M2 Study Guide Flashcards
(215 cards)
1
Q
afferent
A
to CNS
sensory
2
Q
efferent
A
away from CNS
motor
3
Q
what does the proencephalon (forebrain) consist of
A
telencephalon (cerebrum)
- olfactory (CN I): sensory only
4
Q
what does the diencephalon (deep brain and hypothalamus, thalamus, and epithalamus) consist of
A
optic (CN II): sensory only
5
Q
what does the rhombencephalon (hindbrain) consist of
A
metencephalon (pons)
myelencephalon (medulla)
5
Q
what does the mesencephalon (midbrain) consist of
A
oculomotor (CN III): motor only
trochlear (IV): motor only
5
Q
what does the myelencephalon (medulla) consist of
A
vestibulocochlear (VIII): sensory.
glossopharyngeal (IX): mixed.
vagus (X): mixed.
spinal accessory (XI): motor.
hypoglossal (XII): motor.
5
Q
what does the metencephalon consist of
A
Trigeminal (V): mixed.
- ophthalmic (V1): sensory
- maxillary (V2): sensory
- mandibular (V3): mixed
abducens (VI): motor
facial (VII): mixed
5
Q
what is the midbrain
A
connector between forebrain and hindbrain
6
Q
what type of fibers does CN I have
A
sensory only (SVA)
6
Q
sensory ganglia of the head
A
trigeminal (V)
geniculate (VII)
6
Q
are autonomic ganglia of the head sympathetic or parasympathetic
A
parasympathetic because the ganglion for sympathetic innervation to the head and neck is located in the thorax as the superior-most ganglion of the sympathetic trunk = superior cervical ganglion
6
Q
what are the autonomic ganglia of the head and what do they innervate
A
Ciliary (CN III):
- pupil constriction (miosis)
- accommodation (increased focusing ability of eye).
Pterygopalatine (VII):
- lacrimal and glands in nasal cavity and maxillary sinus (increased secretion).
Submandibular (VII):
- submandibular and sublingual salivary glands (increased secretion).
Otic (IX):
- parotid salivary gland (increased secretion).
6
Q
what can happen to CN I following trauma
A
can be sheared by olfactory foramen.
ex. acceleration-deceleration such as automobile collisions
7
Q
location of olfactory bulb
A
rests on cribriform plate of ethmoid within anterior cranial fossa
7
Q
where do CN I rootlets enter
A
anterior cranial fossa via olfactory foramina within cribriform plate of ethmoid
7
Q
where do the olfactory tracts from bulb project
A
telencephalon
ex. cerebrum
8
Q
what fibers is CN II
A
sensory only (SA)
9
Q
what is the optic nerve comprised of
A
retinal ganglion cells (RGCs) surrounded by meninges, so there are some CNS characteristics
10
Q
where does the optic nerve exit orbit
A
via optic canal in the middle cranial fossa above cavernous sinus
11
Q
where does the optic nerve go after passing through the optic chiasm
A
project to lateral geniculate bodies (as optic tract), which are located within thalamus of diencephalon
12
Q
what fibers are CN III (oculomotor nerve)
A
motor only.
GSE.
GVE
13
Q
what is innervated by CN III
A
extraocular muscles:
- superior rectus
- inferior rectus
- medial rectus
- inferior oblique
14
Q
where does CN III carry autonomic input to
A
carries GVE to iris sphincter muscle for pupil constriction and ciliary muscle for accommodation via ciliary ganglion (autonomic ganglion for CN III)
15
explain the "down and out" eye appearance in complete oculomotor palsy
superior oblique and lateral rectus are not affected because they are innervated by trochlear and abducens nerves, so the opposing muscles pull the eye "down" and "out".
pupils may be affected: mydriasis - dilated pupil - as result of loss of pupillary constrictor muscle function as parasympathetic preganglionic fibers 'ride' along outside oculomotor nerve.
aneurysms of internal carotid artery in cavernous sinus typically associated with oculomotor palsies.
16
what does CN III emerge from and pass through
emerges from midbrain (mesencephalon), passes through cavernous sinus within middle cranial fossa and into orbit via superior orbital fissure (SOF).
17
what fiber is CN IV (trochlear nerve)
motor only.
