

somatic motor, autonomic (visceral)

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25
Q

What are the 3 divisions of the efferent autonomic system of the PNS?

A

sympathetic, parasympathetic, entric

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26
Q

What are the 4 lobes of the brain (human)?

A

frontal, occipital, parietal, temporal

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27
Q

What are the 2 key areas of the forebrain?

A

cerebrum, diencephalon

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28
Q

What is the brain stem the centre for?

A

information essential to life (e.g. respiration/heart rate)

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29
Q

What are the 3 key elements of the brainstem?

A

midbrain, Pons, medulla oblongata

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30
Q

What is the cerebellum used for?

A

balance and posture (bigger in quadrupeds)

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31
Q

What is the vagus nerve?

A

key nerve in autonomic nervous system

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32
Q

Where does information enter the spine via afferent nerves?

A

dorsal horn

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33
Q

Where does information leave the spine via efferent nerves?

A

ventral horns

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34
Q

What are the ventral horns composed of?

A

long axons of neurons located in the grey matter

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35
Q

Why do nerves not correspond to the segments of the spinal chord once we reach adulthood?

A

are an exact match when we are born, as we grow the spinal column grows more than nerve tissue so the exits no longer match the locations of the nerves

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36
Q

What are the 4 areas of the spine?

A

cervical, thoracic, lumbar, sacral

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37
Q

What are high density clusters of neurones called in the brain?

A

nuclei

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38
Q

What are high density clusters of neurons called in the peripheral nervous system?

A

ganglia

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39
Q

why is the phospholipid bilayer a good electrical insulator?

A

impermeable to ions

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40
Q

Is the concentration of sodium ions higher inside the cell or outside?

A

outside (145 mM)

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41
Q

is the concentration of potassium ions higher inside or outside the cell?

A

inside (140 mM)

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42
Q

What is an example of an active ion transporter?

A

sodium potassium pump

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43
Q

how many potassium ions are moved for 3 sodium ions?

A

2

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44
Q

What do ion channels allow?

A

ions to pass through plasma membrane down a concentration gradient

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45
Q

What are leaky ion channels?

A

channels that always allow ion movement

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46
Q

What are gated ion channels?

A

ion channels that remain closed until a threshold is reached which causes them to open

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47
Q

What are 2 examples of gated ion channels?

A

voltage gated and ligand gated

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48
Q

Does potassium diffuse into or out of the cell down it’s concentration gradient?

A

out of the cell

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49
Q

What happens when positively charged potassium leaves the cell?

A

takes charge with it so cell becomes more negatively charged compared to the outside of the cell

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50
Q

What sort of potential can the movement of K+ ions out of the cell create?

A

negative membrane potential

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51
Q

What happens when movement of K+ ions out of the cell causes the cell to reach a threshold of electrochemical gradient?

A

no more net movement of potassium ions out of the cell

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52
Q

What happens at the balanced equilibrium potential?

A

concentration gradient one way is equal to the electrochemical gradient the other

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53
Q

What does the Nernst equation predict?

A

equilibrium potential for a particular type of ion

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54
Q

What is the RMP of a neuron?

A

-70 mV

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55
Q

What is the equilibrium potential of K+?

A

-95mV

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56
Q

What is the equilibrium potential of Na+?

A

+61mV

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57
Q

What is the equilibrium potential of Cl-?

A

-90mV

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58
Q

Which of the three main ions resting potential is the main determinant of resting membrane potential?

A

K+

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59
Q

What can be used to predict membrane potential?

A

relative permeabilities of ions

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60
Q

What does a relative permeability of 1 mean for ions?

A

high, flow through channels all the time

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61
Q

What does a relative permeability of 0 mean for ions?

A

very low, ions barely passing through channels

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62
Q

What happens to the membrane potential of a cell during an action potential?

A

fast changes in the membrane potential of the cell from positive to negative and back

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63
Q

What is an action potential?

A

brief ‘all or nothing’ depolarisation of neuronal membrane

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64
Q

How is the signal information encoded in an action potential?

A

by frequency and pattern of signal not by amplitude

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65
Q

What happens to the signal as it is propagated along cell membrane and axon?

A

the signal will remain the same

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66
Q

Once threshold has been reached what changes occur in the amplitude of the action potential?

A

none, even if a stronger signal is given the amplitude will stay the same

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67
Q

If the threshold is not reached will the signal be transferred?

