The Telencephalon Flashcards
what do the telencephalon outgrowths arise form?
the developing HT
what does each telencephalon outgrowth form?
a cerebral hemisphere (cerebrum)
what dot he cerebral hemispheres consist of?
the pallium
the subpallial layer
what is the oter layer of the cerrebrum called?
the pallium
what is the inner layer of the cerebrum called?
the subpallium / subpallial layer
what layer of the cerebrum includes the cortex/future cortex
the pallium
what groups does the subpallium form?
deep cell groups
what are the major deep cell groups the the subpallium forms?
the striatum
the palliidum
in textbooks, what are the pallidum and basal ganglia collectively known as>?
the bsal ganglia
telencephalic outgrowths arise from where in the Ht>?
the alar plate of the ropstral HT segment
iwhat are the four parts of the palliyum
medial pallium
dorsal pallium
lateral pallium
ventral pallium
in mammals, most of the cerebreal cortex is derived from twhat part of the pallium?
the dorsal pallium
at is the cerebral cortex also known as>?
the neocortex
what does the dorsal pallium mainly contain?
the neocortex
what areas derive from the ventral pallium
olfactory system areas (the allocortex)
what is another name for the olfactory parts of the cortex?
the allocortex
what [art of the pallium do olfactory areas / allocortex arise from?
the ventral pallium
the lateral pallium lies between what two cortex parts?
between the neocortex and allocortex
what small neocortical area does the lateral pallium form?
the insual
what part of the pallium is the insula in?
the lateral pallium
what is the insula devoted to?
taste + visceral sensations
what does the medial pallium give rise to?
the hippocampus
what part of the pallium does the hippocmpaus arise from?
the medial pallium
what increases the massively expanded surface area of the human neocortex?
folding
what are raised areas in the cortex called?
gyri
what are grooves in the cortex called?
sulci
what separates the medial pallium (hippocamous) from the dorsal pallium (neocortex)
the corpus callosum
what is the cerebrum, divided into?
lobes
what are the lobes of the cerebrum named for?
the overlying cranial bones
what are the lobes of the cerebrum called>
frontal lobe
occipital lobe
temproal lobe
parietal lobe
what separates the frontal and parietal lobes?
the central sulcus
what separates the temporal lobe from the frontal + parietal lobes?
the lateral fissure
the neocortex has well defined sensory areas for:
touch
vsision
hearing’
taste
where is the vuisual cortex?
the occipital pole of the cortex
where is the auditory cortex?
the tem[poral lobe
where is the touch/somatosensory cortexc?
located rostrally near the frointal pole
the neocortex has no sensry area for:
olfaction
where is all olfactory info projected to?
ventral cortical areas
what are the ventral cortical areas that olfactory info is projected to?
the olfactory bulb
the olfactory tubercle
the piriform cortex
what is in front of the somatosensory cortex?
the primary motor cortex
what is the primary motor cortex devoted tro?
voluntary motor control of the opp side of the body
the motor cortex sends major pathways to where?
BS and SC
the motor cortex sends what major patheway to the bS?
the corticobulbar tract
the motor cortex sends what major patheway to the SC?
corticospinal tract
the motor cortex sends major pathwaysd to the bS and SC to do what>
initiate movement
abbreviation for primary somatosensory area:
s1
abbreviation for primary motory area:
m1
S1 and M1 are separated by what?
the central sulcus
abbreviation for primary auditory area:
a1
a1 and s1 are separated by what?
deep lateral fissure
abbreviation for primary visual area:
v1
v1 us almost entirely located on:
the medial side of the occiptial lovbe
in diagrams, wht may the taste cortical areas notbe seen?
becasue it is hidden in lateral fissure
at histological level, neocortex has what welldefined levels?
layers 1 - 6
what are primary sensory areas characterised by?
dense granule cell layers (2+4)
hat are the granule cell layers?