GSE
18
what does CN IV innervate
extraocular muscle: superior oblique
19
pathway of CN IV
emerges from midbrain, passes through cavernous sinus and exits middle cranial fossa into orbit via SOF
20
what fibers are CN V (trigeminal nerve)
mixed.
GSA
SVE
21
what occurs secondary to reactivation of herpes zoster virus
herpes zoster ophthalmicus
22
hutchinson's sign
vesicles at tip of nose, which is innervated by a branch of V1
23
assessing CN V clinically
CN V1: supraorbital nerve --> brach of frontal nerve of V1.
CN V2: infraorbital nerve.
CN V3: mental nerve --> branch of inferior alveolar nerve of V3.
24
main branches of the sensory division (GSA) of CN V V1
lacrimal
frontal
nasociliary
25
sensory innervation the sensory division of of CN V V1
eye and orbit
facial skin above orbits
midline region of nose to tip
26
pathway of CN V V2
enters middle cranial fossa from pterygopalatine fossa via foramen rotundum then passes through cavernous sinus to the pons
27
main branches of CN V V2
zygomatic (lateral wall of orbit) and infraorbital (runs from surface of cheek through maxilla and enters floor of orbit) pass through inferior orbital fissure into pterygopalatine fossa where it becomes maxillary
28
sensory innervation of CN V V2
facial skin below orbits and above mouth and lateral to orbit.
maxillary sinus - located within maxilla
29
what type of nerve is CN V V3
mixed nerve
30
motor innervation of CN V V3
major muscles of mastication (SVE):
- masseter
- temporalis
- medial pterygoid
- lateral pterygoid
31
sensory innervation of CN V V3
area from below mouth arcing lateral and upward to just anterior of external ear.
nasal cavity.
anterior 2/3s of tongue (lingual nerve).
all are GSE
32
lingual nerve
runs next to autonomic fibers from chorda tympani to the submandibular ganglion
33
what is the mental nerve a branch of
inferior alveolar nerve
34
what is the inferior alveolar nerve typically evaluated for
CN V V3 integrity during cranial nerve testing
35
what does CN V V3 exit/enter and pass through
exits/enters middle cranial fossa via foramen ovale but does NOT pass through cavernous sinus because ovale is in the FLOOR of middle cranial fossa BELOW cavernous sinus
36
what fibers is CN VI (abducens)
motor only.
GSE
37
what muscle is innervated by CN VI (abducens)
extraocular muscle: lateral rectus
38
what does CN VI palsy result in
loss of abduction - eye cannot turn outward
39
what does CN VI emerge from and pass through
emerges from pons.
passes through cavernous sinus and into the orbit via superior orbital fissure
40
what does CN VI pass over after emerging from the CNS and into the middle cranial fossa
passes over sharp-edged petrous portion of the temporal bone which makes this CN more susceptible to injury/damage from a head injury, or certain medical conditions like diabetes
41
what nerve fibers make up CN VII (facial)
mixed nerve.
GSA
SVA
GVE
SVE
42
where do CN VII nuclei lie
within the pons near those for CN VI
43
where does CN VII enter/exit
exits/enters posterior cranial fossa via internal acoustic (auditory) meatus and eventually exits skull at stylomastoid foramen (between styloid and mastoid processes of temporal bone)
44
what root does CN VII contain
large motor and smaller intermediate (sensory and autonomic) root
45
major motor root branches of CN VII and what they control
Stapedial: controls amplitude of sound waves to inner ear by preventing excess movement of one of the ear ossicles (stapes).
Posterior auricular: motor to occipital muscle on back of head.
Two motor branches to stylohyoid and posterior belly of digastric muscles (aids in swallowing).
Terminal branches: 5 motor branches to muscles of facial expression - from superior to inferior:
- temporal
- sygomatic
- buccal
- mandibular
- cervical
46
major intermediate (sensory and autonomic) root branches of CN VII
Chorda tympani (GVE and SVA fibers).
