Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

module 5 communication, homeostasis and energy > 5.3 neural communication > Flashcards

5.3 neural communication Flashcards

1
Q

define sensory receptors

A

specialised cells that can detect changes/ of internal or external environments and can create an action potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

define transducer

A

a cell that converts one form of energy into another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what type of signal is created in the form of electrical energy

A

nerve impulse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

define pacinian corpuscles

A

a pressure sensor that detects changes in pressure on the skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what do photoreceptors(cones/rods) detect and where

A

changes to light intensity
retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what do audio receptors detect and where

A

changes to sound/ vibrations
ear/cochlea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does the pacinian corpuscle detect and where

A

changes to pressure
skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what do oflactory cells detect and where

A

chemicals in the air
nose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what do chemoreceptors detect

A

changes to chemicals in food/air etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

describe the structure of a pacinian corpuscle

A

oval shaped
series of concentric rings of connective tissue
around the end of a nerve cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what happens when pressure on the skin changes

A

pacinian corpuscle rings of connective tissue deforms which pushes against nerve ending

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how are nerve impulses generated

A

when pressure changes/ PC deforms = sodium channels are forced open
sodium cells diffuse into the cell
generator potential produced
Na+/K- pump in the membrane pumps 3 sodium out for every 2 potassium in
creates concentration gradient conc. of sodium outside increasing
conc. K inside increasing
membrane is more permeable to K- so some leak out
result of these ionic movements is a potential gradient across the cell membranes
cell is negatively charged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is depolarisation

A

movement of ions across the membrane creates a change in the potential difference/ charge across the membrane
the inside of the cell becomes less negative compared to outside than usual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what causes an action potential to be initiated

A

larger stimulus so more gated channels will open
if enough are open then enough sodium ions enter the cell
potential difference changes significantly and will initiate an AP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is a myelinated neurone

A

has an individual layer of myelin around it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the myelin sheath composed of

A

schwann cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are nodes of ranvier

A

gaps in the myelin sheath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is a non-myelinated neurone

A

has no individual layer of myelin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what does a myelin sheath do

A

insulates myelinated neurones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

function of sensory neurone

A

carries an impulse from receptor to CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

structure of a sensory neurone

A

a long dendron
carry action potential from a sensory receptor to cell body
short axon carrying action potential into the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

function of a relay neurone

A

carries impulse from sensory neurone to motor neurone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

structure of a relay neurone

A

connects sensory to motor neurone
many short dendrites and a short axon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

