Neuroscience Exam 3 Flashcards

Questions and Answers

What neurotransmitter is classified as a monoamine?

Norepinephrine

If a resting potential becomes more negative, the membrane is?

hyperpolarized

What are muscles and glands whose activities are controlled by nervous activity called?

Effectors

The most rapid conduction of an impulse along an axon occurs on a fiber that is?

thick and myelinated Signup and view all the answers

A neuron may have?

one axon and many dendrites Signup and view all the answers

What two cell types occur in neural tissue?

Neuroglial & Neurons Signup and view all the answers

A nerve cell membrane becomes depolarized as a result of?

Na+ ion channels being opened and Na+ ions diffusing into the cell Signup and view all the answers

An immune response that affects the myelin coating on axons throughout the spinal cord and brain, triggering inflammation and leaving scars, is?

multiple sclerosis Signup and view all the answers

What type of electrical signal is an all-or-none response?

Action potential Signup and view all the answers

Presynaptic neurons release neurotransmitters by _________.

exocytosis Signup and view all the answers

In the central nervous system, myelin is formed by cells called?

oligodendrocytes Signup and view all the answers

At a synapse, match the types of neurons:

Presynaptic neuron = Neuron that releases the neurotransmitter Postsynaptic neuron = Neuron that responds to the neurotransmitter Signup and view all the answers

In a resting neuron, the area just inside of the cell membrane is more __________ than the area just outside of the cell membrane.

negative Signup and view all the answers

The myelin sheath along an axon is not continuous. What are the gaps between Schwann cells called?

Nodes of Ranvier Signup and view all the answers

Opiate drugs derived from poppies relieve pain in humans because the human nervous system has?

receptors for endogenous opiates Signup and view all the answers

Diverging axons amplify an impulse by?

contacting many neurons Signup and view all the answers

In what type of axon does saltatory conduction occur?

Myelinated Signup and view all the answers

The class of neurotransmitters called neuropeptides include which neurotransmitter(s)?

Enkephalins and substance P Signup and view all the answers

A neuron is stimulated, which changes membrane potential to the point where voltage-gated Na+ channels open and begin depolarizing the cell. The neuron has reached?

threshold Signup and view all the answers

In convergence, two or more incoming fibers contact a single neuron, whereas in divergence, impulses leaving a neuron pass into several output fibers.

True Signup and view all the answers

A drug that functions as an agonist?

activates a receptor, helping a neurotransmitter bind or triggering an action potential in some other way Signup and view all the answers

What is the effect of the binding of neurotransmitters to their receptors on the postsynaptic cell membrane?

Neurotransmitters are sometimes excitatory and sometimes inhibitory Signup and view all the answers

The brain and spinal cord comprise the central nervous system.

True Signup and view all the answers

Which cells produce myelin in the brain and spinal cord?

Oligodendrocytes Signup and view all the answers

The refractory period for an area of cell membrane occurs after?

an action potential occurs Signup and view all the answers

The neurotransmitter most likely produced when a person uses a drug that creates a sense of well-being is?

dopamine Signup and view all the answers

The neurotransmitter that controls skeletal muscle contraction is?

acetylcholine Signup and view all the answers

Neural stem cells can be harvested from autopsies and stored, alive, in banks, whereas neurons cannot, because?

neural stem cells have lower oxygen and energy requirements than neurons Signup and view all the answers

Neurotransmitters that are modified amino acids are?

dopamine Signup and view all the answers

Study Notes

Neurotransmitters and Synapses

Monoamines: Norepinephrine is classified as a monoamine neurotransmitter.
Neurotransmitter Release: Presynaptic neurons use exocytosis to release neurotransmitters into the synaptic cleft.
Neuropeptides: Enkephalins and substance P are examples of neuropeptide neurotransmitters.
Dopamine: Often increased when using drugs that induce a sense of well-being.

Neuron Structure and Function

Neuron Composition: Neurons have one axon and multiple dendrites to receive signals.
Membrane Potential: A resting neuron has a more negative internal environment compared to outside; becomes hyperpolarized if more negative.
Depolarization: Resulting from the opening of Na+ ion channels, causing Na+ ions to flow into the neuron.
Action Potentials: Represent an all-or-none electrical signal response.

Myelin and Conduction

Myelination: In the CNS, oligodendrocytes form myelin; Schwann cells create myelin in the PNS.
Saltatory Conduction: Occurs in myelinated axons, allowing for faster signal transmission.
Nodes of Ranvier: Gaps between myelinated segments are crucial for rapid conduction.

Neural Communication

Effectors: Muscles and glands that are controlled by nervous activity are termed effectors.
Refractory Periods:
- Absolute Refractory Period: No new action potential can be generated.
- Relative Refractory Period: A stronger-than-usual stimulus is required to trigger another action potential.

Immune Responses and Disorders

Multiple Sclerosis: An autoimmune condition affecting myelin, causing inflammation and scarring in the CNS.

Neural Pathways

Divergence and Convergence:
- Divergence amplifies impulses by connecting a neuron to multiple others.
- Convergence allows multiple signals to contact a single neuron.

Drug Interaction with Receptors

Agonists: Drugs that activate receptors facilitate neurotransmitter binding or can initiate an action potential.

Stem Cells and Neurons

Neural Stem Cells: Can be preserved posthumously due to lower oxygen needs compared to mature neurons, allowing for potential future therapies.

Summary of Key Neurotransmitters

Acetylcholine: Controls skeletal muscle contraction; essential for motor function.

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Description

Test your knowledge on key concepts in neuroscience with these flashcards. Cover topics such as neurotransmitters, membrane potentials, and effectors. Perfect for preparing for your Exam 3 in neuroscience!