Unit 4: Topic 1 - Cell Communication Flashcards
Explain how immune cells benefit from communication via contact.
Immune cells are able to detect antigens that are present on the surface of a cell. Using the information given to them by the contact, they can then provide the correct response to that specific foreign body.
What are the three main ways cells can directly communicate via contact with one another, and explain what they are.
Cells can use one of three techniques: gap junctions, desmosomes, and tight junctions.
Gap Junction: A tube forms between two cells that allows for the transport of water/ions. This method also has functions in specific areas, such as cardiac tissues, to help create heartbeats.
Desmosome: Thin fibers connect two cells. These fibers do not allow any transport between the two cells; however, these fibers keep the cells together while not compromising their ability to absorb nutrients.
Tight Junction: Cells squish together and the membranes connect. This connection is an impermeable barrier and does not allow for the transportation of fluids.
How do cell junctions work when cells have a cell wall?
These junctions work by using plasmodesmata. They are just little holes punched between adjacent cells in a plant.
What are the three main ways cells can directly communicate via short distances with one another, and explain what they are.
Cells can use one of three techniques based on distance: Juxtacrine, Paracrine, and Endocrine signaling.
Juxtacrine: Cells that are in contact with one another can send signals. For example, two cells growing on a surface can signal to one another to stop growing by sending chemicals to the other cell’s receptor site.
Paracrine: Cells that are in the same region can send signals to each other. For example, paracrine signaling happens whenever a neuron releases neurotransmitters into the area between itself and another neuron (a synapse), and the other neuron receives the signal.
Endocrine: Cells communicate over large distances. For example, the adrenal glands can secrete adrenaline to help speed up the heart rate of someone in a fearful situation.
