The Nervous System Flashcards
1
Q
what is the basic route a reflex takes through the nervous system?
A
stimulus —> receptor (sense organs) —> coordination (nervous system) —> effector (muscles/glands) —> response
2
Q
if the stimulus is light what is the receptor?
A
eye
3
Q
if the stimulous is sound or balance, what is the receptor?
A
ear
4
Q
if the stimulus is smell, what is the receptor?
A
nose
5
Q
if the stimulus is taste, what is the receptor?
A
tongue
6
Q
if the stimulus is touch, pain, temperature or pressure, what is the receptor?
A
skin
7
Q
what are the sense organs (receptors)
A
eyes
ears
nears
tongue
skin
8
Q
what is in the central nervous system?
A
brain
spinal cord
(optic nerve)
9
Q
what is in the peripheral nervous system?
A
nerves outside the CNS
10
Q
what are the effectors?
A
muscle
glands
11
Q
effector
A
an organ (muscle or gland) that brings about a response
12
Q
nervous system
A
the vast network of nerves in the body
13
Q
receptor cell
A
a cell that senses a stimulus and transmits the message along
14
Q
stimulus
A
a detectable change in the environment
15
Q
response
A
a change brought about following a stimulus
16
Q
central nervous system (CNS)
A
the part of the nervous system that includes the brain, optic nerves and spinal cord
17
Q
sense organ
A
a specialised organ with clusters of receptor cells that sense a change in the environment
18
Q
brain
A
the control centre of the CNS
19
Q
spinal cord
A
a bundle of nerves enclosed in the spine that connects neraly all parts of the body to the brain
20
Q
reflex
A
involuntary and almost immediate response to a stimulus
21
Q
neurone
A
(nerve cells)
specialised cells which transmits information through nerve impulses
22
Q
nerve
A
(nerve cell = a single neuron)
a bundle of several neurones
23
Q
nerve impulses
A
electrical sugnal (current) that travels along a neurone
24
Q
where is the motor neurone
A
in the peripheral nervous system
25
where is the sensory neurone
in the peripheral nervous system
26
where is the relay neurone
in the central nervous system
27
label this motor neurone diagram
28
label this sensory neurone diagram
29
label this relay neurone diagram
30
which neurone is this
sensory neurone
31
which neurone is this
relay neurone
32
which neurone is this
motor neurone
33
cell body
the oart of the neurone which contains the nucleus
34
dentrites
extensiones at which nerve impulses are recieved from other cells at synapses and transmitted to the cell body
35
axon
extension which carried nerve impulses to other neurone or effector organ (muscle or gland)
36
myelin sheath
faty sheath which insulates the axon (preventing short-circuits of electrical impulses) and speeds up the conduction of nerve impulses; made of Shwann cells
37
reflex arc
the pathway through the nervous system that a reflex takes
38
what is the order of the reflex arc
stimulus ---\> receptor ---\> sensory neurone ---\> relay neurone (CNS) ---\> motor neurone ---\> effector ---\> response
sensory neurone, relay neurone, motor neurone = coordination
39
label this reflex arc diagram
40
label this spinal cord diagram
41
what is the spinal cord made up of
long, thin, tubular bundle of nerves
42
what is the spinal cord enclosed by
vetebral column
43
the spinal cord is an extension of .... from the ....
the spinal cord is an extension of the **central nervous system (CNS)** from the **brain **
44
how quickly does the transmitting of the nerve impulses happen?
can happn in 1/30 of a second
45
reflexes are ... responses, i.e. you don't need to ... about them
generally, the brain is not ... in coordinating a reflex
exception: the brain is actively ... where the ... is located in the ... rather than the spinal cord (e.g. ...)
the brain is ... about a stimulus/reflec happening (e.g. ... reflex after touching a hot plate, the brain is informed about the ... this causes)
the brain can decide to ... a reflex (e.g. you can prevent a ... reflex when touching a hot plate, if you don't want to ... it)
reflexes are **unconscious/involuntary** responses, i.e. you don't need to **think** about them
generally, the brain is not **involved** in coordinating a reflex
exception: the brain is actively **involved** where the **relay neurone **is located in the **brain** rather than the spinal cord (e.g.** pupil reflex**)
the brain is **informed** about a stimulus/reflec happening (e.g. **withdrawl** reflex after touching a hot plate, the brain is informed about the **pain**this causes)
the brain can decide to **override** a reflex (e.g. you can prevent a **withdrawl** reflex when touching a hot plate, if you don't want to **drop **it)
46
do you have beter or worse balance when your eyes are open?
