Exam 48: Neurons,Synapses,and Signalling

Use the following information to answer the next few questions. The baseball career of Lou Gehrig,a first baseman for the New York Yankees,ended once he became afflicted with amyotrophic lateral sclerosis (ALS).This disease causes the degeneration of motor neurons in the CNS,leading to rapidly progressive weakness,muscle spasticity,and atrophy.Research into the disease has shown that individuals with ALS have higher levels of the neurotransmitter glutamate in their serum and spinal fluid when compared to normal individuals. -The excitatory effect of glutamate can be found in

Receptors for neurotransmitters are of primary functional importance in assuring one-way synaptic transmission because they are mostly found on the

The activity of acetylcholine in a synapse is terminated by

In a simple synapse,neurotransmitter chemicals are received by

A chemical that affects neuronal function but is not stored in presynaptic vesicles is

Most of the neurons in the human brain are

Why are action potentials usually conducted in one direction?

The primary neurotransmitter from the parasympathetic system that influences its autonomic targets is

The following steps refer to various stages in transmission at a chemical synapse. 1)Neurotransmitter binds with receptors associated with the postsynaptic membrane. 2)Calcium ions rush into neuron's cytoplasm. 3)An action potential depolarizes the membrane of the axon terminal. 4)The ligand-gated ion channels open. 5)The synaptic vesicles release neurotransmitter into the synaptic cleft. Which sequence of events is correct?

An inhibitory postsynaptic potential (IPSP)occurs in a membrane made more permeable to

Action potentials are normally carried in only one direction: from the axon hillock toward the axon terminals.If you experimentally depolarize the middle of the axon to threshold,using an electronic probe,then

Neurotransmitters are released from axon terminals via

When Na⁺ moves into a cell and K⁺ moves out of a cell,this activates which type of gated ion channel?

Action potentials move along axons

How could you increase the magnitude of the inhibitory postsynaptic potentials (IPSPs)generated at a synapse?

In a typical mammalian cell,if the [K⁺]ₒᵤtsᵢdₑ = 5mM and [K⁺]ᵢnsᵢdₑ = 140mM,what is the Nernst potential?

The membrane potential that exactly offsets an ion's concentration gradient is called the

The equilibrium potential is a function of which of the following?

Tetrodotoxin blocks voltage-gated sodium channels and ouabain blocks sodium-potassium pumps.If you added both tetrodotoxin and ouabain to a solution containing neural tissue,what responses would you expect?

Motor neurons release the neurotransmitter acetylcholine (ACh)and acetylcholinesterase degrades ACh in the synapse.If a neurophysiologist applies onchidal (a naturally occurring acetylcholinesterase inhibitor produced by the mollusc Onchidella binneyi)to a synapse,what would you expect to happen?