lecture 8: nervous system Flashcards
1
Q
name the 2 parts of the nervous system
A
central nervous system (CNS)
peripheral nervous system (PNS)
2
Q
briefly describe CNS
A
brain
spinal cord
3
Q
briefly describe PNS
A
nerves (cranial and spinal)
ganglia (cluster of neuron cell bodies)
4
Q
cluster of cell bodies in CNS
A
nuclei
5
Q
name the 3 functions of nervous system
A
sensory input (PNS)
integration (CNS)
motor output (PNS)
6
Q
describe sensory input (PNS)
A
response to external and internal stimuli
7
Q
describe integration (CNS)
A
interpretation of sensory input
decides appropriate response
8
Q
describe motor output (PNS)
A
conduction of signals from the CNS to effector cells
9
Q
what are neurons
A
cells specialized for transmitting electrical and chemical signals
10
Q
name parts of a neuron
A
cell body
fiber like extensions
11
Q
what do the fiber like extensions of a neuron consist of
A
dendrites
axons
12
Q
describe dendrites
A
convey signals towards cell body
short and numerous
13
Q
describe axons
A
conduct impulses away from cell body
long single processes
some are insulated by myelin sheath
ends in axon terminal
14
Q
what do axon terminals do
A
relay signals to other cells by releasing neurotransmitters
form synapses (junctions) between pre-synaptic and post-synaptic neurons
15
Q
describe synapses
A
nerves communicate via synapses
neurotransmitter are release from pre-synaptic neuron and act on a post-synaptic neuron
16
Q
describe pathway (through neuron)
A
stimuli
dendrites
cell body
axon hillock
axon
axon terminal
synapse
dendrites
cell body
axon hillock
axon
axon terminals
synapse
effector
17
Q
describe synapse (channels)
A
neurotransmitters bind to ion channels on post synaptic dendrites and causes hyper (inhibitory) or de (excitatory) polarization
inhibitory - K+ moves out
excitatory - Na+ moves in
(2 separate ion channels)
18
Q
the time of response is dependent on what
A
speed of info transmission is dependent on number of synapses (number of neurons) in pathway
19
Q
describe nerves
A
PNS
nerve = many axons bundled together
20
Q
what is ganglion
A
PNS
all the axons synapsing
21
Q
name the 3 types of neurons
A
sensory
motor
interneuron (association neuron)
22
Q
describe sensory neurons
A
carry impulses from sensory receptors towards CNS
(afferent - towards)
cell bodies in PNS ganglia
23
Q
describe motor neurons
A
carry impulses from CNS to effectors
(efferent - leading away)
most cell bodies in CNS (except for some autonomic neurons)
24
Q
describe interneuron (association neuron)
A
connect sensory and motor neuron
shuttle signals through CNS pathways
99% of neurons
25
describe optice nerve/tract
optic nerve - pns
optic tract - cns
26
describe structure of spinal cord
bundles of axons emerge from the back (dorsal root) and front (ventral root) of the spinal
cord on either side and finger to form the spinal nerves
27
dorsal root contains
sensory neurons
28
ventral root contains
motor neurons
29
dorsal root ganglion contains
cell bodies of sensory neurons
30
name difference between brain and spinal cord (organization of matter)
spinal cord has grey matter in center
brain has grey matter as outer layer
31
describe flow of information through the nervous system
(ex withdrawal reflex)
receptor
sensory neuron
integration center (spinal cord)
motor neuron
effector
32
describe reflexes
involuntary response to stimuli (without conscious input)
33
what is a reflex arc
simple nerve circuit
34
why does doctor check your reflexes
gives info about health of nervous system
35
describe patellar reflex steps
receptor
sensory neuron
integration (spinal cord, few neurons, not complex)
motor neuron
effector
36
describe patellar reflex (generally)
2 neuron pathway BUT
also hamstrings must be relaxed for quads to contract
37
where are reflexes integrated
spinal cord and brain
38
name reflexes integrated in spinal cord
patellar reflex
withdraw reflex
39
name reflexes integrated in brain
involuntary
pupillary
swallowing
vomiting
breathing
blinking
sneezing
eyes tearing up
40
what are meninges
layers of connective tissues that cover the brain and spinal cord
41
name the 3 layers of meninges (and correct order outer to inner)
dura mater
arachnoid mater
pia mater
42
what is cerebral spinal fluid (CSF)
clear colourless fluid that surrounds brain and spinal cord
43
what contains CSF
ventricles - network of cavities within brain and spinal cord
44
name the functions of CSF
protection
buoyancy (1400g—>50g)