A

no

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68
Q

What are fluxes of Na+ and K+ ions coordinated by?

A

voltage gated ion channels

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69
Q

What sort of polarisation of the cell membrane are Na+ ions involved with?

A

depolarisation

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70
Q

What sort of polarisation of the cell membrane are K+ ions involved with?

A

repolarisation

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71
Q

What is the Na+ ion channel controlled by?

A

potential of the membrane

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72
Q

What is the Na+ ion channel closed by?

A

flexible protein in the mouth of the channel

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73
Q

What does the charge of the amino acid/protein closing the Na+ ion channel react with?

A

charge inside the cell membrane

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74
Q

What must happen in order to initiate AP?

A

membrane must be depolarized

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75
Q

What does the need for membrane depolarization explain?

A

the threshold required before an AP is propogated

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76
Q

What feedback mechanism is responsible for the dynamic and speed of an action potential?

A

positive feedback mechanism

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77
Q

What effect does depolarization of the membrane have on Na

+ channels?

A

opening of voltage gated Na+ channels which results in sodium currents depolarizing membrane further

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78
Q

What can be done to stop the positive feedback mechanism and ensure an action potential comes to an end?

A

when channel is depolarized an inactivation gate covers the end of the sodium channel found in the cell

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79
Q

What stroke of the action potential are sodium channels responsible for?

A

upstroke

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80
Q

What happens to K+ ion channels in response to the depolarization of membrane?

A

delayed response results in K+ channels opening so K+ rapidly exits cell and so cell becomes more negative (polarized) again

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81
Q

What are the 3 states a sodium channel can be in?

A

closed, open, inactivated

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82
Q

What are the 2 states a potassium channel can be in?

A

closed or open

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83
Q

During depolarisation what happens to Na+ and K+ ion channels?

A

Na+: closed to open to inactivated

K+: closed to open

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84
Q

During repolarisation what happens to Na+ and K+ ion channels?

A

Na+: inactivated to open to closed

K+: open to closed

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85
Q

What is needed to reverse the inactivation of sodium channels?

A

negative membrane potential

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86
Q

What are the 2 factors responsible for the termination of action potential?

A

inactivation of Na+ channels

delayed activation of K+ channels

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87
Q

What are the K+ channels also known as when opening after the depolarization of the membrane?

A

delayed rectifiers

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88
Q

What is the structure of the protein the Na+ channel made of?

A

single protein with 4 subunits

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89
Q

What is the structure of the protein the K+ channel is made of?

A

4 subunits are made from separate proteins

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90
Q

Where is the action potential generated in central neurons?

A

initial segment

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91
Q

What is found in large quantities in the initial segment of central neurons?

A

many Na+ channels

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92
Q

What does tetrodotoxin do?

A

blocks voltage gated sodium channels

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93
Q

What are the 2 phases of the refractory period?

A

Absolute and relative

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94
Q

Can action potential be generated in a cell in absolute refractory period?

A

no AP cannot occur under any circumstances

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95
Q

Can action potential be generated in a cell in relative refractory period?

A

a stronger than normal stimulus may evoke AP

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96
Q

What does sodium/potassium ATPase maintain and restore?

A

ion gradient and restores ion concentrations after action potential

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97
Q

what is sodium/potassium ATPase dependent on as an ion transporter?

A

ATP

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98
Q

Why is sodium/potassium ATPase electrogenic?

A

generates negative charge within cell

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99
Q

Where is AP propagated in mylinated cells?

A

nodes of ranvier

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100
Q

What is saltatory conduction?

A

AP jumps from one node of ranvier to next

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101
Q

How does saltatory conduction improve AP propagation?

A

increases the speed and saves energy

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102
Q

How does saltatory conduction save energy?

A

ion concentration does not have to be restored along the whole length of the cell

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103
Q

How quickly do thick, well myelinated axons conduct?

A

fast

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104
Q

How quickly do unmyelinated axons conduct?

A

slower

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105
Q

What is the neuromuscular junction?

A

synapse between presynaptic motor neuron and postsynaptic muscle

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106
Q

What does a chemical synapse do?

A

mediates signal propagation from neuron to posy synaptic cell

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107
Q

What is the synaptic cleft?

A

gap between pre and post synaptic cells

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108
Q

What direction does the electrical signal travel across a synapse?