Greater petrosal nerve (GVE)
47
GVE innervation of chorda tympani
autonomic innervation to submandibular and sublingual glands via submandibular ganglion and alongside lingual nerve, a sensory branch of CN V V3
48
SVA innervation of chorda tympani
sensory innervation for taste from anterior 2/3rds of tongue.
first run alongside lingual nerve before chorda tympani
49
what axons does the greater petrosal nerve contain and where do they originate
contains preganglionic parasympathetic axons.
originates at geniculate ganglion and passes into the middle cranial fossa --> joins with deep petrosal nerve
50
what axons does the deep petrosal nerve contain and where do they come from and go
postganglionic sympathetic axons that come from superior cervical ganglion in the neck.
enter middle cranial fossa via foramen lacerum and join up immediately with the internal carotid that passes into the cranium via carotid canal immediately adjacent to lacerum
51
what does the deep petrosal nerve become
nerve of pterygoid canal
52
what happens within the pterygopalatine ganglion within the fossa
preganglionic parasympathetic fibers synapse with postganglionic fibers in pterygopalatine ganglion while postganglionic sympathetic fibers pass directly through with both innervating nasal glands and lacrimal gland
53
old pathway to lacrimal gland from pterygopalatine ganglion
maxillary (CN V V2) --> zygomatic branch of maxillary --> lacrimal nerve (branch of CN V V1) --> lacrimal gland
54
new pathway to lacrimal gland from pterygopalatine ganglion
direct innervation to lacrimal gland via nerve plaxus from pterygopalatine ganglion
55
what fibers are CN VIII (vestibulocochlear)
sensory only.
SSA
56
where does CN VIII enter
enters posterior cranial fossa (along with CN VII) via internal acoustic (auditory) meatus to medulla of hindbrain
57
how many sensory ganglia does CN VIII have
2 - each associated with balance and hearing
57
what are the 2 divisions of CN VIII
vestibular (balance) and cochlear (hearing)
58
what nerve fibers are in CN IX (glossopharyngeal)
mixed nerve.
GSA
GVA
SVA
GVE
SVE
59
where are CN IX nuclei located and where does it exit/enter
nuclei located within medulla.
exits/enters posterior cranial fossa via jugular foramen.
60
CN IX sensory innervation
GSA: touch to posterior 1/3rd of tongue, tympanic cavity, auditory tube (Eustachian or pharyngotympanic tube), oropharynx (back of oral cavity/mouth).
SVA: taste posterior 1/3rd of tongue.
GVA: chemoreceptors and baroreceptors in carotid aa.
61
CN IX motor innervation
SVE: skeletal muscle innervation to muscles of pharynx (aid in swallowing).
GVE: autonomic innervation to parotid gland via otic ganglion
62
what is the tympanic nerve a major branch of and what does it innervate
major branch of CN IX.
innervates tympanic plexus.
63
what does the lesser petrosal nerve innervate from
innervates from tympanic plexus and carries preganglionic parasympathetic the final way to the otic ganglion where it synapses with postganglionic parasympathetic fibers
64
where is the otic ganglion located
outside the skull and adjacent to foramen ovale
65
what do the postganglionic parasympathetic fibers from the otic ganglion 'hop' on to
outside of the auriculotemporal nerve and travel to innervate parotid gland nearby
66
what is the auriculotemporal nerve
sensory branch of CN V V3 as it conveys information from sensory receptors in the skin proximal to parotid gland to CNS
67
where are the parotid located
immediately anterior to external ear
68
what nerve fibers make up CN X (vagus)
mixed nerve.
GSA
GVA
SVA
GVE
SVE
69
where are CN X nuclei located and where do they exit/enter
within medulla.
exits/enters posterior cranial fossa via jugular foramen
70
where does CN X run
inferiorly within the carotid sheath - between internal carotid/common carotid aa. and internal jugular v. to supply neck, thorax, and abdominal structures (most extensive distribution of all CNs
71
CN X sensory innervation
GSA:
- external auditory ear canal/small portion of ear lobe
- middle ear
- larynx/laryngopharynx
- dura mater in posterior cranial fossa
SVA:
- taste from pharynx and epiglottis
GVA:
- aortic body/arch and esophagus
- heart
- lungs
- abdominal organs and viscera
72
CN X motor innervation
SVE:
- skeletal muscles of the soft palate, larynx/pharynx, and one muscle of the tongue
GVE:
- smooth muscle innervation to pharynx/larynx, thorax, and abdominal organs/viscera
73
what nerve fibers are CN XI (spinal accessory)
motor only
SVE - possibly originates from 6th branchial arch for cranial root.
