ANAT 262 Lecture Notes - Fluoxetine, Excitatory Synapse, Axon Terminal

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ceruleanprairie-dog589

21 May 2012

School

McGill University

Department

Anatomy & Cell Biology

Course

ANAT 262

Professor

John Presley

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Document Summary

Neurons are a special type of cell because they can use their electrical properties to produce signals, called action potentials, to transfer information to one another. Neurons communicate through joinings called synapses, through which the aps are sent from one neuron to another. Ion channels play a large role in the production and propagation of action potentials: remember, they only mediate passive transport. A neuron has 3 parts: a soma, the cell body, an axon and dendrites; the somatodendritic part is used to receive information while the axon is used to send information. Neurons process information in the form of electrical signals (nerve impulses or action potentials) that travel along their axons, usually to the somatodendritic portion of another neuron. Electrical charges move across the membrane in the form of charged ions. Their movement is selectively controlled by ion channels and ion pumps.

Related Questions

3. Which of the following is TRUE about a motor neuron?

		It passes information to another motor neuron.
		It passes information to another neuron.
		It stimulates cells associated with muscles or glands.
		It cannot generate an action potential.

2. Choose the immediate event that needs to occur for a nerve to fire an action potential.

		Voltage-gated potassium ion channels need to open.
		A threshold potential will need to be reached.
		Depolarization will need to be happen.
		Voltage-gated sodium ion channels need to close.

1. Choose the TRUE statement with respect to axons and/or dendrites.

		Dendrite is the location that a neurotransmitter moves into the synamptic cleft.
		Action potentials travel along the axon of a neuron.
		A neuron will typically have more axons than dendrites.
		More than one is correct

amaranthmouse537

Describe, in your own words, the process by which neuronscommunicate with one another electrochemically. Include a detaileddescription of how neurons receive information across the synapse,generate PSPs, and conduct action potentials

emeraldprairie-dog191

Santiago Ramon y Cajalâs theory of dynamic polarization refers to the:

(a)membrane potential of a neuron at rest.

(b)membrane potential of a neuron firing action potentials.

(c)opening and closing of gated channels in the membrane.

(d)one way flow of information in neurons from dendrites to axon terminals.

(e)one way flow of information in neurons from axon terminals to dendrites.

Over the course of scientific history, there are many examples of scientists reaching the right conclusion for the wrong reasons. When Schwann first proposed that the nervous system was made of individual cells, he based it on observations of:

(a)synapses.

(b)dendrites

(c)axon terminals.

(d)astrocytes.

(e)Nodes of Ranvier.

The synaptic cleft was finally seen in the 1950s. What prevented scientists from seeing it earlier?

(a)The resolution of the light microscope.

(b)They were looking in the wrong place.

(c)Their tissue was not appropriately stained.

(d)Myelination of the axons.

(e)all of the above

The resting membrane potential of a neuron is approximately:

(a) +65 V

(b) +65 mV

(d) -65 mV

What is largely responsible for the resting membrane potential in a neuron?

(a)Axonal insulation by myelin

(b)Voltage-Gated Sodium Channels

(c)The Action Potential

(d)Potassium Leak Channels

Which of the following would DECREASE the propagation velocity of an action potential down an axon?

(a)Increase in axon diameter

(b)Increase myelination between nodes of Ranvier

(c)Remove myelination between nodes of Ranvier

(d)Decrease density of voltage-gated Na+ channels except at the Nodes of Ranvier

The resting membrane potential of a neuron can be estimated using the:

(a)Nernst equation

(b)Goldman equation

(c)Hodgkin and Huxley equation

(d)Ohmâs law

18. What would happen to the resting membrane potential of a neuron if you added K+ to the extracellular fluid?

(a)Resting membrane potential would increase (become more positive)

(b)Resting membrane potential would decrease (become more negative)

(c)Resting membrane potential would not change

(d)Resting membrane potential would be abolished

. Which of the following statements is FALSE for Graded Potentials

(a)Magnitude changes with magnitude of triggering stimulus

(b)Magnitude decreases with distance from initial site

(c)Cannot be summed

(d)No refractory period

In the nervous system, the strength of the stimulus is coded into:

(a)The frequency of action potentials generated

(b)The amplitude of action potentials generated

(c)Both the frequency and amplitude of action potentials generated

(d)The duration of individual action potentials generated

Ion movement during both the depolarization and repolarization phases of an action potential are the result of:

(a)active transport pumps along the neuron membrane.

(b)diffusion of ions down their electrochemical concentration gradients.

(c)negative feedback loops.

(d)All of the above

At the peak of the action potential, the membrane potential is:

(a)Exactly at the Na+ equilibrium potential

(b)Greater (more positive) than the Na+ equilibrium potential

(c)Above 0 mV but less positive than the Na+ equilibrium potential

(d)0 mV

ANAT 262 Lecture Notes - Fluoxetine, Excitatory Synapse, Axon Terminal

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