BSC 2011 Lecture 13: Animals lecture 13
Document Summary
Ganglia -neurons organized into clusters, often paired. Brain- largest pair of ganglia, found in animals with complex behavior. Nervous systems have 2 categories of cells: neurons generate and transmit electrical signals called action potentials. Axon-conducts action potentials away from cell body; can be very long. Presynaptic axon terminals: glia provide support and maintain extracellular environment. Synapse-gap where two neurons (or neutron and muscle cell) communicate. 3 stages of information processing: afferent (sensory) neurons-info is sent from sensory cells to brain, interneurons-info is received at ganglia and integrated, stored and transmitted, efferent (motor) neurons. Neurons have membrane potential (difference in electrical charge) across cell membrane. Action potential -sudden large change in membrane potential. Difference in ionic charge between inside and outside of cell establishes membrane potential. Neuron that is not singling, resting potential is approx. Transport proteins in membrane create concentration gradients. Sodium-potassium pump-moves na+ ions from inside, exchanges for k+ from outside: moving ions against concentration gradient require energy.