GSE - spinal root
74
where are CN XI nuclei located
within medulla
75
where does the CN XI cranial root exit
exits skull along with spinal root via jugular foramen and travels with CN X
76
what does the cranial root of CN XI innervate
skeletal muscles of larynx
77
where does the spinal root of CN XI enter/exit
enters cranium via foramen magnum into posterior cranial fossa and exits via jugular foramen along with cranial root
78
what does the spinal root CN XI inntervate
2 superficial neck muscles:
- sternocleidomastoid
- trapezius
79
how is the spinal root CN X clinically assessed
instructing patient to shrug shoulders to asses trapezius muscle (while placing your hands on their shoulders to evaluate for resistance) or having patient turn head in each direction (left and right) to assess sternocleidomastoid muscle (while placing your hands on each side of face to evaluate for difference in resistance)
80
what nerve fibers is CN XII (hypoglossal)
motor only.
GSE
81
what does CN XII innervate
majority of tongue muscles
82
where are the CN XII nuclei located and where do they exit
in medulla.
exits posterior cranial fossa via hypoglossal canal (immediately superior to occipital condyles and foramen magnum)
83
how is CN XII clinically assessed
ask patient to stick out tongue.
tongue will deviate to weakened side if there is a CN XII palsy
84
what is the CNS contained within
dorsal body cavity with the brain in the cranial cavity and spinal cord in the spinal cavity
85
what do the brain vesicles form from
cranial end of the developing neural tube
86
what are the initial brain vesicles that form
primary brain vesicles, followed by development of secondary brain vesicles from the primary
87
what do the primary brain vesicles develop to form
forebrain (proencephalon).
midbrain (mesencephalon).
hindbrain (rhombencephalon)
88
what do the secondary brain vesicles develop to form
subdivisions of forebrain and hindbrain.
forebrain:
- cerebrum (telencephalon)
- thalamus, hypothalamus, epithalamus (diencephalon).
hindbrain:
- pons and cerebellum (metencephalon).
- medulla oblongata (myelencephalon)
89
what does gray matter consist of
soma and dendrites of neurons
90
where is gray matter located in the cerebrum
within the superficial cortex.
in isolated areas deep in the cerebrum as cerebral nuclei or basal nuclei
91
where is white matter located in the cerebrum
deep to the cortex
92
how do the positions of gray and white matter shift while moving from the cerebrum and midbrain into the hindbrain
ends up with gray matter being internal to the white matter in the lower portions of the brainstem (medulla oblongata) and into the spinal cord
93
what are tracts
white matter within CNS form bundles of fibers
94
how many layers do meninges have
3 layered connective tissue membrane
95
function of meninges
encapsulate and protect CNS and the vasculature that supplies CNS
96
where is CSF found
subarachnoid space - assists in circulation while moving excess CSF into dural sinuses =
97
what are the 3 layers of meninges
pia mater: inner layer. thinnest. tightly adhered to CNS.
arachnoid: middle layer. contains subarachnoid space.
dura mater: outer layer. thickest. toughest. contains outer periosteal layer and inner meningeal layer
98
what does the outer periosteal layer interface with
walls of the cranial and spinal cavities.
ex. skull and vertebra
99
what does the inner meningeal layer interface with
deep arachnoid
100
what are dural deflections (septa)
extensions of meningeal layer of the dura mater deep into cranium
101
falx cerebri
within longitudinal fissure.
separating right and left cerebral hemispheres.
102
falx cerebelli
within longitudinal fissure.
posteriorly separating right and left cerebellar hemispheres.
103
tentorium cerebelli
oriented perpendicular to falx cerebri and falx cerebelli.
separates cerebrum from cerebellum ('tent' over cerebellum)
104
diaphragma sellae
located adjacent to cavernous dural sinus.
smallest of the four
105
what is CSF secreted into the ventricles by
choroid plexus by an active, pressure-dependent process
106
where does CSF flow after passing through the fourth ventricle
into subarachnoid space within the meninges surrounding the brain and spinal cord or into the central canal of spinal cord
107
what are the 2 meninges that CSF flows into
2 lateral [Luschka] apertures or single median [Magendie] aperture
108
what is CSF composition closely reflective of
blood plasma
109
does CSF have a lower or higher protein concentration than blood plasma
much higher protein concentration within CSF due to proteins inability to pass through tight junctions between adjacent ependymal cells that comprise part of the choroid plexus
110
is CSF pressure normally greater or less than the dural sinus pressure
greater due to the constant secretion of CSF into ventricles, which creates a pressure gradient where the CSF passes through the arachnoid granulations and into the dural sinus
111
what does the inner layers of the cerebrum contain
sensory and motor tracts (white matter).
basal ganglia and associated structures (small patches of gray matter).