2 and 4
what is the primary motor cortex characterized by?
prominent pyramidal cell layer (layer 5)
virtual absense of granule ce;ll layer (layer 4)
t is the pyramiudal cell llayer?
layer 5
why are many layer 5 pyramidal cells lrge?
because theysend axons over great distances to reach MN in the SC
in S1, layer 4 is:
prominent
In M1, layer 4 is:
virtually absnet
what is the hippocampus involvewd in?
memory systems
what does the hippocampsu consist of?
the dentate gyrus
the 3 CA regions
the subiculum
the entorhinal cortex
hat is the hippocmnpaus responsible for?
short-term memory regiistration
where is the entoriuhinal cortex located?
in the parahippocampal gyrus?
what tool is the entorhinal cortex similar to?
a GPS that contains a precise 2D grid map of surroundings
t does the entorhinal cortex help do?
link memories of events to where they occured
the enotorhinal cortex send splace info to the hippocampus as a:
chain of connnections from the dentate gyrus, the CA3 region. and finally the CA1 region
the chain of connectins from the enotorhinal cortex to the hippocampus pass through where?
the dentate gyrus
, the CA3 region.
and finally the CA1 region
what does the CA1 region do?
sends info to the subiculum
what is the subiculum?
the output center of the hppocmapus
where does the subiculum project to?
the septum
the hT
the subiculum projects to the septum and and Ht via a large fiber bindle called the:
the fornix
at are the largest specialized neuron groups under the pallium coverings?
the striatum
the pallidym
what do the pallidum and striatum play an important role in?
movement contorl
at are the smaller subpallial groups?
the amygdala
the septum
the preoptic area
the amygdala the septum and the preoptic area are concerned with what?
emotional expression
behavioural patterbs
why is it best to avoid the term basal ganglia?
because people define it as include differnet structures sucg as the amygdala and deep forebrain structures. insteado of only the striatum and globus pallidus
t are the 2 parts of the striautm?
the caudate nucleus
the putamen
what is the medial side of the putamen?
the pallidum
what is the pallidum mainly represented by?>
the globus pallidus
what brain strucutes form the brains powerful m otor control system
the striatum and pallidum
t do the striatum and pallidum enable the brain to do?
choose froma library og inherited stereotyped behaviours according to needs at thge moment in time
the striatum receives whar input?
major motor cortex input
after receiving major motor cortex input, where does the striatum project to?
the globud pallidus
where does the globus pallidus project dto?
the ventrolateral nucleus of the TH
where does the ventrolateral nucleus of the TH project to?
the motor cortex
what is the motor control loop in the brain?
motor cortex -> striatum -> globus pallidus -> ventrolateral nucleus of TH -> back to motor cortex
the striatum forms an important dopaminergic pathway that arises from where?
the substantia nigra
what are the striatum and substabtia nigra connected by?
an important dopaminergic pathway
what does damage to the dopaminergic pathway that arises form the substantia nigra and connects the striatum cayse?
parkinsons disease
where does the acumbens nucleus locateD in relation to caudat eand putamen?
ventral to rostral parts of caudate and putamen
what is ventral to rostral parts of caudate and putamen?
the acumbens nculeus
the accumbens nucleus receives dopaminergic projections from where?
BS
the accumbens nucleus receives what from the BS?
dopaminegic projections
wheret do dopaminergic projections from the BS that are recieved in the accumebns nucleus come from?
the ventral tegmental area
where is the ventral tegmental aras in relation to the substantia nigra>
mediual to substantia nigra
what do the dopaminergic projections to the accumebsn nucleus form the basis of?
the brains internal rewards system
what is another name for the primary olfactory cortex?
the piriform cortex
where does the substantia lie in rleation to the piriform cortex?
deep to piriform cortex
where in what lobe does the amygdala located?
medial side of temporal lobe
where is the amygdala in relation to the hippocmapus
just rostral to hippocampus
what are the two main groups of subnuclei in the amygdala?
medial group
lateal group
what is the medial group of the amygdala interconnected with?
the olfactory system
what is the lateral group of the amygdala iconnect wityh? in particular what?
emotional response circuits
particularly fear
the lateral amgydala group reacts to:
responses that signal danger
how does the lateral amgydala group react to responses that signal dangeR?
reacts by activating autonomic and endocrine centres (fight or flight mechanisms)
what are most of the reponse circuits with lateral amgdala group also interconnected witg>?
the hT
what do fear and stress generate through the amygdala?
powerful, unconsiuous emotional memories
unconcious fears generated by the amygdala are difficult to:
suppress or erase
hieracrchial behaviour control is a major role of what?
the amygdala
social hierarehcies are fundamental to aniamsl that:
belong in large groups hwere dominance behaviours maintain effectivenss of group strucutre
what complex, misinterpreted behaviour has a relationship with the amygdala?
aggression
what are the stongest aggressive behaviour forms in the same species related to?
attempts to establish a place in a hierarhcy
in textbooks, the section with the amygdala and related structures is called:
the limbic system
what is the logic behind the old term limbic system?
