Question

Depolarization of one group of smooth muscle cells rapidly spreads to other smooth muscle cells, leading to coordinated contractions. This electrical coupling is due to

• A. autocrine signaling

• B. paracrine signaling

• C. endocrine signaling

• D. direct signaling

Answer 1

ANSWER - (4) DIRECT SIGNALLING

direct signalling is the signalling between the neighbouring cells by the helps of gap junctions in animal cells and plasmodesmata in the animal cells.

It is the cell signalling done directly through the gap junctions.

so one group of smooth muscles spreads to other leading to contraction is the direct signalling through gap junctions.

autocrine signalling the signalling done to own by the cell through the ligand that binds on a rceptor of own surface and so no neighnour signaling is seen here.

while paracrine signalling is done between the near by cells by the release of chemical messengers and this is done to invite nearby cells.

and endocrine signalling is done chemical messengers by the help of ligand with the cells which are very far from the cells these ligands are released in the circulation and reach to the destination molecules.

and so these smooth muscles raoidly spreads with neighbour smooth cells with gap junctions direct with direct signalling.