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Flashcards in Forebrain Dz Deck (20):
1

what is the forebrain? what is it formed of?

area of brain rostral to the tentorium cerebelli (divides cerebellum and forebrain)
- formed of telencephalon (cerebrum) and thalamus (part of diencephalon)

2

Know where different regionsof the cortex lie

- olfactory bulbs and tracts
- forntal lobes
- parietal lobes
- temporal lobes
- occipital lobes q

3

Which cranial nerves do not exit the brainstem?

1 + 2
- all others exit the brainstem

4

Where do the olfactory bulbs and tracts lead to and what are they responsible for?

- perception of smell
- cell bodies in nasal epithelium
- cribiform plate
- limbic system
- cribiform lobe
- rhinencephalon

5

what is specieal about CN1 and 2?

not really nerves
- olfactory tracts are collections of lots of small fibres
-

6

temporal lobe responsible for..

- adutiroy area
- vestibular concious perception
- pyriform lobe olfactory and limbic system (emotion)

7

frontal lobes responsible for..

- mainly motor area
- corticospinal and corticonuclear tracts of CONTRALATERAL body

8

parietal lobes repsonsible for..

sensory mainly, some motor areas (or to motor areas? hard to tell from notes..)

9

occipital lobes responsible for..

visual concious perception

10

Outline the visual pathway

- Retina
- optic nerve [retinal ganglion cells, glial cells and meninges, myelinated extension of the brain]
- optic chiasm (lateral retina remains ipsilateral, medial retina decussates)
- optic tract
- lateral geniculate nucleus
- optic radiation
- occipital lobe

11

What is papilloedema?

- bulging of the optic nerve into the vitreous d/t optic neuritis

12

Outline the path of the menace response

- visual pathway
-occipital lobe association fibres to motor cortex
- projection fibres to PONTINE nucleus in pons (brainstem)
- transverse fibres to contralateral cerebellar cortex
- efferent cerebellar fibres to facial nuclei
- facial nerve to obicularis oculi m.
- blink

13

When may the menace be absent for reasons other than tract problems?

- first 10-12 weeks (learned response)
- stressed
- lethargic
- disorientated patients

14

CLinical signs of forebrain dysfunction

> mental status
- altered (depression/delerium/confusion/stupor/coma)
- behavioural changes ( thalamic) eg. hemi-neglect syndrome where one visual FIELD is lost [eg. will only eat half of dinner etc.]
> seizures
- always indicate forebrain involvement by definition
> gait
- normal OR
- head pressing
- body turn [pleurothotonus], head turn or circling towards side of lesion
> postural reaction deficits
- loss of concious postural reactions (eg. paw placement) on contralateral limb to lesion
> decreased facial sensation
- contralateral to lesion
- trigem branches all 3 have sensory component (+ mandibular has motor)
- pathway to parietal and frontal lobes
> NORMAL spinal reflexes
- (unless multifocal dz causing them elsewhere)

15

Which side of the brain do visual deficits in hemi-neglect syndrome indicate the lesion is on?

opposite side to visual defect side

16

Which side is the lesion with a left head turn?

Left

17

What type of ataxia does forebrain involvmenet cause?

proprioceptive

18

What are the 3 branches of trigem? Which are sensory and which are motor?

opthalmic
maxillary
mandibular
- all sensory
- mandibular only = motor to mm. of mastication

19

Which parasite can cause ^Intracranial pressure in the cat?

- Taenia parasitic cysts
- ^ ICP squashes cerebellum
-> transtentorial herniation and herniation of cerebellum through foramen magnum

20

slides of tx of cases supposed to be put on learn???

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