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. -Which of the following is a direct result of depolarizing the presynaptic membrane of an axon terminal?

A neuropeptide that might function as a natural analgesic is

The activity of acetylcholine in a synapse is terminated by

A toxin that binds specifically to voltage-gated sodium channels in axons would be expected to

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?

Although the membrane of a "resting" neuron is highly permeable to potassium ions, its membrane potential does not exactly match the equilibrium potential for potassium because the neuronal membrane is also

The surface on a neuron that discharges the contents of synaptic vesicles is the

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

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. -A common feature of action potentials is that they

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

In response to a stimulus, Na⁺ and K⁺ channels open, allowing for depolarization. The channels respond independently, with

Immediately after an action potential passes along an axon, it is not possible to generate a second action potential; thus, we state that the membrane is briefly

Use the following information to answer the next few questions. Over the course of a year, you notice that you are more frequently losing your balance, are unable to keep your train of thought, and occasionally have double vision. After visiting several specialists, you are diagnosed with multiple sclerosis (MS), the hardening and ultimate loss of the myelin sheath which insulates axons. -Neurons and support cells in the CNS have a limited ability to repair themselves; however, those of the PNS have a higher capacity for reparation. To slow or inhibit the breakdown of the myelin sheath, which type of cell could remyelinate the neurons?

Ionotropic receptors are found at synapses operated via

In a simple synapse, neurotransmitter chemicals are released by

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. -Why are action potentials usually conducted in one direction?

Two fundamental concepts about the ion channels of a "resting" neuron are that the channels

Neurotransmitters are released from axon terminals via

The fastest possible conduction velocity of action potentials is observed in

Neural transmission across a mammalian synaptic gap is accomplished by