112
what is deep to the cerebrum and what does it contain
diencephalon, which contains areas of gray matter (ex. hypothalamus, thalamus, and epithalamus)
113
what do the telencephalon and diencephalon comprise
forebrain, or proencephalon
114
what are the lobes
frontal
parietal
temporal
occipital
115
what are the major fissures
longitudinal
lateral
calcarine
116
what are the major sulci
central
parieto-occipital
117
what are the major gyri
precentral
postcentral
temporal
118
what is the cerebral cortex in contact with
innermost layer of the meninges, the thin and delicate pia mater
119
what does the cerebral cortex cover
cerebral hemispheres
120
where is the cerebral cortex thinnest
bottom of a sulcus
121
where is the cerebral cortex
crest of a gyrus
122
how are the numerous tiny functional units that make up the cerebral cortex arranged
vertically through several layers of cortex and can have afferent and efferent neurons as well as interneurons
123
where can sensory/afferent information in a specific area of the cerebral cortex come from
other areas of cortex within same cerebral hemisphere.
corresponding cortex in opposing cerebral hemisphere.
from deep brain (ex. thalamus, basal nuclei, etc.)
124
where can motor/efferent information from a specific area of the cerebral cortex be sent to
other areas of cortex within same cerebral hemisphere.
corresponding cortex in opposing cerebral hemisphere.
lower parts of brain and spinal cord.
125
what type of neurons are pyramidal cells
multipolar
126
shape of cell body of pyramidal cells
pyramid shape
127
what are the main efferent output of cerebral cortex
pyramidal cells
128
where does the axon of pyramidal cells terminate
axon from basal surface can terminate deeper in cortex or leave cortex altogether
129
what happens to pyramidal cell bodies as they are going deeper into the cortex
increase in size as they are positioned deeper in cortex as these cells send signals over longer distances (projection cells)
130
what are stellate (granule) cells and what do they utilize
interneurons.
utilize GABA neurotransmitter
131
where are horizontal cells (of Cajal) and what do they do
in superficial-most portion of cortex.
interconnect pyramidal cells.
132
what are chandelier cells
inhibitory interneurons
133
what is the homotypical cortex
areas of cortex that have 6 distinct layers and remains similar in organization from fetus to adulthood
134
what are the 6 layers of the homotypical cortex from superficial to deep
Molecular layer (I)
External granular layer (II)
External pyramidal layer (III)
Internal granular layer (IV)
Internal pyramidal/ganglionic layer (V)
Multiform layer (VI)
135
what is the molecular layer (I) comprised of
mostly comprised of tangential fibers.
majority of input initially projects to this layer
136
what does the external granular layer (II) contain
cell bodies of stellate cells
137
what does the external pyramidal layer (III) contain
pyramidal cells, along with other interlinking cells
138
what does the internal granular layer (IV) contain
many stellate cell bodies
139
what does the internal pyramidal/ganglionic layer (V)
contains larger pyramid cell bodies
140
why is the granular type called the granular type
granular layers (II and IV) are well developed, while pyramidal layers (III and V) are not
141
what do layers II through V merge into
one highly granular layer.
so there are none-to-minimal pyramidal layers
142
what fibers project to the cells of the large granular layer
thalamocortical = thalamus to cerebral cortex - think sensory
143
examples of the granular type in postcentral gyrus and superior temporal gyrus
postcentral: primary somatosensory cortex
superior temporal: primary auditory cortex
144
why is the agranular type named agranular
poor development of granular layers (II and IV), while pyramidal layers (III and V) are very well developed
145
where is the agranular type found
precentral gyrus (primary motor cortex) and other areas of frontal lobe associated with motor function.