better
47
when your centre of balance is titled do your muscle reflexes act slower or faster
faster
48
name two mai parts of the central nervous system
spinal cord
brain
49
describe how information from receptors in the nervous system is passed to the CNS
the receptors in the sense organs transmit a signal to the muscle via nerve impulses through the sensory neurone to the relay neurone in the central nervous sysetm
50
which organ controls the nervous system?
the brain
51
what are some examples of a reflex action
snatching your hand form a hot object
knee-knock
blinking
coughing
52
label this reflex arc diagram
53
give three receptors which a mouse might use to detect food under natural conditions
see the food with eyeys
touch with mouse paws
smell with nose
54
describe how a mouse respons to a dropped pen
the mouse hears the pen drop (stimulus)
the dendrites in the sensory neurones in the peripheral nervous system are activated by the receptor cells and transmit a signal through the dendron and axon (along with myelin sheath)
this nerve impulse gets transmitted ino the central nervous sysem and intor the relay neurones and through the motor neurone
this activated the mouse's muscles which moves and the repsonse is to run away
this is called the reflex arc which is the pathway through the nervous system that a reflex takes
it takes 1/30 of a second
55
synapses
tiny gap between two neurons across which impulses pass by diffusion of a neurotransmitter
56
neurotransmitter
chmical that passes on a sinal from one neurone to another across a synapse
57
give examples of a neurotransmitter
amino acids
dopamine
adrenaline
58
label this diagram of a nerve impulse through a synapse
59
what is step 1 of transmission of a nerve impulse across a synapse?
the nerve impulse travels along the axon to the synapse in form of an electrical signal
60
what is step 2 of transmission of a nerve impulse across a synapse?
the vesicles containing neurotransmitter move to the membrane
61
what is step 3 of transmission of a nerve impulse across a synapse?
the neurotransmitter is emptied into the space between neurone (synapse)
62
what is step 4 of transmission of a nerve impulse across a synapse?
the neurotransmitter diffuses across the synapses (from high to low concentration)
63
what is step 5 of transmission of a nerve impulse across a synapse?
the nuerotransmitter binds to the receptors on the surface of the dendrite
64
what is step 6 of transmission of a nerve impulse across a synapse?
binding of the neurotransmitter triggers a new nerve impulse
65
what is step 7 of transmission of a nerve impulse across a synapse?
the nerve impulse travels from the dendrite to the axon
66
How is a nerve impulse transmitted across a synapse (all the steps together)?
**step 1:** the nerve impulse travels along the axon to the synapse in form of an electrical signal
**step 2:** the vesicles containing neurotransmitter move to the membrane
**step 3:** the neurotransmitter is emptied into the space between neurone (synapse)
**step 4:** the neurotransmitter diffuses across the synapses (from high to low concentration)
**step 5:** the neurotransmitter binds to the receptors on the surface of the dendrite
**step 6:** binding of the neurotransmitter triggers a new nerve impulse
**step 7:** the nerve impulse travels from the dendrite to the axon
67
what is a disease or condition linked to a defective neurotransmitter function
Parkinson's
68
label this eye
69
label this structure of the eye
70
conjunctiva
= layer covering the cornea and sclera
helps to lubricate the eye
71
cornea
= clear covering of eye
helps to refract amd focus on light
72
lens
= transparent structure behind pupil
refracts and focuses on light
73
pupils
= hole in centre of iris
controls amount of light entering eye
74
iris
= pigmented tissue, sphincter
controls amount of light entering eye
75
suspenory ligaments
= ligaments connecting ciliary muscle and lens
involved in controlling accomodation (focusing)
76
ciliary muscle
= ring of muscle connected to lens via suspensory ligaments
controls accomodation (focusing)
77
retina
= inner layer of eye containing rods + cone
responds to light stimulus
78
optic nerve
= sensory nerve (part of CNS)
carries nerve impulses from retina to brain
79
in the pupil reflex, which is the:
receptor
sensory nerve
effector
receptor = retina
sensory nerve = optic nerve
effector = muscles in the iris
80
label this diagram of an eye
81
what happens to the pupil reflex in dim light
radial muscles contract
circular muscles constrict
pupil dilates
82
what happens to the pupil reflex in bright light?