A

from presynaptic terminal to post synaptic cell

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109
Q

What must happen in order for the electrical signal to cross the synaptic cleft?

A

must be converted into a chemical signal

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110
Q

What is the neurotransmitter found at neuromuscular junctions?

A

Acetylcholine

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111
Q

Where is acetylcholine produced?

A

presynaptic terminal

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112
Q

What enzyme produces acetylcholine?

A

choline acetyl transfurase

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113
Q

What does choline acetyl transfurase do in order to form acetylcholine?

A

attaches acetyl group to from acetyl-CoA to choline

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114
Q

Where is acetylcholine stored in the presynaptic cell?

A

vesicles

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115
Q

What transporters move acetylcholine into vesicles in the presynaptic cell?

A

uptake transporters

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116
Q

Where on a muscle cell is the neuromuscular junction usually found?

A

towards the middle of the cell

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117
Q

Why are there lots of mitochondria present in the presynaptic cell?

A

synaptic transmission requires a lot of metabolic energy

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118
Q

What type of ion channel is found in the presynaptic membrane?

A

voltage gated Ca2+

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119
Q

what types of ion channels are found in the post synaptic membrane?

A

voltage gated Na+ channels

ligand gated channels

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120
Q

Is the intracellular concentration of Ca2+ in the cell high or low compared to outside the cell?

A

low

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121
Q

by what process is the neurotransmitter released from the presynaptic cell?

A

Ca2+ dependent exocytosis

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122
Q

What happens when a membrane is depolarized?

A

there is a positive shift in the membrane potential

123
Q

What happens in the presynaptic cell when the action potential arrives at presynaptic terminal?

A

membrane is depolarized

124
Q

What does the depolarization of the presynaptic membrane trigger?

A

Ca2+ channels to open so that calcium levels in the cell begin to rise

125
Q

As calcium diffuses into the presynaptic cell what does it signal to?

A

elements that cause transmitter vesicles to dock to the presynaptic membrane

126
Q

What is the name of the proteins in the presynaptic membrane which enable the transmitter vesicles to dock?

A

snare proteins

127
Q

When a transmitter vesicle membrane fuses with the presynaptic membrane by what process does the transmitter then exit the vesicle and cell into the synaptic cleft?

A

exocytosis

128
Q

Once in the synaptic cleft what happens to neurotransmitter?

A

diffuses to post synaptic cell and the acetylcholine receptors in it’s surface

129
Q

What postsynaptic ion channels are acetylcholine receptors examples of?

A

ligand gated ion channels

130
Q

What is the name of the acetylcholine receptor?

A

nicotinic acetylcholine receptor (nAChR)

131
Q

Is nicotinic acetylcholine receptor (nAChR) a selective or non-selective ion channel?

A

non-selective

132
Q

How many binding sites for acetylcholine does nAChR have?

A

2

133
Q

What happens to nAChR when 2 acetylcholine molecules have bound to it?

A

becomes activated and opens to allow ions to pass through such as Na+

134
Q

How many different sub-units is nAChR formed of?

A

5

135
Q

What effect does Na+ entering the post synaptic cell through nAChR have on the muscle fibre membrane?

A

depolarization and creation of end plate potential

136
Q

What has to happen at the post synaptic muscle cell in order for movement to occur?

A

threshold has to be reached so that action potential (end plate potential) can be propagated

137
Q

What does the creation of end plate potential in muscle cells lead to?

A

muscle contraction

138
Q

Where are sodium channels and nAChRs present in the muscle cell?

A

sodium channels: all along muscle cells

nAChRs: only in post synaptic endplate

139
Q

Why does transynaptic signal need to be controlled?

A

to keep endplate potential short and make the transmission meaningful/useful

140
Q

What is used to terminate the transynaptic signal?

A

enzymes in the synaptic cleft

141
Q

What do enzymes in the synaptic cleft do to ACh?

A

split ACh into acetyl and choline

142
Q

What is the name of the enzyme which breaks down ACh in order to terminate transynaptic signal?

A

acetylcholine esterase

143
Q

What happens to the acetyl and choline that are broken down by acetylcholine esterase in the synaptic cleft?

A

reabsorbed into terminals and used to create acetylcholine again

144
Q

In the CNS what are pre and post synaptic cells fomed of?

