Cerebellum, third and fourth ventricle Flashcards

1
Q

why is cerebellum the largest part of the hindbrain?

A
  • it accounts for 10% of the brain’s volume

- consists of most the neurons

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2
Q

what is the function of cerebellum?

A

coordination of movement and balance

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3
Q

what is the function of vermis?

A

it joins the two ovoid hemisphere in the midline of the cerebellum

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4
Q

what are the peduncles?

A

it attached the brainstem to each side of cerebellum

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5
Q

what is the function of cerebral aqueduct?

A

it runs through the midbrain and connects the third and fourth ventricles

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6
Q

how do you identify these structures?
red nucleus
substantia nigra

A

red nucleus - a circular mass of grey matter that is ventro lateral to the cerebral aqueduct
substantia nigra - a black band of nerve cells overlying the crus cerebri, ventrolateral to the red nucleus on each side

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7
Q

how would you identify the tonsil on cerebellum?

A

a prominent rounded swelling on cerebellum anteriorly and medially on either side of the vermis

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8
Q

what is the significance of flocculo-nodular lobe?

A
  • flocculus (laterally) connected to nodule (medially, below vermis) is called floccular nodular lobe
  • it is essential because it concerned with vestibular formation (which is associated with equilibrium)
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9
Q

which parts of the BS does the superior, middle and inferior cerebellar peduncles connect with?

A

superior cerebellar peduncle - connects the cerebellum to midbrain
middle cerebellar peduncle - connects the cerebellum to pons
inferior cerebellar peduncle - connects the cerebellum to medulla oblongata

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10
Q

what is the function of spinocerebellar tracts?

A

spinocerebellar - sensory input for balance and position;

  • 2 types: dorsal and ventral
  • dorsal spinocerebellar tract - ipsilateral: travels to inferior cerebellar peduncle
  • ventral spinocerebellar tract - contralateral: travels to superior cerebellar peduncle
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11
Q

what is the function of vestibulocerebellar and corticopontocerebellar tracts?

A

vestibulocerebellar tract - vestibular impulses from labyrinth directly - travels to the inferior cerebellar peduncle
corticopontocerebellar (rubrothalamic) tract - information from motor cortex of motor plan, the same information goes to spine - travels to the middle cerebellar peduncles

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12
Q

which is the largest cerebellar nuclei and what is its function?

A
  • dentate nucleus: most lateral of deep cerebellar nuclei
  • zig-zag edged oval mass
  • major fibres pass into the superior cerebellar peduncle
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13
Q

what is the rhomboid fossa?

A

it is diamond shaped floor of IVth ventricle limited laterally by cerebral peduncles and posteriorly by gracile and cuneate tubercles

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14
Q

what is the function of median sulcus on the floor of IVth ventricle?

A

divides the rhomboid fossa into triangular left and right halves

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15
Q

where to find the following with the respect to the cranial nucleus?

  1. vestibular trigone
  2. vagal trigone
  3. hypoglossal trigone
  4. facial collucli
A
  1. vestibular trigone - lateral triangular area overlying the CN8 nucleus
  2. vagal trigone - intermediate triangular area overlying the overlying the CN10 nucleus
  3. hypoglossal trigone - medial triangular area overlying the CN12 nucleus
  4. facial collucli - rounded swelling on pons, the facial nerves passes over it but has the facial nerve nuclei
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16
Q

where can you find the obex?

A

at the inferior apex of rhomboid fossa

17
Q

what is the area posterma? and why is it important?

A
  • a small tongue shaped area anterior-lateral to the obex

- associated with nausea control, a chemoreceptive trigger zone for emetic (vomiting) response

18
Q

what is the function of the following sulcus?

  1. central sulcus
  2. parieto-occipital sulcus
  3. calacrine sulcus
A
  1. central sulcus - separates the frontal and parietal lobe
  2. parieto-occipital sulcus - separates the parietal and occipital lobe
  3. calcarine sulcus - separates the occipital and temporal lobe
19
Q

what is the function of interventricular foramen?

A
  • allows the CSF flow from lateral ventricles to 3rd ventricle
  • it is filled filled with choroid plexus
20
Q

what is corpus callosum? what is the function of corpus callosum?

A
  • it is a broad arched band of white matter

- the largest of fibre bundles connecting the two halves of the brain

21
Q

what are the four main regions of corpus callosum?

A
  1. genu - the anterior curved of CC
  2. rostrum - below the genu
  3. body - the central part of CC
  4. splenium - the posterior rounded end of CC
22
Q

what is fornix and what is its function?

A
  • a bundle of white fibres under the corpus callosum

- connects the hippocampus with the diencephalon and pre-commisural fibres

23
Q

where is thalamus? what is its function?

A
  • at the dorsal part of diencephalon

- major subcortical relay station for information ascending to the cerebral cortex

24
Q

where is hypothalamus?

A
  • at the ventral part of diencephalon

- contributes to the body homeostasis, control the autonomic nervous and neuroendocrine systems

25
what connects different area of the cortex?
myelinated axons
26
what are the main types of fibres and what are its functions?
1. association fibres: links cortical regions in one cerebral hemisphere 2. commissural fibres: links similar function region in two hemisphere e.g. corpus callosum 3. projection fibres: links cortex with subcortical regions such as the thalamus and SC via the internal capsule and corona radiata
27
what are the two basic functions of cerebral hemisphere?
1. to bring together the separate representations of two halves of the brain, the visual and auditory system 2. to unite areas of cortex which have functions specialised to one hemisphere
28
which one is dominant hemisphere and what is it responsible for?
left hemisphere is dominant and is responsible for language | right hemisphere is non-dominant
29
what happens if the corpus callosum is damaged?
- this would demonstrate sperry split brain phenomenon - each hemisphere would behave autonomously - lack of cross integration where the second hemisphere does not know hat the first hemisphere is doing - for e.g. if a reading and naming stimuli is presented to the left visual field, the individual are unable to read/write/name as this would be directed to the right hemisphere (non-dominant) which does not evoke a verbal response
30
what is the function of superior and inferior collucli?
superior collucli - visual system through lateral geniculate body inferior collucli - auditory system through medial geniculate body
31
what is the difference between primary fissure and horizontal fissure?
primary fissure - seperates anterior lobe and posterior lobe | horizontal fissure - seperates middle and posterior lobe
32
how to identify the following? 1. basilar sulcus 2. bulbopontine sulcus 3. anterior median fissure 4. pyramids 5. olive
1. basilar sulcus - on the midline of pons 2. bulbopontine sulcus - junction b/w pons and medulla 3. anterior median fissure - divides the medulla 4. pyramids - medially 5. olive - laterally
33
how to identify the gracile and cuneate tubercles?
- below the rhomboid fossa - dorsal column nuclei, involved in medial lemniscus pathway - gracile tubercle - medial, lower limbs - cuneate tubercle - lateral, upper limb
34
what is the significance of medullary striae?
divide the floor of ventricle into rostral pontine half and caudal medullary half
35
where is locus coerulus? and what is its function?
- behind rostral pons | - function: produces NA - stress response + arousal
36
where to identify the anterior commissure?
below the anterior end of fornix
37
Outline the pathway of CSF flow
Lateral ventricle -> interventricular foramen (foramen of munroe) -> third ventricle -> cerebral aqueduct -> fourth ventricle -> central canal -> subarchanoid space
38
where is the crus cerebri?
anterior portion of cerebral peduncle contains the motor tracts, travelling from cerebral cortex to pons and spine
39
where to identify the anterior and posterior commissure?
anterior commissure - in front (anterior) of the columns of fornix, connects the two hemisphere posterior commissure - below the fornix in the third ventricle