The Similarity: Pyramidal and extra-pyramidal system are the descending tracts (motor tracts) of spinal cord.
The Difference:
1) Their tracts -
- Pyramidal system = lateral and anterior corticospinal tracts + corticobulbar tract
- Extra-pyramidal system = rubrospinal + olivospinal + lateral and medial reticulospinal + tectospinal + vestibulospinal tracts
2) "Extrapyramidal tracts" don't reach their targets by traveling through the "pyramids of medulla". Pyramidal tracts go through the pyramids of medulla.
3) Pyramidal tracts may directly innervate motor neurons of spinal cord or brainstem (anterior horn cells or certain cranial nerve nuclei). But, extrapyramidal tractsindirectly control the anterior horn cells (for modulation and regulation)
4) Pyramidal system is responsible for fine, isolated, precise and specific movements. Extrapyramidal system is responsible for gross, syngergic movements which require the activity of large groups of muscles