A

neurons

145
Q

What is neural convergence?

A

many neurons impart signal onto a single neuron

146
Q

what is neural divergence?

A

single neuron can signal to many different postsynaptic neurons/cells

147
Q

What do dendritic spines on dendrites do?

A

increase contact surface area for synaptic contacs

148
Q

Is there chemical diversity in the neurotransmitters and neuromodulators of the CNS?

A

yes

149
Q

Name 6 potential neurotransmitter/neuromodulator types in the CNS

A 
amino acids
acetylcholine
biogenic amines
neuropeptides
purines 
gases
150
Q

What is an example of a amino acid neurotransmitter?

A

glutamate/GABBA

151
Q

What does Dale’s principal suggest?

A

single neurons will specialise, they will be exitatory or inhibitory and so use a specific neurotransmitter in all synapses

152
Q

Can a presynaptic neuron contain more than one neurotransmitter?

A

yes, often an exitatory and inhibitory

153
Q

What is the difference in appearance between excitatory and inhibitory synapses?

A

excitatory: densities on both sides of the synapse are asymmetrical
inhibitory: symmetrical synaptic density

154
Q

Can you have both exitatory and inhibitory synapses on one dendrite?

A

yes

155
Q

Where is glutamate stored in the presynaptic cell?

A

vesicles near the presynaptic membrane

156
Q

What is one of the most abundant receptors in the central nervous system?

A

ionotropic glutamate receptor (AMPA)

157
Q

What type of ion channel is ionotropic glutamate receptor (AMPA)?

A

ligand gated ion channel

158
Q

how many subunits is ionotropic glutamate receptor (AMPA) made up of?

A

4

159
Q

What ions is ionotropic glutamate receptor (AMPA) permeable to when activated?

A

Na+, K+ and sometimes Ca2+

160
Q

What is ionotropic glutamate receptor (AMPA) activated by?

A

2-4 glutamate molecules

161
Q

How is ionotropic glutamate receptor (AMPA) deactivated?

A

unbinding of glutamate that leads to the closing of the channels

162
Q

What sort of depolarization is excitatory postsynaptic potential?

A

graded depolarization

163
Q

What does graded deploarization by ESPS do to the membrane potential?

A

moves the membrane potential closer to the threshold for firing an action potential

164
Q

What effect does deploarization always have on the membrane potential?

A

makes it more positive

165
Q

What happens if action potential reached at initial axon segment?

A

action potential is created

166
Q

What does the level of depolarization by EPSP depend on?

A

the number of AMPA receptors opened

167
Q

What is the major central inhibitory receptor type?

A

GABA receptor

168
Q

What is GABA?

A

gamma-amino-butyric acid

169
Q

What does GABA have a simular structure to?

A

glutamate

170
Q

What type of ion channel is GABA receptor?

A

ligand gated ion channel

171
Q

How many subunits does GABA receptor have?

A

5

172
Q

What is the GABA receptor structure similar to?

A

nAChR

173
Q

How does GABA receptor differ from nAChR?

A

it only accepts negative ions

174
Q

What is the GABA receptor activated by?

A

2 GABA molecules binding

175
Q

How is the GABA receptor deactivated?

A

unbinding of GABA molecules which then return to their resting state

176
Q

What sort of polarization is inhibitory postsynaptic potential?

A

graded hyperpolarization

177
Q

What does the degree of graded hyperpolarization during IPSP depend on?

A

the number of GABA channels open

178
Q

What does graded hyperpolarisation by IPSP do?

A

moves the membrane potential further from the threshold for firing an action potential

179
Q

What does it mean if the membrane has become more polarized?

A

membrane is more negative

180
Q

How is the membrane made more negative during IPSP?

A

influx of chloride ions

181
Q

Compared to active transport how fast is synaptic transmission?

A

slow

182
Q

What is good about synaptic transfur that cannot occur during the electrical transmission of action potential?

A

allows for multiple signal integration of incoming signals and this integration will them compute if active transport should be propagated

183
Q

How does a neuron decide if an action potential will be propagated?

A

EPSP and IPSP are combined ‘summed up’ to decide if action potential will be triggered

184
Q

What is spatial summation?

A

PSP’s from different synaptic inputs arriving in the postsynaptic neuron at the same time

185
Q

What is temporal summation?