function of a motor neurone

A

transmits impulse to the effector

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
structure of a motor neurones
cell body in the CNS long axon that carries the action potential to effector
26
structure of a cell body
nucleus many ER, mitochondria and ribosomes
27
structure and function of a dendron
extension from cell body transmits impulses towards cell body
28
structure and function of a dendrite
connects to other neurones carries impulses towards the cell body
29
structure and function of an axon
long nerve fibres transmits impulses away from cell body
30
what do neurones maintain a potential difference across
cell surface membrane/ plasma membrane
31
advantage of neurone structure
long - transmit action potential over a long distance many gated ion channels - control the entry of ions
32
define resting potential
the potential difference across the membrane whilst the neurone is at rest
33
how is resting potential established
Na+ ion gates fully closed K+ ion gates are leaky/ more permeable = inside is more negative sodium potassium pump pumps out 3Na+ ions and pumps in 2K+ ions using active transport so inside becomes more negative
34
what is resting potential at
-60mV
35
where does the exchange of Na+K happen in myelinated neurones
nodes of ranvier
36
how do you generate an action potential
higher conc. of Na+ outside the membrane some Na+ open = Na+ diffuse down the conc. gradient (membrane depolarises) if large enough = passes threshold = action potential caused voltage gated Na+ channels open depolarisation reaches +40mV inside the cell
37
stages of an action potential
membrane in resting state (polarised with -60mV inside) higher Na+ inside, higher K+ outside Na+ channels open = some Na+ diffuse into cell membrane depolarises = becomes less negative (threshold -50mV) positive feedback causes voltage gated Na+ ion channel to open more Na+ = inside more positive (+40mV) Na+ channels close and K+ open K+ diffuse out potential difference inside now negative (repolarisation) potential difference overshoots = cell hyperpolarised (-70mV) original resting potential restored (resting state)
38
explain how positive feedback works when an action potential is generated
when there is sufficiant generator potentials to reach threshold = more Na+ gated channels open
39
describe what the refractory period is
after an action potential = Na+ K+ are in the wrong places concentration of them is restored by the sodium potassium ion pump during this time another action potential cannot occur
40
what does the refractory period stop from happening
the action potential going in the wrong direction it keeps it going in one direction
41
how is an action potential moved down a neurone
local currents caused by Na+ cause depolarisation
42
describe how an action potential is moved down a neurone by local currents
when Na+ channels open and Na+ diffuse in Na+ diffuse sideways along neurone (away from the area of higher concentraion) this is the local current causes slight depolarisation further down causes Na+ voltage gated channels to open the open channels allow rapid influx of Na+ causes a full depolarisation
43
why doesn't an action potential reverse its direction
concentration of Na+ behind the action potential is still high
44
describe saltatory conduction
ionic movement only occurs at nodes of ranvier, cannot occur over myelin sheath Na+ diffuse along from nodes of ranvier to the next action potential jumps from one node to the next
45
advantages of saltatory conduction
conducts action potential more quickly
46
what is the all or nothing rule
an impulse/ action potential are all the same intensity and will all produce a depolarisation of -40mV
47
what is the significance of the frequency of transmission in an action potential
stimulus at higher intensity = more sodium channels are open in the sensory receptor = more generator potentials produced = more frequent action potentials produced
48
what is a cholinergic synapse
a synapse that uses acetylcholine as a neurotransmitter
49
what is a neurotransmitter
chemical used as a signalling molecule between two neurones in a synapse
50
what is a synapse
the junction between two or more neurones where they can communicate with/signal to each other
51
what is a synaptic cleft
gap between two neurones
52
structure of a cholinergic synapse
acetylcholine as neurotransmitter synaptic cleft between neurones
53
what is the pre synaptic bulb
the end of a pre synaptic neurone
54
features of a pre synaptic bulb
many mitochondria large amount of smooth endoplasmic reticulum - packages neurotransmitter into vesicles lots of vesicles voltage gated calcium ion channels
55
describe the post synaptic membrane
contains specialised sodium ion channels receptor that is specific to acetylcholine acetylcholine present in synaptic cleft = sodium ion gate opens
56
transmission across the synapse
action potential arrives at bulb voltage gated calcium ion channels open calcium ions diffuse into synaptic bulb calcium ions causes synaptic to move and fuse with pre synaptic membrane acetylcholine is released (exocytosis) diffuses across cleft binds to receptor sites on sodium ion channels in post synaptic membrane sodium ion gates open sodium ions diffuse into post synaptic membrane generator potential created new action potential created if above threshold
57
what is the role of acetylcholinesterase
enzyme in synaptic cleft that stops the transmission of signals by hydrolysing acetylcholine into ethanoic acid and choline (recycled into it) so no more action potentials continue to happen
58
how is neural communication an example of cell signalling
transmitter released by pre synaptic membrane and post synaptic neurone responds to it
59
what is summation
occurs when effects of several excitatory post synaptic potentials are added together
60
excitatory post synaptic potential
one action potential only causes a few vesicles to move on and fuse with pre synaptic membrane = few acetylcholine molecules diffuse across = small depolarisation = not sufficient to cause action potential in post synaptic neurone
61
inhibitory post synaptic potentials
an impulse which can reduce the effect of summation/ prevent an action potential in the post synaptic neurone
62
temporal summation
several action potentials in the same pre synaptic neurone
63
spatial summation
action potentials arriving from several different pre syanptic neurones
64
how can an action potential be transmitted to several parts of the nervous system
one pre synaptic neurone might diverge to several post synaptic neurones
65
explain what happens if we become habituated to stimulus
after repeated stimulation a synapse may run out of vesicles containing neurotransmitter = habituated to it

module 5 communication, homeostasis and energy (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions