Examination of Cerebrum and Meninges Flashcards
Total surface area of the cerebral cortex
2.5 sq.ft.
Total weight of the brain in Adults
1400gms
Total number of neurons in cerebral cortex
10 Billion
Total number of synapses in cerebral cortex
60 trillion
Total weight of the brain in newborns
400 gms
Transmission and transmission speed
30-360 ft/sec
Number of neurons
10^11to 10^12neurons
Based on studies of stained cells
Cytoarchitectonic organization
Based on studies of myelinated fiber preparations
Myeloarchitectonic organization
Layer I of Cytoarchitectonic Organization
Principal Cells
Principal Fibers
Molecular
C: Axons & dendrites
F: Association and commisural fibers Source of corticocortical fibers
Layer II of Cytoarchitectonic Organization
Principal Cells
Principal Fibers
External granular
C: Small pyramidal cells
F: Association and commisural fibers
Source of corticocortical fibers
Layer III of Cytoarchitectonic Organization
Principal Cells
Principal Fibers
External Pyramidal
C: Medium pyramidal cells
F: Association and commisural fibers
Source of corticocortical fibers
Layer IV of Cytoarchitectonic Organization
Principal Cells
Principal Fibers
Inner Granular
C: Stellate cells
F: Thalamocortical
Where most incoming signals go to
Layer V of Cytoarchitectonic Organization
Principal Cells
Principal Fibers
Inner Pyramidal
C: Large pyramidal cells
F: Corticobulbar, corticospinal & corticostriatal
Mostly outgoing fibers
Layer VI of Cytoarchitectonic Organization
Principal Cells
Principal Fibers
Polymorph
C: Fusiform cells
F: Source of corticothalamic fibers
Layer I of Myeloarchitectonic Organization
Fibers
Tangential
F: NA
Layer II of Myeloarchitectonic Organization
Fibers
Dysfibrous
F: NA
Layer III of Myeloarchitectonic Organization
Fibers
Suprastriatal
F: Cortico-cortical
Layer IV of Myeloarchitectonic Organization
Fibers
External Baillarger
F: Thalamic projection
Lines of Gennari
Layer V of Myeloarchitectonic Organization
Fibers
Internal Baillarger
F: Corticostriate
Layer VI of Myeloarchitectonic Organization
Fibers
Infrastriatal
F: Cortico-thalamic
Frontal Lobe
Initiation of voluntary movements
Primary motor cortex (pre-central gyrus)
Frontal Lobe
voluntary movements
Pre-motor area (pre-central + superior and middle frontal gyri)
Frontal Lobe
motor control of speech
Broca’s area (inferior frontal gyrus, dominant lobe)
Frontal Lobe
personality, insight and foresight, emotion
Prefrontal cortex
BA 4
Primary motor area
Location of BA 4
Precental gyrus, paracentral lobule
BA 6
Premotor area
Location of BA 6
Superior, middle frontal gyri, precentral gyrus
BA 8
Frontal eye field