A

PSP’s from different synaptic inputs arriving in the postsynaptic neuron in quick succession

186
Q

What happens if the sum of PSP’s reaches the action potential threshold?

A

action potential can be triggered at axon hillock

187
Q

Can combination of EPSP and IPSP lead to no response?

A

yes

188
Q

Give an example of presynaptic inhibition

A

inhibition of presynaptic Ca2+ channels

189
Q

give an example of presynaptic excitation?

A

increase of presynaptic Ca2+ levels

190
Q

What can synaptic efficiency be modulated by?

A

metabotrophic receptors

191
Q

What type of nervous structures are sensory receptors?

A

specialised

192
Q

What do sensory receptors allow us to receive?

A

information about the external and internal environment

193
Q

where is information from sensory receptors sent for processing?

A

CNS

194
Q

What are specialized nerve cells able to detect?

A

one form of energy which triggers an action potential

195
Q

What are the 2 types of sensory receptor?

A

specialised endings of afferent neurons or separate cells that signal to the afferent neuron

196
Q

Sensory receptors that use specialised cells are not directly linked to the ___?

A

brain

197
Q

Sensory receptors are ___ of energy?

A

transducers

198
Q

What does a transducer do?

A

converts one form of energy (e.g. heat) into another form of energy (e.g. electrical energy)

199
Q

what is depolarization at a sensory terminal called?

A

receptor potential

200
Q

What does graded mean in terms of receptor potential?

A

proportional to stimulus strength

201
Q

What does non-propagating mean in terms of receptor potential?

A

it is confined to the sensory terminal

202
Q

What happens if the receptor potential in a sensory terminal is large enough?

A

it will evoke an action potential along the nerve fibre

203
Q

What does an increase in stimulus strength mean for the amount of neurotransmitter released from the pre-synaptic neurone of the sensory organ?

A

increase in stimulus will lead to an increased amount of neurotransmitter released

204
Q

What effect does the increased amount of neuro transmitter released by a more intense stimulus have on the CNS?

A

helps CNS to be aware of the intensity of the stimulus and so coordinate an appropriate response

205
Q

If the stimulus is intense what effect does this have on action potential of the afferent sensory neurone?

A

more action potentials are produced the more intense the stimulus is

206
Q

Does action potential frequency vary depending on the stimulus?

A

yes

207
Q

What does adaption to a stimulus prevent?

A

sensory overload

208
Q

what does the speed of adaption to stimuli depend on?

A

the receptor type as they vary in their speed of adaption to stimuli

209
Q

What is reduced in the sensory organ by frequent exposure?

A

receptor potential

210
Q

What sensory receptors are often fast acting?

A

pressure/touch

211
Q

What does it mean if a receptor is fast adapting to a stimulus?

A

action potential firing reduces quickly during continued exposure to stimulus

212
Q

What sensory receptors are often slow acting?

A

muscle stretch receptors

213
Q

Why is it important that muscle stretch receptors are slow acting?

A

the body needs constant feedback in order to aid proprioception and prevent damage

214
Q

When do fast adapting fibres often see a second spike in action potential?

A

when stimulus stops/is removed - the off response

215
Q

What do temperature dependent ion channels open in response to?

A

temperature increase of membrane

216
Q

How is an action potential created by temperature dependent ion channels?

A

channels permeable to positive ion (Na+), this depolarizes the membrane and an action potential is created

217
Q

What can ion channels in sensory receptors be sensitive to?

A

different stimuli

218
Q

Why is a receptor specific to one energy or stimulus?

A

it is most sensitive to that energy

219
Q

Can receptors be stimulated by energy other than that which they are specific to?

A

yes but only if that stimulus is of very high intensity

220
Q

Give 3 types of receptors

A

mechanoreceptors
photoreceptors
chemoreceptors

221
Q

What helps to increase the precision of the detection of a stimulus?

A

a narrow receptive field

222
Q

What can overlapping stimulation between neighboring receptive fields help to provide?

A

general information about the location of a stimulus

223
Q

What do specific ascending nervous pathways maintain with regards to modality of the stimulus?

A

modality from detection to processing. The stimulus is not mixed with others by convergence of neurons

224
Q

What do non-specific ascending pathways do with stimulus information from sensory neurons?

A

it is combined with other stimuli at the spinal cord during convergence of neurons

225
Q

What is the difference in clarity between specific and non-specific ascending pathways?

