Anatomy 22 (Neuro 5) Flashcards
(46 cards)
What is the purpose of the limbic system?
Acts as an interface between the internal environment of the individual and the external environment
What are the 2 major functional roles of the limbic system?
Learning
Regulation and translation of our emotional state into appropriate behaviour
What brain structures does the limbic system include?
Cingulate gyrus
Hippocampal formation and parahippocampal gyrus
Anterior perforated substance
Septal nuclei
Uncus
Amygdala
(Thalamus, Hypothalamus, Epithalamus and Subthalamus)
What does the uncus play a role in?
Role in olfaction, emotions and memory
What are association fibres?
Axons interconnecting different areas of the cerebral cortex of one hemisphere
What is the largest bundle of association fibres?
Superior longitudinal fasciculus
What does the stria terminalis connect?
Amygdala with the septum and hypothalamus
What can lesions in the limbic system result in?
- Anterograde amnesia
- Generation of emotions and emotional responses in the absence of external stimulation
- Production of inappropriate emotional responses to particular stimuli
- Inability to detect the emotional state of others
- Inability to regulate our own emotional responses
What is hydrocephalus?
Blockage of CSF flow in ventricles or subarachnoid space leads to rise in fluid pressure causing the ventricles to swell
How can pressure due to hydrocephalus be relieved?
By insertion of a shunt connecting the ventricular system to the peritoneum or jugular vein
What are some signs/symptoms of hydrocephalus?
Raised intracranial pressure
Headache
Unsteadiness
Mental impairment
What is the claustrum part of?
Basal ganglia
What is the claustrum derived from?
Telencephalon
What do the cells in the claustrum respond to?
Visual, auditory and sensory stimuli
What is the external capsule?
White matter separating the claustrum from the putamen
What is the internal capsule?
Convergence and concentration of white matter projection fibres which carries all the motor and sensory fibres from and to the cortex
What is Parkinsons disease?
Degeneration of dopaminergic neurones of the substantia nigra leading to depletion of striatal dopamine levels
What treatment can help minimise the symptoms of Parkinsons disease for years?
Levodopa
What are some signs/symptoms of Parkinsons disease?
Cog-wheel rigidity
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 the inheritance linkage of Huntington’s chorea?
Autosomal dominant
What are some signs/symptoms of Huntington’s chorea?
Chorea (‘dance-like’, overshooting, writhing, involuntary movements)
Personality change
Depression and progressive dementia due to degeneration of the corpus striatum and cerebral cortex
What is a lacunar stroke?
Occlusion of a deep perforating artery
What are some strong risk factors of lacunar stroke?
Hypertension
Smoking
Diabetes
Where do the resultant lesions of lacunar stroke occur in?
Deep nuclei
Pons
Internal capsule
