Olfactory & limbic system, basal ganglia Flashcards
what are the two major functional roles of limbic system?
- learning
2. regulation and translation of emotions into appropriate behaviour
what does the limbic system consist of and how are they all connected? CHAAP-NU
- cingulate gyrus
- hippocampal formation
- anterior perforated substance
- amygdala
- septal nucleui
- uncus
- they are all connected the via the papez circuit
what do you find above and below the corpus callosum?
above - cingulate gyrus and cingulum
below - fornix
which is the largest bundle of association fibres?
superior longitudinal fascicules
what does a lesion in limbic system result in?
1a. generation of emotions and emotional responses in the absence of an external stimuli
1b. production of inappropriate emotional responses to a certain stimuli
1c. inability to detect the emotional state of others and inability to regulate our own responses
2. anterograde amnesia
what is hydrocephalus?
- blockage of CSF flow in ventricles (e.g. tumours) or subarachnoid space (e.g. adhesions following meningitis or trauma) leads to rise in fluid pressure causing the ventricles to swell
what are the symptoms and signs of raised intracranial pressure?
headache, unsteadiness and mental impairment
how can the pressure be relieved in hydrocephalus?
relieved by insertion of a shunt connection the ventricular system to the jugular vein or peritoneum
what forms the lentiform nucleus and striatum?
lentiform nucleus - putamen (outer) + globus pallidus (inner)
striatum - putamen (outer) + caudate nucleus (above)
outline the old papez circuit pathway and what is included in the new one?
old papez circuit - parahippocampus gryus -> hippocampus -> fimbria-fornix-> mammilary body- MTT -> anterior nucleus -> cingulate gyrus-cingulum -> parahippocampus- entorhinal cortex -> hippocampus
new - amygdala + hypothalamus
outline its location in the brain
- caudate nucleus
- stria terminalis
- caudate nucleus - follows the curve of lateral ventricle to inform horn and consists of caudate head-body-tail
- stria terminalis - follows the caudate nucleus and connects the amygdala to the septum and hypothalamus
what is the location and function of caudate tail?
- location: at the tip of (above) inferior horn of lateral ventricle
- function: connects to the amygdala for fear
what is the location and function of hippocampus? and what is pes hippocampi?
- location: lies medially in the inferior horn of lateral ventricle (5cm)
- function: long term memory + emotion
- pes means paw like and the end of the hippocampus looks like a claw thus giving the name pes hippocampi
what is the pathology of PD, symptoms (PBL-CSF) and treatment?
- Pathology: degeneration of dopaminergic neurons of substantia nigra with depletion of striatal dopamine
- cause: unknown, some genetic
- symptoms: cog-wheel rigidity (muscular 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 cause and symptom of HD? (PCDD)
- cause: autosomal dominant inheritance, shrunken head of caudate nucleus and eventually whole brain atrophy
- symptoms: chorea (overshooting, unintentional movements), personality change, depression and progressive dementia due to degeneration of corpus striatum and cerebral cortex
