nervous system chapter 13 Flashcards
55 y/o male to A&E with weakness in right arm and leg. Reduced tactile sensation on his right arm and leg.
Which side of the brain affected and why?
- left side of brain
- contralateral hemisphere supplies motor sensation
- due to decussation
2 most common causes that would lead to weakness in both legs and reduced tactile sensation in both legs
- thromboembolic stroke
2. haemorrhagic stroke
nerve roots when testing biceps
C5, C6
nerve roots when testing ankle jerk
S1
nerve roots when testing patellar reflex
L3, L4
Where is CSF produced and reabsorbed?
- choroid plexus via ultrafiltration in ventricles
- travels via intraventricular foramen on Monroe from lateral to third ventricles
- through cerebral aqueduct into fourth ventricle
- via foramina of Magendie and Luschka into subarachnoid space
- reabsorbed via arachnoid granulations in the superior saggital sinus
Long term alcohol abuse can result in:
- degeneration of neutrons in cerebellar cortex via nutritional deficiency
describe break down of alcohol
- alcohol oxidised to acetaldehyde via alcohol dehydrogenase
- acetaldehyde oxidised to acetate via aldehyde dehydrogenase
classic triad of cerebellar disease
- dysdiadochokinesia
- dysmetria (lack of coordination of movement)
- ataxia
outline mechanisms for repair when a peripheral nerve is damaged?
- Wallerian degeneration of distal axon begins
- macrophages, phagocytes and Schwann cells migrate and clear necrotic debris
- axonal sprouting then occurs at proximal stump
- grows until they enter distal stump
which part of the brain is commonly affected in Parkinsons?
- basal ganglia
functions of basal ganglia
- control of voluntary motor activity
- control of reflex muscular activity
- control of muscle tone
What three signs characterise Parkinsons disease?
- tremor at rest
- rigidity
- bradykinesia
some ocular signs that may be present with an expanding brain haematoma?
- papilloedema
- esotropia (Esotropia is a form of strabismus in which one or both eyes turns inward.)
- mydriasis (dilation of pupil of eye)
- ptosis
extradural haemorrhage
- between skull and periosteal dura
- due to meningeal artery rupture
subarachnoid haemorrhage
- between arachnoid and Pia mater
- contains CSF
subdural haemorrhage
- potential space between dura and arachnoid
- due to rupture of bridging veins