Bio 161 Exam 3 Questions and Correct Answers

Secretion definition - the process of converting an electrical signal (presynaptic neuron) to a chemical signal (synapse) and then back to an electrical signal (post synaptic neuron) Synaptic Activity - allows neurons to communicate with one another What happens in Secretion? - the release of neurotransmitters Neurotransmitters - derived from amino acids (dopamine or norepinephrine) - derived from gas (acetylcholine) - carries chemical signal/messages Vesicle - stores neurotransmitters - transport down axon to synapse and then back to cell body for recycling - made of microtubules Neurotransmitters released from a presynaptic cell bind to ______protein channels located in the membrane of the postsynaptic cell. chemical-gated How many synapses may occur between pre-synaptic and post-synaptic neurons? hundreds to thousands Summation - the total (sum) of all local potential charges at the synapses of a post synaptic cell Excitatory Postsynaptic Potential (EPSP) - cause depolarization of a post synaptic neuron - local Na+ Inhibitory Post Synaptic Potential (IPSP) - cause hyperpolarization of post synaptic neuron - local K+ What channels would open in a postsynaptic cell during an EPSP (before threshold is reached)? Sodium chemical-gated Components of Summation - one component of integration - interneurons and motor neurons receiving information from multiple cells and summing the change to determine if an action potential is initiated