Cerebral Cortex and Cerebellum

Question 1

pyramidal cells

Answer 1

• long apical dendrite and a basal dendrite-extend thru the layers of the cerebral cortex
• axons leave cortex, EXCITATORY GLUTAMATE
• **DENDRITIC SPINES are selectively modified by learning

Question 2

non-pyramidal cells

Answer 2

• axons do NOT leave cortex; INHIBITORY GABA
• INTERNEURONS of the cerbral cortex

Question 3

How many layers does the neocortex have on histologic appearance

Answer 3

• six layers
• agranular areas-most LARGE pyramidal cells (lighter)
• granular areas (koniocortex)-predominantly small neurons
• layer 1: superficial, molecular layer
• layer 2,3,4: COME IN
  
  • 2: external granular
  • 3: external pyramidal
  • 4: internal granular
• layer 5,6: LEAVE
  
  • 5: BS, SC, corticostriate
  • 6: thalamus
• they are are lined up in functional colums and get specific types of afferent info

Question 4

cerebral gyri and brodmann areas

Answer 4

• rolandic fissure: F/P
• sylvian fissue: T/F+P
• introparietal lob: superior and inferior P
• cingulate gyrus-medial
• P-O fissure-medial
• calcarine fissure-media

Question 5

Connections

Answer 5

• **corpus callosum-projects from cortical area to mirror image (+other areas)
  
  • genu and anterior body-frontal lobes
  • posterior body: parietal lobe
  • splenium: O + T
• anterior commissure-interconnects T+component of olfactory (left to right side)

Question 6

Association bundles or fasciculi

Answer 6

• corticocorticl connections in the same hemisphere
• none are discrete pt-to-pt
• fibers travel in both directions, leave and enter
• main ones:
  
  1. cingulum (medial)
  2. superior OF
  3. superior longitudinal (arcuate)-band of white matter connects areas of all 4 lobes
  4. inferior OF
  5. uncinate

Question 7

Neocortical areas

Answer 7

• injuries in certain areas give SPECIFIC deficits
• areas are specialized for DIFFERENT FXNS
  
  • sensory, motor, association, and limbic areas
  • fxn is a relationship of the arrangement of neurons within there, the afferent that enters, and efferent projections out
• relationhip between BRODMANN’s number and fxn

Question 8

PRIMARY neocortical areas

Answer 8

• some things (hands) are hyperaccentuated, otherwise its just 1:1
• inputs form thalamic nuclei and outputs to brainstem and SC
  
  • primary motor: precentral 4
  • primary somatosensory: postcentral 312
  • primary visual: calcarin 17
  • primary auditory: transverse temporal gyrus 41
  • primary gustatory: anterior insula

Question 9

Unimodal association areas

Answer 9

• more complex response functions
• adjacent to primar cortical areas, same fxn, les sprecise body map…“add extra meaning”
• injury can cause AGNOSIA (inability to interpret sensations and hence to recognize things)
• premotor 6-involves larger groups of muscles in an activity
  
  • supplementary motor 6-assumption of postures or using muscle son both sides of the body

Question 10

MULTI-modal association areas

Answer 10

• HIGH LEVEL INTELLECTUAL FXNS
• assocition areas send converging inputs, may respond to mulitple stimuli or under particular circumstances
• injury can causes an APRAXIA (motor)-injury to L. P or NEGLECT (sendory)-injury to R. inferior P
• Prefrontal area-working memory and decision maing
  
  • ​dorsolat: working memory, attn, prob solve
  • ventromed: emotional pt of planning and decision
  • exec fxns: plann, insight, foresight, personality
• Limbic area-emotional and drive related behaviors
  
  • ​around the hippocampal area-tip of the mitten and medial along the corpus callosum

Question 11

Classical language localization

Answer 11

• BROCA (motor): non-fluten, good comp
• WERNICKE (sensory): fluten, POOR comp

Question 12

reticular formation roles

Answer 12

• coordinates motor and sensory brainstem nuclei
  
  • pattern generator:
    
    • eye movements: horizontal (PPRF) nd vertical (riMLF)
  • respiratory control-medulla
  • CV control-medulla
  • sensory modulation/gate control of pain (nucleus raphe magnus)

Question 13

What are the three layers of the cerebellum

Answer 13

1. molecular layer
   
   • mainly axons and dendrites
   • basket cells-axons synapse on pukinje cell body
   • stellate cells=axons synapse on Purkinge cell dendrites
2. Purkinje cell layer-predominant OUTPUT from the cerebelly
   
   • Purkinje cells-ONLY AXONS that leave the cerbellar cortex
3. Granular layer (dense)
   
   • granular cells-send their axons into the molecular layer as parallel fibers
   • white matter underneath