BIOL 2410 Chapter Notes - Chapter 6: Cytosol, Cell Adhesion Molecule, Afferent Nerve Fiber
2 Nov 2017
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Document Summary
There are two basic types of physiological signals: electrical and chemical. Electrical signals: changes in a cells membrane potential. Chemical signals: molecules secreted by cells into the extracellular fluid. Target cells: the cells that respond to the secreted signals. Local communication: includes gap junctions, contact dependent signals (molecules bind to cells surface), long distance communication (uses combination of chemical and electrical signals carried by nerves or blood) Electrical and chemical signals pass through gap junctions. A gap junction forms from the union of membrane spanning proteins called connexions on two adjacent cells. United connexions create a protein channel (connexon) that can open and close. When open the conjoined cells function as one that contains multiple nuclei (a syncytium) What can pass: ions, small molecules, aas, atp, camp. There are different types of gap junctions, they vary from tissue to tissue. Contact dependent signals require cell to cell contact.