A

specific is very clear

non-specific is less clear so we cannot be sure of the type of stimulus

226
Q

What information do non-specific ascending pathways give?

A

background information

227
Q

What is the main reason for referred pain from visceral organs?

A

convergence of sensory pathways

228
Q

Give and example of referred pain

A

left arm pain during myocardial ischemia/infarction

229
Q

Where is the final destination in the brain for sensory information?

A

somatosensory cortex

230
Q

What will stimulation of the correct area o the cortex lead to?

A

sensation in the area body that corresponds to the area of the brain being stimulated

231
Q

Where can afferent information be modulated prior to reaching the brain?

A

spinal cord

232
Q

Why may the CNS suppress pain signals temporarily?

A

to increase survival chances in a fight/flight situation

233
Q

What can happen in the dorsal horn to alter sensation of pain?

A

suppression of the action of neurotransmitters from the sensory afferent neuron

234
Q

What part of the nervous system operates without conscious command?

A

ANS - autonomic nervous system

235
Q

What sort of functions in the body is the ANS responsible for?

A

critical

236
Q

What functions do the ANS and endocrine systems control in the body?

A

internal organs, biochemical composition of the body and metabolism

237
Q

name 6 diseases which involve ANS imbalances

A

arterial hypertension
gastric ulcers
heart rhythm abnormalities
depression/anxiety/parkinsons

238
Q

Give 2 examples of conditions treated by drugs which act via ANS synapses

A 
nasal congestion (common cold)
bronchial asthma
239
Q

In the parasympathetic system where does the preganglionic neuron synapse with the effector organ?

A

inside or on the surface of the effector organ

240
Q

What is the name of the efferent neurons of the CNS before they synapse with effector organs?

A

preganglionic

241
Q

In the sympathetic system where does the preganglionic neuron synapse with the effector organ?

A

outside the effector organ within the sympathetic chain

242
Q

What is the entric nervous system?

A

located in the intestine, under partial control of ANS sympathetic and parasympathetic pathways

243
Q

Where does the parasympathetic nervous system originate from the spinal cord?

A

caudal aspect of the medulla oblongata/cranial nerves and sacral nerves

244
Q

What number cranial nerve is the vagus nerve?

A

10

245
Q

What do the sacral nerves of the parasympathetic nervous system control?

A

lower intestine, bladder and genitalia

246
Q

Where are the parasympathetic ganglia located?

A

next to/ in the wall of the target effector organ

247
Q

Where does the sympathetic nervous system originate from the spinal cord?

A

thoracic and upper lumbar sections of the spine

248
Q

Where are sympathetic chain ganglia located?

A

where the first neuron/ preganglionic neuron synapses with the second/ post ganglionic neuron, para medial to the spinal cord

249
Q

Does the CNS direct the synapses in the parasympathetic and sympathetic nervous systems?

A

no, ganglion do

250
Q

Where do sympathetic fibres of the ANS originate from in the spinal cord?

A

cell bodies located between dorsal and ventral horns (known as the lateral horn)

251
Q

Where does the efferent part of the sympathetic fibres leave the spinal cord?

A

ventral horn into the sympathetic chain

252
Q

What are the main neurotransmitters in autonomic synapses?

A

acetylcholine

noradrenaline

253
Q

What amino acid is noradrenaline a derivative of?

A

tyrosine

254
Q

Where in the body does adrenaline originate?

A

the adrenal medulla

255
Q

Is adrenaline released in sympathetic synapses?

A

no

256
Q

In what synapses is acetylcholine used in the parasympathetic nervous system?

A

ganglionic synapse and effector organ synapse

257
Q

In what synapses is acetylcholine used in the sympathetic nervous system?

A

ganglionic synapse

258
Q

In what synapses is noradrenaline used in the sympathetic nervous system?

A

effector organ synapse with sympathetic post ganglionic neurons

259
Q

What is the central organ of the adrenal gland?

A

adrenal medulla

260
Q

Where is the adrenal gland located?

A

superior surface of the kidney

261
Q

What system does the adrenal medulla supply endocrine output for?

A

CNS

262
Q

What neurotransmitter is used between CNS ad adrenal medulla?

A

acetylcholine

263
Q

When the adrenal medulla is signaled by acetylcholine what does it release?

