Chapter 1 - General Plan of the Nervous System Flashcards
(51 cards)
1
Q
Nervous system divided based on anatomy/structure
A
- central nervous system (CNS) – brain and spinal cord
- peripheral nervous system (PNS) – cranial and spinal nerves
2
Q
Nervous system divided based on physiology/function
A
- somatic nervous system – controls body structures (voluntary)
- autonomic nervous system – controls smooth muscles, glands, blood vessels (involuntary)
3
Q
Spinal cord
A
connects brain and PNS
4
Q
Somatic nervous system
A
controls voluntary muscles and transmits sensory information to the CNS
5
Q
Autonomic nervous system
A
- controls involuntary body functions
- made up of sympathetic nervous system and parasympathetic nervous system (which are constantly competing to control arousal state)
6
Q
Sympathetic nervous system
A
arouses body to expend energy
7
Q
Parasympathetic nervous system
A
calms body to conserve and maintain energy
8
Q
Ventral, anterior
A
on the front (belly) side
9
Q
Dorsal, posterior
A
on the back side
10
Q
Superior
A
on the top (skull) side
11
Q
Inferior
A
on the lower side
12
Q
Caudal
A
in the lowermost position (at the tail end)
13
Q
Rostral
A
on the forward side (at the nose end)
14
Q
Medial
A
close to or toward the middle
15
Q
Median
A
in the middle, the midplane (midsagittal)
16
Q
Lateral
A
toward the side (away from the middle)
17
Q
Sagittal plane
A
- vertical line which divides the brain into a left section and a right section
- mid-sagittal is when brain is split right down the middle
- does not show bilateral symmetry
18
Q
Coronal plane
A
- vertical line which divides the brain into a front (anterior) section and a back (posterior) section
- shows bilateral symmetry
19
Q
Transverse/horizontal plane
A
- horizontal line which divides the body into an upper (superior) section and a lower (inferior) section
- horizontal plane is used for brain and transverse plane is used for spinal cord
- shows bilateral symmetry
20
Q
Central Nervous System (CNS)
A
- comprised of the brain (encephalon) and spinal cord
- brain has a tiered structure – 3 main subdivisions of the brain
- – cerebrum (forebrain) – most rostral
- – cerebellum
- – brain stem – most caudal
- each subdivision is further divided into discrete regions
21
Q
Cerebrum
A
- most phylogenically advanced
- responsible for complex functions (cognition)
- comprised of telencephalon and diencephalon
22
Q
Telencephalon
A
- comprised of:
- – cerebral cortex gray matter (neuron cell bodies)
- – subcortical white matter (myelinated axons going to and from cortex) (this includes corpus callosum)
- – commissures
- – basal ganglia (subcortical gray matter)
23
Q
Diencephalon
A
- comprised of:
- – thalamus
- – hypothalamus
- – epithalamus
- – subthalamus
24
Q
Cerebellum
A
- collections of gray matter and white matter tracts (2 lateral lobes joined by the vermis)
- comprised of cerebellar cortex and deep cerebellar nuclei
25
Brain stem
- collections of gray matter and white matter tracts
| - comprised of midbrain (mesencephalon), pons, and medulla oblongata
26
Ventricles
hollow spaces within the brain and spinal cord filled by cerebral spinal fluid (CSF)
27
Spinal cord - neuronal somata (cell bodies) and tracts
- neuron cell bodies lie in the center of the spinal cord in an area called the Central Gray (gray matter)
- connections (or pathways) between neurons in CNS exist as fiber bundles or tracts (white matter)
- -- aggregates of tracts in the spinal cord are called columns
28
Gray matter
contains neuronal and glial cell bodies, axons, dendrites, and synapses
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White matter
contains myelinated axons and associated glial cells
30
Tracts and commissures in brain and spinal cord
- connections/pathways between neurons in CNS exist as fiber bundles or tracts called fasciculi
- -- aggregates of fasciculi in the spinal cord are called columns
- -- vertical pathways may remain on the same side (ipsilateral) or cross (decussate) to the opposite side (contralateral)
31
Ipsilateral
on the same side
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Contralateral
on the opposite side
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Bilateral
on both sides
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Symmetry of the Nervous System
- nervous system is bilaterally symmetrical
- -- organized into left and right hemispheres
- -- some functions are unilaterally strong (e.g. language in the left hemisphere)
35
Functional maps exist within the brain
- at many levels, the brain maps the outside world
- -- e.g. sensory and motor homunculous (sensory and motor neural representation of the body surface)
- -- topographically faithful map
- ----- body relationships preserved
- ----- size of part reflects disproportional sensitivity
36
Peripheral Nervous System (PNS)
- spinal nerves, cranial nerves, and ganglia (collections of cell bodies) outside of the CNS
- PNS nerve fibers conduct information to (afferent) or from (efferent) the CNS
- peripheral nerves connect to spinal cord by dorsal (sensory) and ventral (motor) roots
37
Spinal nerves branch off from the spinal cord
each nerve is split into dorsal and ventral nerve roots
38
Dorsal roots
sensory
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Ventral roots
motor
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D.S.A.
dorsal sensory afferent
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V.M.E.
ventral motor efferent
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Afferent
to
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Efferent
from
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Longitudinal axes of CNS
- longitudinal axis of brain stem and spinal cord
| - longitudinal axis of forebrain
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Ventral side of brain
underside of brain
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Dorsal side of brain
overside of brain
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Ventral side of spinal cord
side towards nose
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Dorsal side of spinal cord
side towards back of head
49
Rostral end of spinal cord
end towards brainstem
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Caudal end of spinal cord
end towards bottom of the spinal cord
51
ependymal cells
- produce and absorb CSF
