PHYS 1302 Lecture 1: hormones-document-silverthorn-human-physiology-an-integrated-approach
Document Summary
Composition of both boiy compartments is stable iynamic steaiy state. Steady state is not the same as equilibrium. Electrical signals are changes in a cell"s membrane potential. Chemical signals are molecules secreted by cells into ecq. Cells that respond to chemical signals are target cells. Responsible for most communication within the body. Act as ligands that bind to proteins to initiate a response. Gap junctions which allow direct cytoplasmic transfer of electrical/chemical signals between adjacent cells. Simplest form of communication is direct transfer of signals through gap junctions. Protein channels that create cytoplasmic bridges between adjacent cells. Gap junction forms the union of connexin proteins. Create protein channel that can open and close. When open, ions and small molecules (i. e. amino acids, atp, camp) diffuse directly. Larger molecules cannot pass through gap junctions. Surface molecules on one cell membrane bind to surface molecules on another cell"s membrane. Cell adhesion molecules (cams) act as receptors in cell- to-cell signaling.