ex. frontal eye fields responsible for eye movements
146
what does the primary somatic sensory area (Brodmann 1, 2, 3) occupy
entire postcentral gyrus, which is mainly granular heterotypical cortex
147
primary somatic sensory area (Brodmann 1, 2, 3) main afferent input
sensation from thalamic axons
148
primary somatic sensory area (Brodmann 1, 2, 3) main efferent output
higher order sensory cortices
149
what is the secondary somatosensory area (Brodmann 40) adjacent to and what does it deal with
adjacent to primary somatosensory cortex.
deals with pain and tactile discrimination
150
location of somatic sensory association area (Brodmann 5, 7) and what does it do
located on superior parietal lobule.
many connections with other sensory areas of cortex.
integrates all manner of sensory information (the "where" pathway)
151
location of primary visual area (Brodmann's area 17 = V1 = Striate cortex)
along walls of posterior calcarine fissure of occipital lobe
152
what is the primary visual area comprised of
granular heterotypical cortex
153
where is afferent input of the primary visual area from
from LGN of thalamus via optic radiations through parietal lobe and temporal lobe
154
where does the primary visual area receive input from
temporal ipsilateral retina and nasal contralateral retina, so that each half of the visual field goes to the contralateral visual cortex
155
location of secondary visual area (Brodmann's areas 18 and 19; V2 and V3)
surrounds primary visual cortex
156
what does the secondary visual area (Brodmann's areas 18 and 19) receive
receives afferent fibers from primary visual cortex and pulvinar of the thalamus
157
what does the secondary visual area do with visual information
relates visual information with visual memory, allowing recognition
158
what does the pulvinar connection from the secondary visual area help do
control visual attention
159
where is the primary auditory area (Brodmann 41; inner region of auditory cortex) located
within superior temporal gyrus of the temporal lobe, which is a granular heterotypical cortex
160
where are afferent fibers of the primary auditory area from
from the medial geniculate nucleus of the thalamus
161
what are the cortical (Brodmann) sensory areas
Primary somatic sensory area
- Brodmann 1, 2, 3
Secondary somatosensory area
- Brodmann 40
Somatic sensory association area
- Brodmann 5, 7
Primary visual area
- Brodmann's area 17 = V1 = Striate cortex
Secondary visual area
- Brodmann's areas 18 and 19; V2 and V3
Primary auditory area
- Brodmann 41; inner region of auditory cortex
162
what are the cortical (Brodmann) motor areas
Primary motor area
- Brodmann 4
Secondary motor area
- Brodmann 6 and portions of 8, 44, 45; premotor area
Frontal eye fields
- parts o Brodmann 6, 8, 9
163
where is the primary motor area (Brodmann 4) located
within precentral gyrus and an agranular heterotypical cortex
164
what efferent and afferent tracts are there for primary motor area (Brodmann 4)
most efferent tracts to the brain and spinal cord.
afferent input arrives from many different parts of the brain to help control movement.
165
location of secondary motor area (premotor area; Brodmann 6 and portions of 8, 44, and 45)
over the anterior precentral gyrus and posterior portions of the superior, middle, and inferior frontal gyri.
6 times larger than primary motor cortex
166
what does the secondary motor area control
motor activity patterns based on experience, external cues and coarse postural movements by sending signals to the primary motor cortex
167
where does the secondary motor area receive afferent input from
all over to help coordinate movements
168
where are the frontal eye fields (parts of Brodmann 6, 8, 9) and what are they involved with
within frontal lobe.
involved with voluntary scanning eye movements
169
what does Wernicke-Broca locus control
understanding of language and our ability to express language
170
where is the sensory speech area of Wernicke (Brodmann 22)
superior temporal gyrus of left (or dominant hemisphere) temporal lobe
171
where does the sensory speech area of Wernicke receive afferent fibers from
primary visual and auditory cortices
172
what does the sensory speech area of Wernicke control
understanding of written and spoken language
173
where does the sensory speech area of Wernicke send efferent fibers
anteriorly to Broca's area of frontal lobe (Brodmann 44, 45)
174
results of injury to sensory speech area of Wernicke (Brodmann 22)
complete injury:
- receptive aphasia: inability to understand the spoken and written word; can understand what the word means.