that all structures involved in emotions or primitive behaviours are lumped under the smae title
why should the term limbic system be avoided?
because it can be defined in many confusing wyas
what is deep to the cerebral cortex?
a thick WM layer
in connectional terms, axons iun the cerebral WM have what 3 main types?
association fibers
commisural fibers
projetion fibers
what are association fibers?
fibers that run from the cortex to another cortex area in the same hemisphere
(can join adjacent or long distance nuclei/strucutres, even in between diff lobes)
what are commissural fibers?
fibers that join cortical aras of one hemisphere to the equivalent areas in the other hemisphere
what are projection fibers?
fibers that travel downwards from the cortex to the striatum, pallidum, diecncephalon, MB, HB, SC or upwards ti the TH or cprtex
how many commissures are there in the forebrain?
4
what is the main commissure in the forebrian?
the corpus callosum
what does the corpus callosum connect?
neocortical aras of both sides
what are the 4 commissures in the forebrain?
corpus callosum
hippocampal commissure
anterior commissure
posterior commissure
what is another name for the hippocampal commissure?
the fornix commissure
what does the hippocampal/fornix commissure connect?
both hippocampal regions
what does the anterior commissure connect?
areas of temproal lobes (including some olfactory areas)
where is the posterior commissure?
in the pretectal areas of diencephalon (adjacent to MB)
What is the corpuss callosum situated under?
the cingulate gyrus
What is the corpuss callosum situated uabove?
the septum and the lateral ventricle
what is the rostral end of the corpus callosum called?
the genu
what does the ventral tip of the genu of the corpus callosum form?
the rostrum of the corpus callosum
what is the centrral part of the corpus callosum called?
the body of the corpus callosum
what is the thickened caudal end of the corpus callosum called?
the splenium
mostly, fibers crossing the corpus callosum connect ___ cortex parts
symmetrical
fibers crossing the genu of the corpus callosum reach where? in what shape?
the frontal lobe tip in U shape
fibers crossing the genu of the corpus callosum reach the frontal lobe tip in U shape called what?
the forceps minor
fibers crossing the splenium of the corpus callosum reach where? in what shape?
the tip of occipital lobe in a larger u shape
fibers crossing the splenium of the corpus callosum reach the tip of occipital lobe in a larger u shape called the?
forceps major
where is the hippocampal commissure in relation to the corpus callosum?
ventral
the anterior commissure is at what end of the diencephalon?
rostral end
the anterior commissure is where in relation to the anterior fornix columns
in front of
what commissure is a useful landmark in forebrain sections at rostral diencephalon end?
the anterior commissure
the anterior commissure lies at what rostral diencephalon level?
at the level where the interventricular foramen connects lateral and 3rd ventricles
the preoptic areas is ___ to the anterior commissure
ventral
what is the most ventral part of the subpallium
the anterior commissure
what is caudal to the preoptic area?
rostral end of HT
what is the anterior commissure a good marker for?
rostral end of hippocampus and amygdala
what commissure is in the caudal pretectal areas?
the posterior commissure
what does the posterior commissure link?
pretectal nuclei involved in eye reflexes
gene expression proves that the posterior commissure lies in the:
caudal diencephalon
modern studies estimate there are how many antatomically and functionally distinct areas in the human neocortex?
180
what was the most influential attempt to define the major cortical areas?
The Brodmann areas of the cortex
what is Brodmann area 4?
M1
where is Brodmann area 4?
precentral gyrus
what are Brodmann areas 9 +10?
prefrontal cortex
Brodmann areas 9 +10 are ___ to M1
rostral
what are Brodmann areas 1, 2 +3
s1
where are Brodmann areas 1,2+3
post-central gyrus
what is Brodmann area 41
a1
where is Brodmann area 41?
temporal gyrus (mainly inside lateral fissure)
what is Brodmann area 17?
v1
where is Brodmann area 17?
medial surface of occipital lobe
what are Brodmann area 44+45?
Broca’s area (motor speech area)
what is broca’s area also known as?
motor speech area
where are Brodmann area 44+45
parts of inferior frontal gyrus (immediately rostral to inferior part of the precentral gyrus in the dominant hemisphere)
what are Brodmann area 39+40?
Wernicke’s area (speech comprehension area)
where are Bordmann areas 39+40?
upper surface of superior temporal gyrus caudal to A1 in the dominant hemisphere
(most of Wernicke’s area -> in lateral fissure)
what is wernickes area also known as?
speech comprehension area