A

adrenaline and noradrenaline

264
Q

what is adrenaline directly released into from the adrenal medulla?

A

the bloodstream

265
Q

How does the sympathetic nervous system affect the eye?

A

causes dilation of iris

266
Q

How does the sympathetic nervous system cause dilation of the iris?

A

controls the radial fibres of the iris, the contraction of radial fibres pulls the inner circle muscles outwards

267
Q

How does the sympathetic nervous system affect the trachea and bronchi?

A

dilate in order to increase air flow

268
Q

How does the sympathetic nervous system affect the heart?

A

increase in heart rate and force of contraction

269
Q

what does an increase in heart rate and force of contraction of the heart mean will happen?

A

more blood is pumped and more oxygen delivered to tissues

270
Q

How does the sympathetic nervous system affect the circulatory system?

A

arterioles constrict to redirect blood in favor of critical organs

271
Q

Where is there strong constriction of arterioles in response to the sympathetic nervous system?

A

skin, abdominal viscera and kidneys

272
Q

Where is there weak constriction (relaxation) of arterioles in response to the sympathetic nervous system?

A

heart, brain, lungs and muscles

273
Q

Why may veins also constrict in response to the sympathetic nervous system?

A

more blood returns to the heart for faster re-circulation

274
Q

How does the sympathetic nervous system affect systemic blood pressure?

A

increase in cardiac output, increase in resistance to blood flow, increased return of venous blood

275
Q

what effect does increased systemic blood pressure have on oxygen and CO2 levels?

A

oxygen is gained and CO2 removed from the body quicker

276
Q

What are the 2 types of adrenoreceptor in the liver?

A

alpha and beta

277
Q

What are the 2 ways that the liver releases glucose?

A

glucogenolysis and glyconeogenesis

278
Q

which is faster: glucogenolysis and glyconeogenesis?

A

glycogenolysis

279
Q

how does glucogenolysis release glucose?

A

from glycogen storage

280
Q

how does glyconeogenesis release glucose?

A

new glucose is made from amino acids

281
Q

What do glucogenolysis and glyconeogenesis lead to in the blood?

A

increase in blood glucose

282
Q

What is the primary food for the brain?

A

glucose

283
Q

what type of adrenoreceptor is found in skeletal muscle?

A

beta

284
Q

What effect does the sympathetic nervous system have on skeletal muscle?

A

increased contractility, glycogenolysis (energy supply)

285
Q

When is the parasympathetic nervous system dominant?

A

at rest and during sleep

286
Q

is near vision an active or passive process?

A

active

287
Q

How does the parasympathetic nervous system affect the eye?

A

contraction of circular muscle of the iris to contract pupil

288
Q

What effect does the contraction if the iris have on the eye?

A

reduces the amount of light reaching the retina

289
Q

What needs to happen to the lens of the eye in order to focus on near objects?

A

increase in curvature of the lens is needed in order to focus light from near objects onto the retina

290
Q

What shape is the lens of the eye naturally?

A

round

291
Q

What fibres keep the lens flat in the eye?

A

zonular fibres

292
Q

What effect does cilliary muscle have on the lens?

A

contracts to counteract zonular fibres so lens becomes more round

293
Q

How does the parasympathetic nervous system affect the glands of the salivary and GI tract?

A

increase in gland secretion

294
Q

How does the parasympathetic nervous system affect the GI tract?

A

increased motility of stomach and intestine

295
Q

How does the parasympathetic nervous system affect the respiratory system?

A

trachea and bronchi constrict

296
Q

What is the benefit of the constriction of the trachea and bronchi by the parasympathetic nervous system?

A

inhaled air can be cleaned more easily and pollutants removed

297
Q

How does the parasympathetic nervous system affect the cardiovascular system?

A

heart rate and force of contraction reduce

298
Q

What does the afferent part of the ANS monitor?

A

condition of body

299
Q

Where is afferent information of the ANS processed?

A

the brain, mainly the medulla

300
Q

What is afferent information of the ANS supplied from?

A

receptors all around the body

301
Q

How does the body compensate for any differences from set point?

A

activates ANS

302
Q

What body process is the afferent part of the ANS a key part of?

A

homeostasis

303
Q

What are visceral or autonomic reflexes?

A

triggering of responses via the ANS by visceral and somatic afferents

X Physiology 1A (9 decks)

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