radial muscles relax
circular muscles contract
pupil constricts
83
in the dark a ... action occurs: the ... gets larger so that more ...can enter the eye and you can see
the oppotite happens in bright light: the ... gets smaller and this stops too much ... entering the eye and ... it
the changes in the ... are controlled by muscles in the ...
when the pupil contracts (in ... light), the ... muscles contracted and the ... muscles are relaxed
when the pupil dilates (in ... light), the ... muscles are contracted and the ... muscles are relaxed
in the dark a **reflex** action occurs: the **pupils** gets larger so that more **light** can enter the eye and you can see
the oppotite happens in bright light: the **pupils** gets smaller and this stops too much **light** entering the eye and **damaging** it
the changes in the **pupil** are controlled by muscles in the **iris**
when the pupil contracts (in **bright** light), the **circular** muscles contracted and the **radial** muscles are relaxed
when the pupil dilates (in **dim** light), the **radial** muscles are contracted and the **circular** muscles are relaxed
84
label this struture of the retina diagram
85
what are the two photoreceptors?
rods
cones
86
what are rods sensitive to?
dim light vision
87
what are cones sensitive to?
colour vision: blue, red, green
88
what is monochromacy
total colour blindness
89
what is anomalous trichomacy
red-green blindness
90
what is night blindness
when rods don't respond to light
91
our retinas our covered with light sensitive cells called ... and ...
the ... detect the intensity of light and allows us to see if things are bright or dark
the ... detect colour. when there is little light, the ... do not work so we find it difficult to tell what ... things are
there are ... types of cone cells in the retina
each type is sensitive to a different colour of light: ..., ... or ...
our retinas our covered with light sensitive cells called **rods** and **cones**
the **rods** detect the intensity of light and allows us to see if things are bright or dark
the **cones** detect colour. when there is little light, the **cones** do not work so we find it difficult to tell what ... things are
there are **three** types of cone cells in the retina
each type is sensitive to a different colour of light: **red** , **blue**, or **green**
92
accommodation
the reflex that makes the eye focus on an object by changing he shape on its lens
93
light reflected from an object is ... (bent) by the ... and the ... forming an upside down image on the ...
the ... interprets this image so that it appears upright to us
the lens ... is adjustable and so can bend light more or less, thus allowing the eye to ... on an object at different distances
light reflected from an object is **refracted** (bent) by the **cornea** and the **lens** forming an upside down image on the **retina**
the **brain** interprets this image so that it appears upright to us
the lens **shape** is adjustable and so can bend light more or less, thus allowing the eye to **focus** on an object at different distances
94
describe how nearby objects appear when focusing on a distant object and why
light rays from a nearby object come into the eye at an angle
if they are not refrcted enough the object will look blurry
95
describe how distant objects appear when focusing on a distant object and why
light rays from a distant object arrive at the eye nearly parallael
when the eye focuses on a distant object the lens is flatter so that the light rays retract less
96
describe how nearby objects appear when focusing on a nearby object and why
to focus on a nearby object the lens becomes rounder (more convex) so that light rats are refracted more
97
describe how distant object appear when focusing ona nearby object and why
the light rays from a distant object are refracted too much so that the object will look blurry
98
label this mechanism of accommodation diagram for focusing on a nearby object
99
label this mechanism of accommodation diagram for focusing on a distant object
100
explain how a reflex arc helps withdrawla finger from a hot plate
a reflex arc is the pathway trhough the nervous sysetm a reflex takes
a detectable change in the environment (stimulus) is sensed by your skin, the receptor (sense organ), and this transmits a nerve impulse through the sesory neurone in the peripheral nervous system
the peripheral nervous system picks up the impulse by its dentrites and transmits the signal along the axon where it is recieved by the dendrites of the relayneurone in the CNS and trasmitted along its axon where it is recieved by the dendrites on the motor neurone in the peripheral nervous system along its axon where an arm muscle (effectro) recieves the impulse which tells us to withdra our finger from the hotplate (response)
the reflex is involuntary and almost immediate so we don't get burnt
101
give a reflex to the action that occurs in our in dim light
we can adjust our vision to see in dim light
102
what is the name of neurone A?
sensory neurone
103
what is the name of the microscopic gap between B and C?
104
name X and Y on neurone C
X = nucleus
Y = myelin sheath
105
which neurone passes impulses from a receptor to the CNS
sensory neurone
B
106
which neurone is found only in the CNS
a relay neurone
A
