Neuroscience Chapter 10 Flashcards

Questions and Answers

Distinguish between neurons and neuroglia.

Neurons are the structural and functional cells reacting to changes in their environment. Neuroglia are supporting cells necessary for nourishing and maintaining the neurons.

What are dendrites?

Branchlike parts of a neuron that are specialized to receive information.

What are chromatophilic substances (Nissl bodies)?

They correspond to rough endoplasmic reticulum in other cells.

What is an axon?

A threadlike extension of a neuron that carries nerve impulses away from the cell body. Signup and view all the answers

What is the cell body of a neuron?

The largest part of a typical neuron; contains the nucleus and much of the cytoplasm. Signup and view all the answers

What are neurofilaments?

Fine thread-like structures that form a matrix in the cytoplasm; they provide support for the cell membrane and maintain the shape of the neuron. Signup and view all the answers

What do Schwann cells and oligodendrocytes have in common?

Both are neuroglial cells. Signup and view all the answers

How do Schwann cells and oligodendrocytes differ?

Schwann cells are found in the PNS, while oligodendrocytes are part of the CNS. Signup and view all the answers

Distinguish between myelinated and unmyelinated axons.

Myelinated nerve fibers are wrapped in myelin sheaths formed by Schwann cells, making them appear white. Unmyelinated fibers lack these sheaths and appear gray. Signup and view all the answers

How may an injured neuron regenerate?

The distal portion deteriorates, and new sprouts develop from the proximal end, potentially rejoining with original connections. Signup and view all the answers

How is information passed from a presynaptic neuron to a postsynaptic neuron?

Nerve impulses pass at synapses where the presynaptic neuron stimulates or inhibits the postsynaptic neuron. Signup and view all the answers

What triggers the release of neurotransmitter at the synaptic knob?

Calcium ions. Signup and view all the answers

Explain the relationship between an action potential and impulse conduction down an axon.

An action potential occurs at a specific site and sends an electrical impulse in a wavelike manner down the axon. Signup and view all the answers

What is the importance of the nodes of Ranvier in nerve impulse conduction?

They enable saltatory conduction, where impulses jump from node to node, speeding up transmission. Signup and view all the answers

How do enzymes within the synaptic cleft prevent continuous stimulation of the postsynaptic cell?

Enzymes rapidly decompose transmitters to keep signal duration short. Signup and view all the answers

What are the general functions of the nervous system?

Sensory: gathers information. Integrative: processes and stores information. Motor: transmits commands to effectors. Signup and view all the answers

Describe structural and functional differences among neurons.

Multipolar: one axon, many dendrites; unipolar: one process that divides; bipolar: two processes. Signup and view all the answers

Identify the types of neuroglia in the CNS and their functions.

Astrocytes, oligodendrocytes, microglia, and ependymal cells each perform distinct supportive roles. Signup and view all the answers

What prevents a postsynaptic cell from being continuously stimulated?

Enzymes in the synaptic cleft decompose neurotransmitters rapidly. Signup and view all the answers

Study Notes

Neurons vs. Neuroglia

Neurons are the primary signaling cells in the nervous system, responding to changes in the environment.
Neuroglia serves as supporting cells, nurturing and maintaining neurons.

Dendrites

Dendrites are specialized, branchlike structures that receive information from other neurons.

Chromatophilic Substance

Known as Nissl bodies, they correspond to rough endoplasmic reticulum and are involved in protein synthesis.

Axon

An axon is a long, threadlike extension that carries nerve impulses away from the neuron's cell body.

Cell Body

The largest part of a neuron containing the nucleus and cytoplasm, crucial for cell function.

Neurofilaments

Fine structures within the neuron’s cytoplasm that provide structural support to the cell membrane.

Schwann Cells vs. Oligodendrocytes

Both are types of neuroglial cells; Schwann cells are in the peripheral nervous system (PNS), while oligodendrocytes are in the central nervous system (CNS).
Schwann cells form myelin sheaths around large axons, while oligodendrocytes produce myelin for multiple axons.

Myelinated vs. Unmyelinated Axons

Myelinated axons are wrapped in myelin sheaths formed by Schwann cells, appearing white.
Unmyelinated axons lack myelin sheaths and appear gray, with Schwann cells only forming grooves.

Neuron Regeneration

An injured neuron's distal portion deteriorates; macrophages clear debris.
The proximal axon develops sprouts guided by nerve growth factors, potentially reconnecting if they grow into the original matrix.

Synaptic Transmission

Nerve impulses are transmitted at synapses, where the presynaptic neuron stimulates or inhibits the postsynaptic neuron.

Calcium Ions in Neurotransmitter Release

The influx of calcium ions into the synaptic knob is essential for releasing neurotransmitters.

Action Potential and Impulse Conduction

An action potential sends an electrical impulse sequentially along the axon, maintaining its amplitude, resulting in nerve impulse propagation.

Nodes of Ranvier and Impulse Conduction

Myelinated fibers conduct impulses via saltatory conduction, jumping between nodes, while unmyelinated fibers conduct impulses more slowly across the entire surface.

Role of Enzymes in Synaptic Cleft

Enzymes in the synaptic cleft decompose neurotransmitters rapidly, preventing prolonged stimulation of postsynaptic cells.

General Functions of the Nervous System

Sensory: Detects changes in the environment.
Integrative: Combines sensory input for sensations and thought.
Motor: Communicates information from the CNS to effectors (muscles and glands).

Structural and Functional Differences Among Neurons

Multipolar: One axon and multiple dendrites; primarily in the CNS.
Unipolar: One process split into two branches for sensory information.
Bipolar: Two processes; one axon and one dendrite, found in certain sensory pathways.

Types of Neuroglia in the CNS

Astrocytes: Support neuron structure, regulate ion concentration, and respond to brain injury.
Oligodendrocytes: Form myelin in the CNS and can myelinate multiple axons.
Microglia: Mediate immune responses by phagocytizing debris and bacteria.
Ependymal cells: Line the central canal and ventricles, may have cilia for fluid movement.

Postsynaptic Cell Stimulation Prevention

Enzymatic action and neurotransmitter reuptake mechanisms ensure that stimulation of postsynaptic cells is brief and controlled.

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Test your knowledge with these flashcards focused on key terms from Chapter 10 of Neuroscience. Each card provides a definition to help you understand the differences between neurons and neuroglia, as well as other essential concepts. Perfect for revision or quick learning on this important subject.