Nervous System Overview

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Questions and Answers

What is the primary function of sensory neurons?

To convey commands to muscles, organs, and glands

To process information in the central nervous system

To receive information from the environment and transmit it to the central nervous system (correct)

To connect neurons within the central nervous system

Which type of neuron is primarily involved in processing information within the central nervous system?

Sensory neurons

Motor neurons

Bipolar neurons

Interneurons (correct)

Which classification of neurons is characterized by one primary projection that serves as both axon and dendrites?

Multipolar neurons

Bipolar neurons

Unipolar neurons (correct)

Motor neurons

What is the primary role of motor neurons in the nervous system?

To receive commands from other neurons and convey them to muscles and glands Signup and view all the answers

Which type of neuron has a cell body, a long axon, and short dendrites, and is most commonly associated with motor function?

Multipolar neurons Signup and view all the answers

What is the primary function of dendrites in a neuron?

To receive messages from other cells Signup and view all the answers

Which part of a neuron serves as the protective covering for the axon?

Myelin sheath Signup and view all the answers

What is the role of the nodes of Ranvier in neural transmission?

To facilitate rapid conduction of nerve impulses Signup and view all the answers

What is contained within the synaptic knobs at the tips of axon terminals?

Synaptic vesicles Signup and view all the answers

What defines a synapse in the context of neuronal communication?

The connection between neurons allowing message transfer Signup and view all the answers

What is the primary role of acetylcholine?

Controlling heartbeat and triggering muscle contractions Signup and view all the answers

Which neurotransmitter is primarily involved in the body's 'fight or flight' response?

Epinephrine (Adrenaline) Signup and view all the answers

What type of action does GABA have in the nervous system?

Inhibitory and calming Signup and view all the answers

Dopamine is classified as which type of neurotransmitter?

Both excitatory and inhibitory Signup and view all the answers

Which neurotransmitter is known as the body's natural pain reliever?

Endorphins Signup and view all the answers

Which statement about neurotransmitters is false?

All neurotransmitters are purely excitatory. Signup and view all the answers

What common effect do SSRIs (selective serotonin reuptake inhibitors) have?

Increase serotonin levels Signup and view all the answers

Which neurotransmitter is associated with learning and long-term memory?

Glutamate Signup and view all the answers

What is the primary role of neurotransmitters in the synaptic process?

They bind to membrane receptors on the postsynaptic cell. Signup and view all the answers

Which type of glial cell is primarily involved in producing myelin?

Oligodendrocytes Signup and view all the answers

What is the function of microglia in the nervous system?

They act as scavengers to remove dead cells. Signup and view all the answers

Which type of glial cell contributes to the formation of the blood-brain barrier?

Astrocytes Signup and view all the answers

What is reuptake in the context of neurotransmission?

The removal of neurotransmitters from receptor sites to prepare for new stimulation. Signup and view all the answers

Which glial cells are known to cover the cell bodies of neurons in the PNS ganglia?

Satellite glial cells Signup and view all the answers

What is a primary function of ependymal cells in the central nervous system?

To promote circulation of cerebrospinal fluid. Signup and view all the answers

Which cell type significantly increases the speed of action potentials down the axon?

Oligodendrocytes Signup and view all the answers

Study Notes

Divisions of the Nervous System

Comprised of the Central Nervous System (CNS) and Peripheral Nervous System (PNS).

Neurons

Fundamental units of the nervous system, responsible for transmitting information.
Classified into three main types: sensory neurons, motor neurons, and interneurons.

Sensory Neurons

Gather information from internal and external environments and relay it to the CNS for processing.

Motor Neurons

Convey commands from other neurons to muscles, organs, and glands.

Interneurons

Exclusive to the CNS, these neurons connect other neurons, facilitating information processing.

Unipolar Neurons

Characterized by a single projection serving both as axon and dendrites; mainly sensory neurons found in skin, muscles, and organs.

Bipolar Neurons

Possess an axon for signals to the brain and spinal cord, and dendrites for signals from organs; relatively rare and located in sensory systems (visual and auditory).

Multipolar Neurons

Featuring multiple dendrites and a long axon, these are primarily motor neurons and interneurons.

Functions of a Neuron

Receive, integrate, and communicate signals to target cells (other neurons, muscles, glands).

Parts of a Neuron

Dendrites: Receive messages from other cells.
Cell Body (Soma): Contains the nucleus, maintaining cell health.
Axon: Transmits messages to other cells.
Myelin Sheath: Insulation that speeds up neural signal transmission.
Nodes of Ranvier: Gaps in myelin facilitating rapid conduction of impulses.
Axon Terminals: Transmit electrical signals to the synapse.
Synaptic Knobs (Terminal Buttons): Contain synaptic vesicles with neurotransmitters.

Synapse

Connection between neurons, transmitting information from the presynaptic neuron to the postsynaptic neuron.

Types of Synaptic Connections

Neuromuscular Junctions: Connections between neurons and skeletal muscle cells.
Neuroeffector Junctions: Connections between neurons and smooth muscle or glands.

Neurotransmitters

Chemical messengers transmitting signals from nerve cells to target cells; categorized into excitatory and inhibitory.

Agonists and Antagonists

Agonists: Enhance neurotransmitter effects.
Antagonists: Block or diminish neurotransmitter activity.

Key Neurotransmitters

Acetylcholine: Triggers muscle contraction, influences hormone release and memory; excitatory.
Dopamine: Involved in memory, learning, and movement; has both excitatory and inhibitory effects.
Endorphins: Natural pain relievers that produce feelings of euphoria; inhibitory.
Epinephrine (Adrenaline): Prepares body for "fight or flight"; acts as both hormone and excitatory neurotransmitter.
GABA: Regulates mood with an inhibitory action; prevents over-excitation of neurons.
Serotonin: Influences mood, sleep, and appetite; inhibitory and linked to mental health.
Glutamate: Critical for learning and memory; excitatory but can cause overstimulation issues like migraines.

Action Potential

Neural impulse initiated by excitatory or inhibitory signals; travels down the axon triggering neurotransmitter release.

Reuptake

Process where neurotransmitters exit receptor sites to allow for subsequent stimulation; involves recycling back into synaptic vesicles.

Glial Cells

Support and protect neurons; more abundant than neurons; provide nutrients, myelinate axons, and remove waste.

Types of Glial Cells

Astrocytes: Regulate blood flow, maintain fluid composition around neurons, and contribute to the blood-brain barrier.
Microglia: Act as scavengers, cleaning up dead cells and debris.
Oligodendrocytes: Produce myelin for axon insulation to enhance action potential speed.
Schwann Cells: Similar function to oligodendrocytes in the PNS.
Satellite Glial Cells: Support neuron function and act as a protective barrier in PNS ganglia.
Ependymal Cells: Line ventricles of the brain and spinal canal, facilitating cerebrospinal fluid circulation.

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Description

Explore the essential components of the nervous system, including the Central Nervous System (CNS) and Peripheral Nervous System (PNS). This quiz covers the types of neurons, their functions, and how they contribute to the processing of information in the body.