Deep Structures in the Hemisphere Flashcards
What is the extreme capsule?
Long association fiber pathway of white matter in the brain that provides bidirectional communication between such areas as the claustrum and the insular cortex, and the inferior frontal gyrus and the middle-posterior portion of the superior temporal gyrus
What is the claustrum?
Forms part of the basal ganglia being a subcortical nucleus dervived from the telencephalon
It receives from and projects to the cerebral cortes in a topographically organised matter and is known to have cells within it which respond to visual, auditory and sensory stimuli
What is the external capsule?
White matter separating the the claustrum from the putamen
What is the lentiform nucleus made up of?
The putamen (laterally) and the globus pallidus (medially)
What is the lateral medullary lamina?
White matter between the putamen and the lateral segment of the globus pallidus
What is the globus pallidus?
A grey matter component of the basal ganglia, it is triangular-shaped and medial to the putamen
What is the medial medullary lamina?
White matter between the lateral and medial segments of the globus pallidus
What is the internal capsule?
A V-shaped structure, it is a concentration of white matter projection fibres which carry all the motor and sensory fibres to and from the cerebral cortex
It carries information past the basal ganglia, separating the caudate nucleus and the thalamus from the putamen and the globus pallidus.
What is the corona radiata?
White matter fibres radiating from the internal capsule, deep to the lentiform nucleus
What are the components of the basal ganglia?
The basal ganglia consist of five pairs of nuclei: caudate nucleus, putamen, globus pallidus, subthalamic nucleus, and substantia nigra.
What is the forceps major?
The posterior curve of the corpus callosum fibres into the parietal and occipital lobes forming about 2/3rds of a circle with the opposite side fibres
What is the forceps minor?
Anterior curve of the corpus callosum fibres into the frontal lobe forming about 2/3rds of a circle with the fibres of the opposite side
What is Parkinson’s Disease?
Degeneration of dopaminergic neurones of the pars compacta of the substantia nigra with depletion of striatal dopamine levels. Treatment with levodopa can minimise symptoms for years
Symptoms:
Cog-wheel reigidity
Pill rolling tremor at rest (thumb and forefinger)
Shuffling, festinant gait (difficulty starting and stopping)
Bradykinesia (slowness of movements)
Loss of facial expressions
What is Parkinson’s Disease?
Degeneration of dopaminergic neurones of the pars compacta of the substantia nigra with depletion of striatal dopamine levels. Treatment with levodopa can minimise symptoms for years
Symptoms:
Cog-wheel reigidity
Pill rolling tremor at rest (thumb and forefinger)
Shuffling, festinant gait (difficulty starting and stopping)
Bradykinesia (slowness of movements)
Loss of facial expressions
What is Huntington’s chorea?
Autosomal dominant inheritance
Symptoms:
chorea (overshooting, unintentional movements)
Personality change
Depression and progressive dementia due to degenration of the corpus striatum and cerebral cortex
