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what is the function of the nervous system? to coordinate and control multiple body function. how does the nervous system accomplish its main function? thru generation, integration and transmission of electrical signals throughout the body. neuron the basic structural component of the nervous system. also known as a nerve cell. what is the specialization function of the neuron? specialized for the ability to transmit electrical messages. dendrites "branches of the tree". they are extensions from the cell body used to receive, NOT conduct electrical signals. do dendrites generate local or action potentials? local potentials. cell body/soma metabolic control center that houses nucleus, mitochondria and synthesizes signal transmitters. what does the membrane of the cell body do? involved in signal reception and integration. axon hillock specialized region of cell between the cell body and the axon. the membrane here can "sum" local potentials and produce an action potential which can travel down the axon. axon a long untapered extension arising from the hillock area of the cell body. membrane is specialized to transmit an action potential (the signal) along its length. the terminal knob the distal region of the axon subdivides into multiple projections each of which is capped by a region of swelled cytoplasm called the terminal knob. the membrane in this region is specialized for secretory activity. name the four types of neurons. multipolar, bipolar, unipolar and type II. multipolar neuron most common type. activates motor neuron in peripheral nervous sytem. it has multiple dendrites and a single axon. bipolar neurons one axon, one dendrite. 1+ 1= 2 (bi). dendrite is usually specialized like in the eye or ear. unipolar neurons only one axon extends from the cell body. usually act as sensory neurons. type II neurons usually no axons. channels are... ion specific and regulatable. the permeability of membranes and their electrical signaling properties are controlled by... ion channels. ligand gated channel opened only in the presence of a specific channel voltage gated channel is opened by a change in the electrical properties of the membrane. what does "the spike" refer to? the fact that various agents can change the membrane's resting potential. hyperpolarization an increase in the cell's negative charge depolarization a decrease in the cell's negative charge toward zero. threshold potential a depolarization of sufficient size to open the voltage gated Na+ channels is the spike an all or nothing phenomenon? yes. b/c gated channels are either open or closed. describe the directional transmission of impulses. conduction of impulses allows forward, not back transmission. thus, the spike will travek down the length of the cell membrane. conduction without decretement the size of the ion flow is the same all along the axon. conduction speed the speed of the movement of the signal down the axon is increased by an increase in the diameter of the neuron and myelination of the axon, the synapse signals are transmitted from cell to cell over specialized structures called Synapses. what are the two types of synapses? electrical and chemical complex control processes are possible using the nervous system due to... multiple cell connections and multiple transmitters. multiple cell connections each neuron can contact many other cellls and is itself contacted by many cells. multiple transmitters different neurons produce different transmitters to which only certain cells can respond. different transmitters can also turn the same cell on or off. describe the "decision process" of each neuron. each neuron evaluates the strength, importance and type of signal information it is receiving before it decides to take action. reflex arc basic functional component of the nervous system. it is the smallest, simplest portion of the system capable of receiving a stimulus and yielding a response.