Cells communicate with each other through direct contact
Cells of multi-cellular organisms (like humans) often maintain physical contact with each other
Some unicellular organisms live in colonies and make contact with each other in the colony
Cells can send chemical signals into nearby cells
Cell membrane and cell wall modifications allow for communication to occur between nearby cells
Cells can communicate over long or short distances
Cells use chemical signals to communicate over long & short distances
The cell receiving the signal is known as the target cell
Cells send out signals, Target cell is within a short distance of the signal, Often used to communicate with cells of the same type
Short Distance Communication
Long Distance Communication
Target cell is not near the cell sending out the signal, Signal travels a long distance to reach the target cell, Often used to communicate with cells of different types
Immune/Healthy cells often communicate through cell-to-cell contact
The cells of multi-celled organisms must communicate with one another to coordinate the activities of the organism as a whole.
There are 3 stages of cell communication: reception, transduction, and response
Reception: Detection of the signal coming from outside the cell
Transduction: Converting the signal to a form that can produce a response
Response: Specific cellular response to the signal received
