oxins from poison dart-frogs, the former had no effect on a neurons resting potential but completely stopped its action potenti

The giant squid axon has a diameter = 1mm and 1 = 13mm. Compared to a mammalian neuron with a diameter = 1 um and ^ = 0.2mm, which of the following is correct? graded potentials can generate action potentials in the mammalian axon but not in the squid axon. graded potential of similar magnitude would result in action potentials with larger amplitude in the mammalian axon graded potentials of similar magnitude would result in action potentials with larger amplitude in the squid axon graded potentials of similar magnitude would travel furthest from their point of origin in the mammalian axon graded potentials of similar magnitude would travel furthest from their point of origin in the squid axon

If an excitatory synapse and inhibitory synapse generate postsynaptic potentials on the same neuron what can happen? a. The generated potentials will sum up to make a larger postsynaptic potential. b. Nothing will happen, because inhibitory neurons will not form synapses on the same neurons as excitatory neurons. c. The postsynaptic potential generated by the inhibitory synapse will shunt the excitatory synapse, leading to a reduction in the postsynaptic potential. d. None of the above

Use this illustration to place these events in the order they occur during synaptic communication: Column A Column B a. Voltage gated sodium channels carry the action potential to the synapse by allowing the influx of sodium ions. 1. 1 2 b. An increase in calcium levels triggers vesicle release. 3. 3 c. Sodium enters the post-synaptic cell, causing it to depolarize. 4. 4 d. Sodium influx at the synapse activates voltage gated 5. calcium channels which allow calcium ions to enter the presynaptic neuron. 6. 6. e. Neurotransmitters are released into the synaptic cleft. f. Ligand-gated ion channels are opened by the neurotransmitters. 2.

In the discussion section the authors wrote “In this study, we observed that different paradigms of tES application could ameliorate motor function impairments in ICH induced by collagenase administration into the striatum of rats.”  a. Is the information in this quote about afferent of efferent?             b.By what word or words do you know that your answer to the question is correct?            c. Why did you choose this word or words as an answer to the question?

The nerve impulses always travel in one direction from dendrites to axon terminals. What prevents an action potential from travelling backward? a. Hyperpolarization of the neuron makes the membrane more positive and prevents another action potential. b. After repolarization, the refractory period occurs, where the sodium ions are found outside the cell. c. After repolarization, the reversal of ions prevents another action potential as there would not be enough sodium ions outside the cell to rush in. d. The refractory period prevents another action potential by lowering the threshold potential.

How would antibodies against nicotinic acetylcholine receptors (nAChRs) affect the influx of sodium (Na+) into a skeletal muscle cell?  Group of answer choices These antibodies would target nAChRs for destruction leading to lower sodium influx in muscle cells. These antibodies would target nAChRs, changing their shape to allow calcium instead of sodium through. These antibodies would target nAChRs, changing their shape to allow only potassium through. These antibodies would target nAChRs aiding acetylcholine in its binding to receptors, leading to increased sodium influx in muscle cells.  pick one answer

Conduction velocity refers to the [a] at which an action potential travels along a neuron's axon. In invertebrates, conduction velocity can only be increased by [b]. However in vertebrates (exclusively), such as humans, conduction velocity can also be increased by [c]. This enables vertebrates to conserve [d] while still increasing conduction velocity. [a] [b] [c] [d] [Choose ] [Choose ] [Choose ] [Choose ]

Choose two false statements and explain why? Toxin causes voltage-gated sodium channels to open at a lower voltage toxin slows down the inactivation of sodium channels toxin causes ligand-gated sodium channels to open toxin causes voltage-gated potassium channels to open faster

Place the following events in chronological order from 1-8: Nat enters the cell, and depolarization occurs to approximately +30 mV. The voltage across the cell membrane is -70 mV, the resting membrane potential. Upon reaching the peak of the action potential, the VG Nat channels are inactivated by the closing of their inactivation gate and the activation gate of each VG K channel opens. VG K channels close by the closing of their activation gate, and the resting membrane potential is gradually restored. An excitatory post-synaptic potential depolarizes the membrane to threshold and the activation gate of VG Nat channels open. Upon returning to the resting membrane potential, VG Na channels are reset by opening of the inactivation gate and the closing of the activation gate. VG K+ channels are slow to close, resulting in an excess of K* efflux and hyperpolarization. Depolarization occurs as K+ flows out of the cell.