BIOCHEM 2EE3 Study Guide - Final Guide: G Protein–Coupled Receptor, Voltage-Dependent Calcium Channel, Axon Terminal
Document Summary
Dendrites = receive info from another cell and transmit message to the. Cell body = contains nuc, met, and other organelles. Axon = conducts electrical signals away from body. Sensory ( afferent) - carry to cns. Motor (efferent) - carry away from cns to effector. Unequal distribution of cations and anions in cytosol and in extracellular uid causes difference in electric potential across the membrane. Potassium higher inside cell therefore sodium higher outside cell. The axon plasma membrane = k and na channels = integral proteins = normally closed. Na/k atpase maintains unequal concentrations by transporting ions against concentration gradient. When na and k are open, pass through according to gradient. The changed ionic distribution tigers change of membrane potential = action potential. Beginning at spot on membrane then spreads down the membrane. During brief moment of passage of potential - membrane cannot be stimulated again.