Module 5 Flashcards
1
Q
Three functions of the nervous system
A
sensory input
integration
motor output
2
Q
what is integration? Where does it occur?
A
- incorporates multiple simultaneous signals
- occurs in the brain or spinal cord
3
Q
what are the two subdivisions of the nervous system
A
- Central Nervous System (CNS)
2. Peripheral Nervous System (PNS)
4
Q
the brain and spinal cord are apart of which subdivision of the nervous system
A
central nervous system (CNS)
5
Q
cranial nerves, spinal nerves, autonomic nervous system, special sense organs are apart of what subdivision of the nervous system
A
Peripheral nervous system (PNS)
6
Q
what do efferent neurons do?
A
carry signals AWAY from the CNS
7
Q
what do afferent neurons do?
A
carry signals TOWARDS the CNS
8
Q
what are the two principle cell types of the nervous system
A
- neurons
2. supporting cells
9
Q
Neurons
A
- excitable
- transmit rapid electrical signals to other neurons
10
Q
what are the three parts of a neuron’s structure
A
- cell body
- dendrites
- axon
11
Q
what are the cytoplasmic processes
A
dendrites and the axon
12
Q
what is another name for the cell body
A
soma
13
Q
what does the cell body do?
A
houses the nucleus and other organelles. Functions to transfer electrical signals from the dendrites to the axon
14
Q
what do the dendrites do?
A
receive the neuronal signal from other neurons and transfer those signals to the cell body
15
Q
what is the axon?
A
only ONE per neuron. Carry the signal from the cell body to the axon terminals, where the signal is then transferred to other neurons or organs
16
Q
a nerve impulse is _______
A
unidirectional (only occurs in one direction)
17
Q
what is the order that a nerve impulse moves through a neuron
A
dendrites - cell body - axon - dendrites of adjacent neurons OR target organs
18
Q
how are neurons classified ?
A
based on the number of cellular processes (dendrites and axon) that extend from the cell body
19
Q
Pseudounipolar neurons
A
one cellular process that splits into a dendrite and an axon (general sensory nerves)
20
Q
Bipolar nerves
A
one dendrite and one axon, two distinct cellular processes (found in special senses like sight and hearing)
21
Q
multipolar nerves
A
multiple dendrites and one axon, three or more cellular processes, number of dendrites is variable (motor neurons)
22
Q
another name for supporting cells
A
neuroglia (or glia)
23
Q
what is the function of supporting cells?
A
to protect and support neurons, as well as aid in sending signals between neurons to improve communication
24
Q
what are the four supporting cells of the CNS
A
- Astrocytes
- Microglia
- Ependymal
- Oligodendrocytes
25
Astrocytes
- large, star-shaped cells with numerous processes
26
function of astrocytes
communicate with neurons and blood vessels to maintain the integrity of the neural tissue
27
which of the glial cell sin the CNS is the most abundant?
Astrocytes
28
Microglia
- perform many protective functions in the CNS
| - able to phagocytose (engulf and destroy other cells)
29
what shape is ependymal?
simple cuboidal
30
where is ependymal found?
lines the cavities of the brain and spinal cord
31
which supporting cell assists int he production, circulation and monitoring of cerebrospinal fluid (CSF)?
Ependymal
32
Oligodendrocytes
- wrap around axons in the CNS to form myelin sheath
| - a single cell can myelinate up to 60 axons
33
what is myelin made up of?
mainly fat, appears white
34
purpose of myelin?
insulates the axon and increases the speed electrical signals can travel down the axon
35
neurofibril nodes are what?
unmyelinated regions
36
What are the supporting cells of the PNS called?
SCHWANN CELLS
37
what are Schwann cells?
equivalent to the Oligodendrocytes in that they form the myelin sheath around axons in the PNS
38
A single Schwann cell...
can only myelinate a portion of one axon, as they don't have processes like oligodendrocytes
39
the cerebrum is made up of what two parts?
Diencephalon and Telencephalon
40
Diencephalon
- deep to the telencephalon
- responsible for sensory and motor relay into and out of the brain
- controls the autonomic nervous system
41
what are the two components of the diencephalon?
hypothalamus and the thalamus
42
what does the hypothalamus do?
controls the release of hormones
43
where is the hypothalamus located?
- small structure below the thalamus
| - connected to the pituitary gland
44
structure of the thalamus?
- deep brain structure
| - two bodies (one per hemisphere)
45
responsibilities of the thalamus
relaying sensory information to other areas of the brain (except smell)
46
Telencephalon
- bulk of the cerebrum
| - responsible for interpreting sensory signals, sending out motor signals and decision making
47
What are the components of the Telencephalon?
- cerebral hemispheres
- cerebral cortex
- sulci and gyri
- lobes of the cerebrum
- grey matter
- white matter
48
what separated the two cerebral hemispheres
the longitudinal fissure
49
cerebral cortex
- outer layer of cerebrum
| - distinguished by dark grey colour
50
what is the purpose of the sulci and gyri?
increase the surface area of neural tissue, which increases functional capacity
51
SULCI
fissures/grooves
52
GYRI
lumps/bumps between sulci
53
what is the cerebral cortex? How is it distinguished?
- outer layer of cerebrum
| - distinguished by its dark grey colour
54
what are the four lobes of the cerebrum?
