Norden - Cerebral Hemispheres Flashcards
The smallest basic functional unit of neocortex. Between 40 and 50 micrometers diameter
Mini columns
Play a major role in separating mini and macro columns in cortex. Play major role in original definition of mini columns during development
Vellate astrocytes
Thought to be due to disorders of the columns in the cortex. Associated w/ an increased number of mini columns and increased subcortical white matter
Autism spectrum disorder
The inability to carry out a voluntary movement despite having all motor, sensory, and language functions intact.
Seen in degenerative disorders like Alzheimer’s where you get massive loss of neurons, particularly in cortical association cortex.
Apraxia
What in the brain typically inhibits infantile reflexes when functioning normally?
The prefrontal cortex
This is a cortical sign when you see these reflexes.
What are some cortical side
Contralateral neglect (non dominant hemisphere)
Aphasia (dominant hemisphere)
Agnosia
Apraxia
Frontal release signs (infantile reflexes)
Eye deviation (w/o brainstem localization)
Memory loss ( if prefrontal cortex or hippocampus is involved)
Names for the deep white matter of the hemispheres lying immediately beneath the cortex
Medullary center
Or
Centrum semiovale
This is an association pathway, that is a part of the superior longitudinal fasciuculus and in the dominant hemispheres connects the language areas with each other
Arcuate fasciculus
Lesions of the arcuate fasciculus will cause?
Conduction aphasia
People who can speak and hear language, but when they try to answer a question they will give inappropriate responses..
Conduction aphasia.
Due to lesion in the arcuate fasciculus in the dominant hemisphere.
How can the integrity of the arcuate fasciculus fibers be tested ?
By asking a patient to repeat a phrase. If they cannot, may have lesion.
Cell bodies of origin of the cingulum association pathways.
Cingulate gyrus.
Posterior cingulate is involved in what?
Default mode network (internal cognition, thought, dialogue)
A major pathway allowing the emotional content of our experiences to be integrated w/ our memories/cognition
Cingulum tract.
The genu of the internal capsule carries
Corticobulbar axons
The posterior limb of the internal capsule carries
Descending axons of the corticospinal tract and ascending (from VPL and VPM) axons of the somatosensory systems.
The sublentricular portion of the posterior capsule carries?
Auditory radiations
The retrolentricular portion of the posterior limb carries?
Visual radiations
What part of the internal capsule do limbic projections go through ?
The anterior limb.
The anterior internal capsule gets its lood from ?
Penetrating branches of the anterior cerebral artery
The genu and posterior limb of the internal capsule gets its blood from ?
Penetrating branches of the middle cerebral arteries (lenticulostriate arteries)
The posterior limb of the internal capsule is a major site for ?
Ischemic and hemorrhagic strokes.
In the hemispheres, always look for asymmetries or abnormalities in what on CT/ MRI?
Ventricular system
A group of subcortical nuclei lying deep w/in the cerebral hemispheres.
Derived from prosencephalon in development
Divided into dorsal striatal structures and ventral striatal structures
Basal ganglia
The dorsal striatal structures (subdivision of basal ganglia) are primarily involved with ?
Motor functions
medial to the putamen and “connected” to it;
divided into lateral (external) and medial (internal) segments; separated from the
Cerebral Hemispheres
thalamus by the fibers of the posterior limb of the internal capsule
Globus pallidus
Te caudate, putamen, and globus pallidus are collectively referred to as the
Corpus striatum
The putamen and globus pallidus are not related embryologically.
They are collectively referred to as ?
The lentiform
The caudate and putamen are related embryologically. They are collectively called the
Neostriatum
Subcortical limbic structure.
Plays extremely important role in innate and leaned fear and in emotional memory
Amygdala