excretion of waste products
transport of hormones
45
what are glia
supporting cells
46
name the glial in CNS
astrocytes
oligodendrocytes
ependymal cells
microglial cells
47
describe astrocytes
provide structure and metabolic support
mediate exchange between capillaries and neurons and help form the blood brain barrier
48
describe oligodendrocytes
form myelin sheath around axons
49
describe ependymal cells
have cilia that beat to circulate CSF
line ventricles of brain and central canal of spinal cord
50
describe microglial cell
immune cell
51
name glia in PNS
schwann cells
52
describe schwann cells
form myelin sheath around axons
53
describe myelin sheath
formed by oligodendrocytes (CNS) or schwann cells (PNS)
waxy coating around axon of neuron
insulates axons
54
neurons can be…
myelinated
unmyelinated
55
what are nodes of ranvier
regions of axons without myelin
56
describe saltatory conduction
nerve impulse (action potential) jumps from
node of ranvier to node of ranvier so impulse moves faster
jumping from node to node in myelinated neurons = saltatory conduction
57
what is white matter
myelinated axons
58
what is grey matter
unmyelinated axons
cell bodies
dendrites
axon terminals
ALL synapsing
59
name effectors (pathway through neuron)
skeletal muscle
sweat glands
heart muscle
digestive smooth muscle
60
where are neurotransmitters released from (synapse)
axon terminal of presynaptic cell and act on postsynaptic cell
61
name organization of PNS anatomical (4)
cranial nerves
spinal nerves
ganglia
sensory receptors
62
describe cranial nerves
paired
info to and from brain
63
describe spinal nerves
paired
info to and from spinal cord
64
describe ganglia
cluster of neuronal cell bodies
65
describe sensory receptors
formed by dendrites of sensory neurons
66
name and describe (briefly) organization of PNS physiological
afferent (sensory) = towards CNS
efferent (motor) = away from CNS
67
describe efferent (motor) - organization of PNS (physiological)
somatic = skeletal muscle, voluntary (usually)
autonomic = smooth muscle, cardiac muscle, glands, involuntary
68
name and briefly describe divisions of autonomic nervous system
sympathetic = fight or flight
parasympathetic = rest and digest
69
describe ANS (autonomic nervous system)
parasympathetic and sympathetic divisions act on same targets but have opposing effects
70
which type of nerves is parasympathetic associated with (mostly involves)
cranial nerves
71
which type of nerves is sympathetic associated with (mostly involves)
spinal nerves
72
describe vagus nerve
cranial nerve in parasympathetic divining that does many things
73
what effects of parasympathetic nervous system is vagus nerve associated with
constricts bronchi in lungs
slows heart
stimulates activity of stomach and intestines
stimulates activity of pancreas
stimulates gallbladder
74
name all effects of parasympathetic division (9)
constricts pupil of eye
stimulates salivary gland secretion
constricts bronchi in lungs
slows heart
stimulates activity of stomach and intestines
stimulates activity of pancreas
stimulates gallbladder
promotes emptying of bladder
promotes erection of genitalia
75
name all effects of sympathetic division (10)
dilates pupil of eye
inhibits salivary gland secretion
relaxes bronchi in lungs
accelerates heart
inhibits activity of stomach and intestines
inhibits activity of pancreas
stimulates glucose release from liver; inhibits gallbladder
stimulates adrenal medulla
inhibits emptying of bladder
promotes ejaculation and vaginal contractions
76
TRUE OR FALSE: parasympathetic and sympathetic divisions ALWAYS have opposing effects
FALSEEEEE
they have a complementary effect =
para promotes erection of genitalia AND sym promotes ejaculation and vaginal contractions
77
where is body of post ganglionic neuron
in PNS ganglia
78
describe organization of somatic motor neurons in PNS
single motor neuron
releases acetylcholine (stimulates skeletal muscle to contract)
79
describe organization of sympathetic motor neurons in PNS
pre ganglionic neuron - releases acetylcholine
stimulates adrenal medulla to release epinephrine/norepinephrine into blood (acts as hormone)
OR
acts on post ganglionic neuron - releases norepinephrine (acts on effectors)
80
describe organization of parasympathetic motor neurons in PNS
pre ganglionic neuron - release acetylcholine (acts on post ganglionic neuron)
post ganglionic neuron - releases acetylcholine (acts on effectors)
81
name all neurotransmitters (5)