injury to nearby angular gyrus: connection from visual cortex is severed
- alexia: inability to read
- agraphia: inability to write
175
location of motor speech area of Broca (Brodmann 44, 45)
within inferior frontal gyrus of left (or dominant) frontal lobe
176
what input does the motor speech area of Broca receive
input from many portions of the cerebral cortex
177
what does the motor speech area of Broca have efferent connections with
motor centers of cortex
178
what does broca's area bring about
muscular movements involved in speech, including control of larynx, mouth, tongue, soft palate, and respiratory muscles
179
injury to broca's area
injury:
- expressive aphasia: inability to produce speech; can still think in words and write words.
injury that destroys entire wernicke-broca locus:
- causes global aphasia: inability to understand spoken or written words, and inability to speak
180
when are hemispheres of the neonatal cerebrum identical
at birth
181
which hemisphere is dominant in 90% of people
left
182
left hemisphere dominant - handedness
dominant hemisphere of brain has more pyramidal neurons than non-dominant half.
decussate in medulla oblongata along their course, causing the opposite hand to be more dexterous of the 2
183
which hemisphere are perception of language and speech
dominant
184
what is the non-dominant hemisphere mainly involved in
spatial perception.
facial recognition.
understanding of music
185
what does cerebral white matter form
majority of deep cerebrum
186
what do association fibers connect
different parts of cerebral cortex within the same hemisphere
187
what are the 2 types of association fibers and what do they connect
short association fibers: connect areas of cerebral cortex from different gyri within same cerebral lobe.
long association fibers: connect areas of cerebral cortex from different lobes within same cerebral hemisphere.
188
what do commissural fibers connect
portions of the cerebral cortex in one hemisphere with its partner in the other hemisphere by crossing from one hemisphere to the other in one of 4 cerebral commissures
189
4 cerebral commissures
Corpus callosum:
- largest cerebral commissure.
- has rostrum (most anterior part), genu (knee or bend), trunk or body, and splenium (most posterior part).
Anterior commissure:
- small area on the edge between frontal lobe and thalamus.
- carries commissural fibers that connect olfactory tracts and limbic systems together.
Posterior commissure:
- at the edge between temporal lobe and thalamus.
Habenular commissure:
- superior to posterior commissure
190
what do projection fibers project to
elsewhere in the nervous system
191
where do projection fibers travel
in corona radiata and internal capsule
192
what are the basal nuclei (ganglia) and where are they
isolated centers of grey matter and neuronal soma deep within white matter of cerebrum.
Major voluntary motor control center.
193
components of basal nuclei (ganglia)
corpus striatum - caudate and lentiform nuclei.
internal capsule.
- caudate nucleus
- lentiform nucleus: putamen and globus palladus.
amygdala
hippocampus
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what is the corpus striatum comprised up of
caudate and lentiform nuclei.
separated by the internal capsule
195
what is the internal capsule
very large band of white matter that contains major projection fibers of the corticospinal tract and separates the caudate and lentiform nuclei.
also separates globus pallidus from inner thalamus
196
shape and location of caudate nucleus
C-shaped grey matter nucleus.
its head begins anteriorly to the lentiform nucleus, then stretches superiorly and posteriorly, over the thalamus, as the caudate nucleus body.
nucleus then descends and runs anteriorly inferior to the lentiform nucleus as the tail of the caudate nucleus.
197
shape and components of the lentiform nucleus
oval/"lens shaped."
2 parts:
1. Putamen: lateral part.
- dark gray collection of neuronal soma and axons.
- adjacent to inferior portion of caudate nucleus head.
2. Globus palladus (palladium): medial part.
- grey matter (lighter than putamen) due to presence of some myelinated fibers.
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what do the globus palladus and putamen have between them
thin layer of white matter
199
why the name "corpus striatum" for the caudate nucleus and lentiform nucleus
white matter barrier is spanned by grey matter fibers that give the area a striped appearance
200
shape and location of the amygdala
almond-shaped grey-matter nucleus deep in the anterior temporal lobe.
emerges from the anterior end of the tail of the caudate nucleus, but is functionally more associated with the limbic system than the corpus striatum.
201
what is the amygdala involved in
visceral changes to emotions, pain, and fear response
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location of the hippocampus
extension of cerebral cortex of medial temporal lobe.
contains neuronal soma and grey matter axons.
extends from anterior portion of deep temporal lobe more posteriorly, when it ends, sending its axons to the fornix.
203
what system is the hippocampus involved in
limbic
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what is the hippocampus functionally involved in
transforming short-term to long-term memory
