Lectures 9 & 10 (cortex, deep nuclei + diencephalon, brainstem, cerebellum))

Question 1

grey matter vs white matter in different sections of CNS

Answer 1

Cerebral cortex:
- grey on outside (somas/cell bodies)
- white on inside (axons)
- deep grey matter (thalamus + basal nuclei)
Spinal cord
- white on outside
- grey on inside

Question 2

names for grooves vs bumps on brain (names, notable ones)

Answer 2

fissures (deep grooves)
- longitudinal fissure (separate L&R)
- lateral/sylvian fissure (separate upper & temporal)
sulci (shallow grooves)
- central sulcus (separate frontal & parietal)
gyri (bumps)

Question 3

lobes of the brain

Answer 3

• frontal
• parietal
• occipital
• temporal
• insula/insular lobe

Question 4

primary cortex’s

Answer 4

• primary motor (posterior frontal lobe)
• primary sensory (anterior parietal lobe)

Question 5

Arterial blood supply to brain

Answer 5

anterior cerebral artery: superior middle of brain
middle cerebral artery: lateral portions of brain
posterior cerebral artery: inferior portion of brain

Question 6

frontal lobe cortex + areas

Answer 6

• prefrontal
• premotor
• primary motor
• frontal eye field
• Broca’s area (physical aspects of speech) *only on left
• *olfactory cortex (also temporal)

Question 7

parietal lobe cortex + areas

Answer 7

• primary sensory
• somatosensory (voluntary)
• *Wernike’s area (also temporal, non-physical aspects of speech) *only left

Question 8

temporal lobe cortex + areas

Answer 8

• primary auditory cortex
• *Wernike’s area (also parietal, non-physical aspects of speech) *only left side
• *olfactory cortex (also frontal)

Question 9

occipital lobe cortex + areas

Answer 9

• visual cortex
• primary visual cortex

Question 10

deep cerebrum structures + cortex’s

Answer 10

• insular cortex (balance, emotional context to sensation)
• primary gustatory cortex
• cingulate gyrus (emotional + behavioural processing)
• corpus callosum (connects R&L lobes)
• internal capsule

Question 11

purposes of left vs right brain

Answer 11

L - Logical
- movements + sensation on right
- spoken and written language
damage can lead to aphasia (loss of language)
R - Creative
- movements + sensation on left
- spacial orientation + object recognition
damage can lead to loss of emotional component of speech

Question 12

types of white matter fibres

Answer 12

• commissural fibres (between hemispheres)
• association fibres (between lobes)
• projection fibres (to different part of CNS) eg: brain to spinal cord

Question 13

Basal nuclei (location, purpose, anatomical structures)

Answer 13

• lateral to ventricles
• initiate, coordinate + stop motor movement
• skill/muscle memory (eg: walking)
• dopamine is the main neurotransmitter
• caudate nucleus (head + tail)
• striatum (between caudate and putamen)
• lentiform nucleus (putamen + globus pallidus)
• substantia nigra

Question 14

Basal nuclei neural pathway

Answer 14

cortex –> basal nuclei –> thalamus –> cortex

Question 15

Basal nuclei pathology

Answer 15

• Huntington’s chorea: neurodegeneration of striatum, cannot inhibit motion, increased movements
• Parkinson’s: diminished substantia nigra neurons, hard to start/stop movements

Question 16

Limbic system (anatomical structures + pathway)

Answer 16

• amygdala
• hippocampus
• fornix
• mammilary bodies
  After:
  anterior thalamic nuclei —> entorhinal cortex —> thalamus –> prefrontal cortex + cingulate gyrus –> amygdala (memories)

Question 17

role of hippocampus

Answer 17

consolidate and encode memories (short term)

Question 18

role of amygdala + pathologies

Answer 18

• threat detection/assessment, can evoke fight or flight response via ANS + Endocrine
  Damage: inability to recognize fearful situations, loss of emotional memories + inhibition
  Abnormal activation: PTSD, panic disorder, GAD

Question 19

types of amnesia

Answer 19

• anterograde: can’t form new memories (long term still in-tact, muscle memories can still be formed)
• retrograde: loss of long term memories

Question 20

Diencephalon (structures + functions)

Answer 20

• posterior pituitary gland (*anterior not connected by neurons)
• hypothalamus (ANS regulation)
• thalamus (gateway nucleus, selective attention)
• pineal gland (sleep + circadian rhythms)

Question 21

Specific purposes of thalamus

Answer 21

• memory: links mammillary bodies to cingulate cortex
• motor: balance between basal nuclei and cerebellar output
• sensations: all except smell

Question 22

thalamic syndrome

Answer 22

stroke affecting thalamus (eg: posterior artery blockage), contralateral loss of sensation (ALL, except smell)

Question 23

regions of the brainstem

Answer 23

• midbrain
• pons
• medulla

Question 24

Anterior brainstem anatomy

Answer 24

• cerebral peduncles
• middle cerebellar peduncle
• olive
• pyramidal tracts
• pyramidal decussation

Question 25

Posterior brainstem anatomy

Answer 25

- superior colliculi (vision reflex relay) - inferior colliculi (auditory reflex relay) - cerebellar peduncles - somatosensory tracts

Question 26

cranial nerves (above pons)

Answer 26

1 - olfactory I 2 - optic II 3 - oculomotor III 4 - trochlear IV

Question 27

cranial nerves ('on' pons)

Answer 27

5 - trigeminal V 6 - abducens VI 7 - facial VII 8 - vestibulocochlear VIII

Question 28

cranial nerves (below pons)

Answer 28

9 - glossopharyngeal IX 10 - vagus X 11 - spinal accessory XI 12 - hypoglosseal XII

Question 29

Reticular activating system (purpose + tract)

Answer 29

sensory stimuli to help regulate conciousness, alertness and sleep via reticular formations in brain stem

Question 30

Cerebellum (structures)

Answer 30

*lateral sections for lateral control - anterior lobe* - posterior lobe* - flocculonodular lobe (eye movements) - vermis (axial control)

Question 31

cerebellar peduncles (purpose)

Answer 31

superior: cerebellum to brainstem middle: cortex to cerebellum inferior: spinal cord to cerebellum (eg: proprioception)

Question 32

Appendicular pathway (cerebellar)

Answer 32

Loop: Cortex - contralateral to desired motion *Midbrain - cerebral peduncle (cross to ipsalateral) Pons - pontine nuclei Cerebellum - from middle cerebellar peduncle, out superior CP Midbrain - red nucleus *Thalamus - cross to contralateral Cortex - contralateral --> corticospinal tract

Question 33

Axial pathway (cerebellar)

Answer 33

Up to cortex: Spinal cord - spinocerebellar tract Cerebellum - from inferior cerebellar peduncle, out superior CP Midbrain - cerebral peduncle *Thalamus - cross to contralateral Cortex --> vestibularspinal tract (same as cortico but skips thalamus)

Question 34

Cerebellum pathologies

Answer 34

Ataxia - medial cerebellum (difficulties stabilizing trunk) Intention tremor - lateral cerebellum (difficulty executing motions)