acetylcholine
norepinephrine
dopamine
serotonin
nitric oxide
82
describe acetylcholine (neurotransmitters)
skeletal muscle contraction
parasympathetic effects
83
describe norepinephrine (neurotransmitters)
sympathetic effects
84
describe dopamine (neurotransmitters)
affects sleep, mood, attention and learning
85
lack of dopamine in brain associated with
parkinson’s disease
86
excessive dopamine in brain associated with
schizophrenia
87
describe serotonin (neurotransmitters)
affects sleep, mood, attention and learning
88
describe nitric oxide (neurotransmitter)
acts as local regulator (ex: vasodilation by acting on smooth muscle)
89
what is brainstem and what’s it do
hindbrain + mid brain
relays info to and from higher brain centres
90
name the 3 parts of brainstem
medulla oblongata
pons
midbrain
91
describe medulla oblongata
contains nuclei that controls visceral functions (autonomic)
92
describe functions associated with medulla oblongata
breathing
heart rate
vasoconstriction and vasodilation
swallowing
vomiting
digestion
93
describe pons
contains nuclei that control visceral functions
ex = breathing
94
describe midbrain
contains nuclei for integration of sensory info
95
name 2 parts of midbrain and describe
superior colliculi = regulation of visual reflexes
inferior colliculi = regulation of auditory reflexes
96
name the main parts of brain
brainstem
reticular system
cerebellum
(epithalamus, thalamus and hypothalamus)
cerebrum
limbic system
97
describe reticular formation
diffuse set of neurons in brainstem
act as sensory filter to decide which info reaches cerebrum
98
what is RAS
reticular activating system (of reticular formation)
99
describe RAS
regulates sleeps and arousal
acts as sensory filter (important for sleep)
100
what does cerebellum do
coordinates motor activities with perpetual and cognitive factors
relays sensory info about joints, muscles, sight and sound to cerebrum
involved in coordination and balance
101
describe epithalamus
pineal gland - synthesizes melatonin
cluster of capillaries - produce CSF
102
describe thalamus
relays all sensory info (EXCEPT SMELL) to cerebrum
relays motor info from cerebrum
103
describe hypothalamus
regulates autonomic activity
regulates pituitary gland
thermoregulation, hunger, thirst, sexual and mating behaviour
104
what acts as biological clock for humans
suprachiasmatic nuclei (SCN) in hypothalamus
internal time keeper (circadian rhythm)
ex - controls release of melatonin from
pineal gland
105
describe cerebrum and name parts
most highly evolved structure of
mammalian brain
left hemisphere and right hemisphere
corpus callosum
basal nuclei
106
cerebrum is involved in
conscious thought
all voluntary actions
personality
107
describe left hemisphere (cerebrum)
responsible for right side of body
108
describe right hemisphere (cerebrum)
responsible for left side of body
109
describe corpus callosum (cerebrum)
major connection between left and right hemispheres
110
describe basal nuclei (cerebrum)
involve in major brain functions
ex = voluntary movement, cognition, emotions, habits, learning of procedures
111
describe cerebral cortex
outer covering of gray matter
consists of specialized regions with different functions
112
name the 4 lobes of cerebrum and their brief functions
frontal lobe = primary motor cortex
parietal lobe = primary somatosensory cortex
occipital lobe = vision
temporal lobe = hearing
113
what is broca’s area
speech production
left hemisphere
frontal lobe
114
what is wernickes area
speech comprehension
left hemisphere
temporal lobe
115
what is limbic system
mediates basic emotions like fear and anger
establishes emotional memory
116
what does limbic system consist of (6)
hippocampus
olfactory cortex
inner portions of cerebral cortex
thalamus
hypothalamus
amygdala
117
name the 2 types of memory
short term
long term
118
describe short term memory
stored in frontal lobes
119
describe long term memory
stored in different regions of brain depending on type
120
name and describe the 2 types of long term memory
explicit = memorization of facts that can be recounted
implicit = procedural, remembering how to do something, like riding bike
121
which type of long term memory takes longer to form
implicit
122
describe moving information from short term to long term memory
involves hippocampus
enhanced by repetition
influenced by emotional states mediated by amygdala (limbic system)
influenced by association with previously stored info
