Exam 4: Principles of Neural and Hormonal Communication

What might happen on a postsynaptic neuron if, at the same time, it receives one stimulus at an excitatory synapse located close to the axon hillock but receives two stimuli at two different inhibitory synapses, both of which are far away from the axon hillock?

The refractory period limits the frequency of action potentials.

Indicate which characteristic applies to classical neurotransmitters and neuropeptides. a.neurotransmitters b.neuropeptides c.both neurotransmitters and neuropeptides d.neither neurotransmitters nor neuropeptides -Released from axon terminal

A postsynaptic neuron can either excite or inhibit a presynaptic neuron.

Sequence the following events correctly. 1. Neuratransmitter diffuses acrass cleft. 2. Calcium inchuces exdcytusis of neuratransmitter 3. Permeability of postsyneptic membrane altered 4. Ian chanels apen. 5. Neuratransmitter binds to receptor.

Indicate which characteristic applies to classical neurotransmitters and neuropeptides. a.neurotransmitters b.neuropeptides c.both neurotransmitters and neuropeptides d.neither neurotransmitters nor neuropeptides -Small: one amino acid or similar chemical

____________________ is a second messenger formed when a membrane enzyme called a cyclase becomes activated by a G protein.

What are four ways in which drugs might influence the nervous system at the neuronal level?

Divergence refers to the neuronal arrangement wherein the dendrites diverge to synapse with as many presynaptic inputs as possible.

Use these figures to answer the corresponding questions. -Which number identifies the structure that is primarily responsible for the absolute refractory period during an action potential? a.1 b.2 c.3 d.4 e.None of the above

Binding of an excitatory neurotransmitter to a postsynaptic neuron causes

____________________ are chemical messengers that do not cause the formation of EPSPs or IPSPs but rather bring about long-term changes that depress or enhance the action of the synapse.

The normal direction for the movement of an action potential along part of a neuron is from

The myelin on a myelinated fiber in the peripheral nervous system is part of Schwann cells wrapped around the axon.

Use this figure to answer the corresponding questions. -This figure shows a.the mechanism by which some lipid-soluble hormones affect their target cells b.the way insulin affects certain cells c.the method in which IP3 forms d.a common second messenger system for hormone that is derived from cholesterol e.none of these

The process by which incoming signals are conveyed into a target cell, where they are transformed into a certain cellular response is called signal _________.

Permeability of which ion is affected by a positive feedback mechanism once threshold is reached?

A spike is another name for the axon of a neuron.

Use the answer code below to answer this section. a.increased PNa+ and no change in PK+ b.decreased PNa+ and decreased PK+ c.increased PK+ and no change in PNa+ d.increased PK+ and increased PNa+ e.increased PK+ and decreased PNa+ f.Na influx g.Na+ efflux h.K+ influx i.K+ efflux -Ion movement that would cause an EPSP

If neuron Y's neurotransmitter is causing neuron X's membrane potential to decrease, then we would logically conclude that this neurotransmitter causes