Cell Communication

Cell-cell communication

Critical for the function and survival of cells, responsible for the growth and development of multicellular organisms.

Three general ways cells communicate

Direct contact, Local signaling, Long-distance signaling.

Direct contact communication

Communication through cell junctions where signaling substances pass freely between adjacent cells.

Gap junctions

Specialized cell junctions in animal cells that allow direct communication.

Plasmodesmata

Cell junctions in plant cells that facilitate communication between cells.

Ligand or Local Regulators

Chemical messages released by a secreting cell that travel a short distance through the extracellular fluid.

Paracrine signaling

A form of local signaling where a cell acts on nearby target cells.

Synaptic signaling

Local signaling that occurs between nerve cells.

Hormones

Chemical signals used by animals and plants for long distance signaling.

Endocrine signaling

Hormones released into the circulatory system to interact with target cells.

Stages of cell signaling

Reception, Transduction, Response.

Reception stage

Detection and receiving of a ligand by a receptor in the target cell.

Signal transduction pathway

A sequence of changes in molecules that regulates protein activity and converts an extracellular signal to an intracellular signal.

Second messengers

Small, non-protein molecules and ions that help amplify the response in a signaling pathway.

Response stage

The final molecule converts the signal to a cellular response, which can alter membrane permeability, metabolic processes, or gene expression.