- frontal
- parietal
- occipital
- temporal
55
what does the central sulcus boundary separate
frontal lobe and parietal lobe (i.e motor cortex and sensory cortex)
56
where is the precentral sulcus ?
anterior border of motor cortex
57
where is the postcentral sulcus?
posterior border of sensory cortex
58
where is the parieto-occipital sulcus ?
separates the parietal and occipital lobes
59
what does the lateral sulcus separate?
temporal lobe and frontal/parietal lobe
60
what is the precentral gyrus responsibile for?
sending motor output signals
61
what is the postcentral gyrus responsible for ?
receiving sensory input related to touch and feel
62
which of the specific gyri is posterior?? anterior?
precentral gyrus = anterior
| postcentral gyrus = posterior
63
what is grey matter made up of?
groups of cell bodies of neurons
64
what parts of the brain is grey matter in?
in the cerebral cortex and inner areas of the brain
65
what is white matter made up of?
the axons of neurons (myelinated axons are white)
66
function of white matter?
makes up communication tracts that connect different areas of the brain and spinal cord
67
What three fibers are found in the white matter of the brain?
- association fibers
- commissural fibers
- projection fibers
68
Association fibers?
communication within one hemisphere
69
commissural fibers?
communication between two hemispheres (EX: corpus callosum)
70
projection fibers
communication between different levels of the CNS (I.E between brain and spinal cord)
71
where is the brainstem located?
just below the diencephalon
72
brainstem
- connects brain to spinal cord
| - contains many autonomic reflex centers and white matter tracts necessary for human functioning and survival
73
what are the three components of the brain stem?
- midbrain
- pons
- medulla oblongata
74
midbrain
- most superior aspect of brainstem
- anteriorly: large white matter tracts that make up the cerebral peduncles
- postero-lateral: two pairs of raised bumps (colliculi)
75
where is the pons located?
- middle of brainstem, behind the 4th ventricle and in front of the cerebellum
76
purpose of the pons
has fibers connecting it to the cerebellum
| - COMMUNICATION
77
Medulla Oblongata
- most inferior of brainstem
| - continuous with the spinal cord
78
where is the cerebellum located?
- appended to the back of the brainstem
| - sits underneath the occipital lobe of the cerebrum
79
function of the cerebellum?
coordinates motor activity
80
what are meninges?
three connective tissue membranes protecting the structures of the CNS
81
what are the three meninges that support and protect the brain?
- dura mater
- arachnoid mater
- pia mater
82
what is the dura mater of the brain composed of?
double layer of connective tissue that attaches firmly to the skull
83
arachnoid mater of the brain
- loosely covers the brain
| - creates an area called the sub-arachnoid space, filled with cerebrospinal fluid and blood vessels
84
pia mater of the brain
attached firmly to the cerebral cortex
85
what are the ventricles of the brain?
four hollow spaces that are continuous with eachother and the spinal cord
86
what do the ventricles do?
produce csf that protects the brain from sudden movements and its own weight
87
what are the lateral ventricles?
paired "c" shaped spaces deep within the cerebral hemispheres
88
what are the four components of the lateral venricles and what lobes of the brain are they in?
anterior horn: frontal lobe
inferior horn: temporal lobe
posterior horn: occipital lobe
body: parietal lobe
89
where is the third ventricle?
- located in the middle of the diencephalon between the two halves of the thalamus
90
where is the fourth ventricle?
- sits between the pons/medulla and the cerebellum
91
what connects the third and fourth ventricles?
the cerebral aqueduct
92
what connects the third ventricle with the lateral ventricles?
by the interventricular foramina
93
the fourth ventricle is continuous with what?
the central spinal cord and the subarachnoid space
94
what is order in which CSF flows?
1. lateral ventricles
2. interventricular foramen
3. third ventricle
4. cerebral aqueduct
5. fourth ventricle
6. vertebral column
95
what protects the spinal cord?
vertebral canal
96
what does the spinal cord do?
facilitates communication between the CNS and the PNS
97
where does the spinal cord start?
foramen magnum
98
what is L2 of the spinal cord?
conus medullaris
99
what are the axons below L2 called?
the axons emerging from the spinal cord below L2 are called cauda equina
100
within the cauda equina?
a small thin strand of pia mater anchors the spinal cord to the sacrum, known as the filum terminale
101
what is the conus medullaris?
L2 of the spinal cord
102
What is the foramen magnum?
where the spinal cord begins
103
what is the the small thin strand of pia mater that anchors the spinal cord to the sacrum called?
the filum terminale
104
what are the four regions of the spinal cord from top to bottom?
1. cervical
2. thoracic
3. lumbar
4. sacral
105
what is the reason for spinal enlargements?
- the additional nerves in those areas needed to supply the LIMBS
106
what are the two spinal enlargements?
cervical - upper limb
| lumbar - lower limb
107
how is the dura mater different between the brain and spinal cord?
dura mater in spinal cord is made of only one layer of connective tissue whereas the brain has two layers
108
what is between the external surface of the spinal cord and the bone?
fat-filled epidural space
109
the subarachnoid space of the spinal cord is continuous with the subarachnoid space of the brain and contains what?
cerebrospinal fluid
110
the pia mater of the spinal cord is directly attached to what?
the spinal cord
111
how is the white/grey matter of the spinal cord different from the brain?
opposite - inner grey matter, outer white matter
112
what three horns are found in the grey matter of the spinal cord
```
ventral horn (anterior) - carries motor info
lateral/intermediate horn - carries info from sympathetic nervous system
dorsal horn (posterior) - carries sensory info
```
113
what does the white matter of the spinal cord consist of?
tracts of fibers separated into anterior, lateral, and posterior funiculi (bundles)
