Telencephalon Anatomy Flashcards
What are the adult vesicles (parts of CNS) that arise from the telencephalon?
Cerebral hemispheres
Certebral cortex
Subcortical white matter
Basal ganglia
Basal forebrain nuclei
3 types of white matter tracts
1) Association tracts:
- link cortical regions within the SAME cerebral hemisphere
- ex: right hemisphere parietal lobe -> right hemisphere occipital lobe
2) commissural tracts:
- link corresponding cortical regions between SEPARATE hemispheres
- ex: right hemisphere -> left hemisphere
3) Projection tracts:
- link cortical and subcortical regions from around the CNS
- Ex: cortex -> outside cerebral hemispheres
Superior longitudinal fasciculus
A type of association tract
Connects the frontal and occipital lobes from the same hemisphere
Arcuate fasciculus
A type of association tract
Connects the frontal and temporal lobes of the same hemisphere
important for language function
Inferior longitudinal fasciculus
A type of association tract
Connects the occipital and temporal lobes in the same hemisphere
important for visual recognition
Uncinate fasciculus
A type of association tract
Connects anterior and inferior parts of the frontal lobe with the temporal gyri of the same hemisphere
important for behavior regulation
Cingulum
A type of association tract
Connects frontal and parietal lobes with he parahippocampal and adjacent temporal gyri of the same hemisphere
- important for emotion regulation*
Corpus callousum
A type of commissural tract
Connects both hemispheres of the brain and allows intercommunication
- also gets help from the anterior/posterior commissures*
Hippocampus commissure (fornix)
A type of commissural tract
Aids in helping the hippocampus with communicating between the hypothalamus and the hemispheres of the cerebral cortex
Also aids in right-> left hippocampus communication (and vise versa)
Split-brain
A Clinical condition that occurs when the corpus callous is split in some way
The brain still functions normally but the hemispheres work autonomously between each other
Because of this, sight, motor and speech dont work in tandom
- example: patient sees an object out of their left eye but cant name anything they see
- example: patient cant see anything out of their right eye but can use their left hand
What hemisphere is language production found?
Left hemisphere
What hemisphere is visual and motor cortex found
Both sides but are crossed
ex: right motor and visual cortex functions the left eye and hand
Alexia without agraphia
A clinical condition that occurs when the splenium portion of the corpus callousum is damaged
Causes defects in understanding written material, but they can speak and write normally
this is caused because the visual processing center on the right cant communicate with the verbal processing and motor sections on the dominant left hemisphere
What hemisphere is verbal processing found in?
Left hemisphere is dominant
Corona radiata
A type of projection tract
Cerebral cortex communicates with subcortical regions
Condenses from the cerebral cortex into the internal capsule
What does the anterior limb of the internal capsule separate?
Caudate nucleus (medial) from the putamin and the Globus palatus
What does the posterior limb of the internal capsule separate?
Thalamus (medial) from the globus palltus and the putamin
What are the 3 broad subsections of the cerebral cortex?
1) Allocortex
- includes archicortex and Paleocortex
2) Mesocortex (Juxtallocortex)
3) Neocortex (Isocortex)
Allocortex contents
Has 3 histologically layers and 2 sub catagories
Archicortex
- hippocampus
- uncus of parahippocampus
- dentate gyrus
Paleocortex
- olfactory (piriform) cortex
is largest in primitive species, but less in humans
Mesocortex contents
Is 3-5 histologically layers
Contains:
- cingulate gyrus
- all of parahippocampus except uncus
- orbitofrontal cortex
- temporal pole
- anterior insula
Neocortex contents
Has 6 histologically layers
Makes up everything else in the cerebral cortex not in the mesocortex or allocortex
most prominent in humans and less in primitive species
Overview of general limbic structures in the limbic system
Major cortical areas:
- para-hippocampal gyrus
- cingulate gyrus
- prefrontal cortex
- temporal pole
Also includes the following
- amygdala
- septal nuclei
- hypothalamus
- hippocampus formation