C5 - Telencephalon

Question 1

Define telencephalon

Answer 1

Telencephalon = cerebrum

Forebrain (with diencephalon)

Cerebrum is the largest part of the brain, and lies either in front or on top of the brain stem

Question 2

Which terms should be included?

Answer 2

Telencephalon = cerebrum

• Lamina terminalis
• Cerebral hemisphere (2 stk)
  
  • Frontal lobe
  • Occipital lobe
  • Temporal lobe
  • Parietal lobe
• Cerebral cortex
  
  • Gyrus
    
    • Cingulate gyri
  • Sulcus
    
    • Cruciate sulcus
    • Coronal sulcus
• White matter
  
  • Corpus callosum
  • Internal capsule
• Basal nuclei
  
  • Caudate nuclei
• Lateral ventricle
  
  • Interventricular formen
  • Choroid plexus

Question 3

What does the telencephalon consists of?

Answer 3

• 2 cerebral hemispheres (divided by the medial longitudianl fissura)
  
  • They are connected across the midline by fibers that form corpus callosum:
    
    • ​Rostral comissure of the hippocampus
    • Dorsal comissure of the hippocampus
    • Ventral comissure of the hippocampus
• Cerebral cortex
  
  • Paleophallium (olfaction)
  • Archipallium (makes up the hippocampus in humans)
  • Neopallium (predominant part of the cerebellum)

Question 4

Cerebral hemispheres

Answer 4

• 2 cerebral hemispheres divided by the medial longitudianl fissura
• They are connected across the midline by fibers that form corpus callosum:
  
  • ​Rostral comissure of the hippocampus
  • Dorsal comissure of the hippocampus
  • Ventral comissure of the hippocampus

Question 5

Cerebral cortex

Answer 5

• Outer layer of grey matter of the cerebrum. The surface have folds to create gyri and sulci increasing the surface area
• Divided into:
  • Paleopallium (olfaction)
  • Archipallium (makes up the hippocampus in humans)
  • Neopallium (the predominant part of cerebrum)

Question 6

Cerebral cortex: paleopallium

Answer 6

• Ventral part of each hemisphere
• Olfaction
• Separated from neopallium by sulcus rhinalis medialis (medial olfactory grooce: separates pedunculus olfactorius from neophallium)
• Rostrally: bulbus olfactorius (fits into the recess of os ethmoidale)
  
  • Continued caudally by tractus olfactorius commuis → tractus olfactorius medialis et lateralis​,separated bytrigonum olfactorium
    
    • ​Tractus olfactorius medialis
      
      • ​Runs towards medial aspect of the hemisphers
      • Some of the continuign fibers terminate within certain cortical gyra, other pass through comissura rostralis
      • Comissura rostralis:
        
        • ​Rostral wall of 3^rd ventricle
        • Bridge of white matter which connects the right and left rhinencephalon
    • Tractus olfactorius lateralis
      
      • ​Continues caudally to join the large lobus piriformis
• Lateral: bulbus piriformis
• Medial: commissura rostralia

Question 7

Cerebral cortex: neopallium

Answer 7

• “Youngest part” of pallium
• Major part of telencephalon
• Location:
  
  • Forms the dorsolateral part of each hemisphere
  • Interposed between the ventral paleopallium and the medial archipallium
• Divided from paleopallium by sulcus rhinans medialis
• Divided from archipallium by sulcus splenialis
• On surface: gyri and sulci (role: increases surface size)
• Lateral side: sulcus sylvius
• Cruciate groove: extends from longitudinal cerebral fissure, running transversly on the rostrodorsal aspect
• Transverse cerebral groove: separates the cerebrum from the cerebellum
• 4 lobes:
  
  • Frontal lobe (motor area)
    
    • ​​→ motor cortex ​→ spinal cord ​→ skeletal muscle
    • → sensory cortex​
    • ​→ prefrontal cortex​ ​→ emotion, cognition function
  • Temporal lobe (auditory area)
    
    • ​​→ auditory cortex
  • Parietal lobe (sensory area)
    
    • ​​→ motor/somesthetic sensory cerebral cortex ​→ pain
  • Occipital lobe (visual area)
    
    • ​→ visual cortex

Question 8

Basal nuclei

Answer 8

• Basal ganglia: a group of subcortical nuclei (cells) responsible for motor control
• Location: dorsal to paelopallium
• Corpus striatum: number of them combine with white substance
• Caudate nucleus
  
  • ​Protrudes at rostral part of floor of lateral ventricle
  • Comma shaped: head, body, tail
• Lentiform nucleus
  
  • ​Divided by fibrous intersection into:
    
    • Globus pallidus (medial)
    • Putamen (lateral)
• Amygdala
  
  • ​Part of basal ganglion, but functionally related to rhinencephalon
  • Contains synapses to olfactory pathway
  • Located rostral to cornu temporalis of lateral ventricle, near tail of caudate nucleus
• Claustrum
  
  • ​Narrow band of grey matter, separating putamen from insula
  • Capsula on either side
    
    • White matter
    • Creats striation

Question 9

Draw the basal nuclei

Answer 9