Differnces between Single unit muscle fibre and Multi unit muscle fibre

SINGLE UNIT MUSCLE FIBRE :

1. These smooth muscles in the organ behave as one unit.
2. They have a lot of gap junctions interconnecting the cells.
3. Rhthymatically active muscle are single unit in nature.
4. Example : smooth muscles of GI tract, walls of most hollow organs, blood vessels, respiratory/ urinary/ reproductive tracts.

MULTI UNIT MUSCLE FIBRE:

1. The smooth muscles in an organ behave independently - each cell contracts and relaxes on its own.
2. They have less number of gap junctions.
3. Tonically active smooth muscle (muscles that remain contracted for most of the times) are multi unit in nature.
4. Example: Muscles of eye, walls of large blood vessels, piloerector muscle.