myelinated fibers

fibers and tracts of cerebrum

the ways that regions of the cerebrum talk to each other

• myelinated fibers

  • communication link among the neurons

types of fiber tracts in CNS

1. projection fibers

2. association fibers

3. commissural fibers

projection fibers

efferent and afferent tracts that course between the cerebral cortex and brainstem or spinal cord

• connect cortex with distant locations 

projection fibers: corona radiata

fibers from and to the corext

• condenses nearly all afferent and efferent fiber sinto small area: intointeral capsule

internal capsule

contains ascending and descending tracts

• transmits info from primary motor cortex to lower motor neurons in spinal cord

• lesions: weakness of arm, face (chew and swallow)

• anterior (frontal lobe) and posterior

corticobulbar

for communication with brainstem and cranial nerves

corticospinal

for communication with spinal cords

associations fibers

two types (short and long) → both connect regions within same hemisphere

short association fibers

• arcuate fasciculus

• uncinate fasciculus

• cingulate gyrus

• superior longitudinal fasciculus

• inferior longitudinal fasciculus

arcuate fasciculus

connects frontal and temporal language areas