A signal generated via a neurotransmitter in the synaptic cleft is considered an autocrine signal True False

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.

Inhibitory postsynaptic potentials cause what type of change at the post-synaptic membrane? Hyperpolarization Depolarization Decreased threshold No change

Correct answer: Ligand-gated ion channel don’t open until the neurotransmitter diffuses across the synapse and binds to the receptor, The calcium channels are blocked in the presynaptic cells, It takes time for the vesicular exocytosis to occur Please explain why each of the correct answer choices are correct. Thank you.

With respect to nerve impulses, the Rising Phase is initiated by binding of neurotransmitters to ligand channels. True False

A 67-year old man has been treated for prostate cancer. He is receiving a drug that blocks testosterone from binding to its intracellular receptor. Which of the following has this mechanism of action: Tamoxifen Flutamide Leuprolide Fulvestrant Interleukin-2

Action potentials are produced by voltage-gated channels True False

Nerve impulses are sent bidirectionally. True O False

Describe the 6 step sequence of events that occurs at the NMJ in response to a nerve Action Potential.

True/False - The action potential is always the same size, regardless of the strength of excitatory signaling that a neuron is receiving.