Neuron and Reflex Arc Overview

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Questions and Answers

Match the types of degeneration with their descriptions:

Wallerian degeneration = Breakdown of the axon after injury leading to cell death Retrograde degeneration = Breakdown of the axon still attached to the cell body Chromatolysis = Loss of Nissl substances in the neuron Transsynaptic degeneration = Death of connected neurons due to synaptic relationships

Match the types of cells with their functions:

Ependymal cells = Secretion of cerebrospinal fluid (CSF) Schwann cells = Support axons and produce myelin sheaths Neurons in PNS = Ability to repair and regenerate after degeneration Neurons in CNS = Inability to reverse degeneration effects

Match the terms with their definitions:

Axon = Long projection that conducts electrical impulses away from the neuron's cell body Nissl substances = Ribosomal RNA involved in protein synthesis in the cell body Cerebrospinal fluid (CSF) = Fluid that surrounds and protects the brain and spinal cord Myelin sheath = Insulating layer that accelerates electrical signal transmission

Match the following processes with their outcome:

Wallerian degeneration = Detachment of the axon leading to cell death Retrograde degeneration = Breakdown of axon leading to cell body involvement Chromatolysis = Loss of the neuron’s ability to sustain itself Transsynaptic degeneration = Loss of nearby neurons linked through synapses Signup and view all the answers

Match the following types of neurodegeneration with their location:

PNS degeneration = Can often repair and regenerate CNS degeneration = Generally unable to reverse degeneration Ependymal cell function = Enabling CSF secretion Schwann cell function = Myelination of peripheral nerves Signup and view all the answers

Match the parts of a neuron with their functions:

Soma = Contains the nucleus and essential cellular machinery Dendrites = Receives messages from other neurons Axon = Carries information from the cell body Terminal Buttons = Transmits messages to another neuron Signup and view all the answers

Match the types of neurons according to their structure:

Multipolar Neuron = Most common type found in the CNS Bipolar Neuron = One axon and one dendritic tree at opposite ends Unipolar Neuron = Only one stalk that divides into two branches Pseudo-unipolar Neuron = Sensory neurons with one axon and dendrite Signup and view all the answers

Match the functional classification of neurons:

Afferent neurons = Transmits impulses to the spinal cord or brain Efferent neurons = Transmits impulses away from the brain Interneurons = Conducts impulses between other neurons Sensory neurons = Receives sensory signals from sensory organs Signup and view all the answers

Match the supporting cells in the nervous system with their functions:

Astroglia = Provides physical support to neurons Microglia = Engulfs dead neurons as phagocytes Oligodendroglia = Produces myelin sheaths for axons Ependymal Cells = Monitors the composition of cerebrospinal fluid Signup and view all the answers

Match the definitions with the parts of the neuron:

Synapse = Junction between a terminal button and a dendrite Reflex Arc = Impulse conduction route to and from the CNS Neural Transmission = Process of transmitting messages between neurons Neuron = Information-processing and transmitting element of the nervous system Signup and view all the answers

Match the terms related to neuron functions with their descriptions:

Efferent = Carries commands from the CNS to muscles Afferent = Brings sensory information to the CNS Interneurons = Connects other neurons within the CNS Reflex = Automatic response pathway involving the spinal cord Signup and view all the answers

Match the types of neurons with their roles:

Motor neurons = Conduct commands from CNS to muscles Sensory neurons = Receive signals from sensory organs Interneurons = Integrate information within the CNS Afferent neurons = Transmit sensory impulses toward the CNS Signup and view all the answers

Match the key neuron structures with their characteristics:

Dendrites = Tree-like extensions receiving signals Axon = Slender tube carrying information Terminal Buttons = Knobs at the end of axon branches Soma = Contains the nucleus and metabolic machinery Signup and view all the answers

Match the types of glial cells with their primary function:

Astrocytes = Support and nourish neurons Oligodendrocytes = Insulate axons with myelin Microglia = Clean up debris from dead neurons Ependymal Cells = Regulate cerebrospinal fluid composition Signup and view all the answers

Match each neuron type with its description:

Multipolar Neuron = Has many dendrites and a single axon Bipolar Neuron = Has one axon and one dendrite Unipolar Neuron = Single stalk that branches into two Pseudo-unipolar Neuron = Has a long single process with axonal function Signup and view all the answers

Match the following neuronal functions with their types:

Sensory Input = Performed by Afferent neurons Motor Output = Performed by Efferent neurons Integration = Performed by Interneurons Reflex Action = Involves a simple reflex arc Signup and view all the answers

Match the neuron types with their common locations:

Multipolar Neurons = Commonly found in the CNS Bipolar Neurons = Found in special sensory areas Unipolar Neurons = Typically located in sensory pathways Interneurons = Primarily in the brain and spinal cord Signup and view all the answers

Match the following neuron types according to their function:

Motor Neuron = Sends signals to muscles Sensory Neuron = Receives sensory information Interneuron = Connects sensory and motor neurons Pseudo-unipolar = Processes sensory information quickly Signup and view all the answers

Match glial cells with their roles in the CNS:

Astrocytes = Buffer and support neurons Microglia = Engulf pathogens and debris Oligodendrocytes = Form myelin sheaths Ependymal Cells = Help regulate cerebrospinal fluid Signup and view all the answers

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Study Notes

Neuron

The neuron is the fundamental unit of the nervous system, responsible for processing and transmitting information.
It consists of a soma (cell body), dendrites, an axon, and terminal buttons.
The soma contains the nucleus and vital machinery for the neuron’s life processes.
Dendrites receive neural messages from other neurons, resembling a tree-like structure.
The axon is a long, slender tube that carries information from the soma to the terminal buttons.
Terminal buttons are located at the ends of branches extending from the axon, responsible for transmitting messages to other neurons.
The junction between a terminal button and a dendrite or soma is known as a synapse, where neural transmission occurs.

Reflex Arc

A reflex arc is the pathway for nerve impulse conduction to and from the central nervous system (CNS), consisting of the brain and spinal cord.

Neuron Types (Structure)

Multipolar Neuron: The most common type in the CNS, characterized by one axon and multiple dendrites.
Bipolar Neuron: Possesses one axon and one dendritic tree at opposite ends of the soma, often found in sensory neurons.
Unipolar Neuron: Has a single stalk extending from the soma that branches into two extensions, one functioning as a dendrite and the other as an axon. Also known as pseudo-unipolar neurons.

Neuron Types (Function)

Afferent (Sensory) Neurons: Transmit nerve impulses towards the spinal cord or brain.
Efferent (Motor) Neurons: Transmit impulses away from the brain or spinal cord towards muscles or glands.
Interneurons: Connect various neurons within the brain or spinal cord, facilitating communication between afferent and efferent neurons.

Supporting Cells (Glia)

Astrocytes (Star Cells): Provide structural support to neurons, clear debris in the brain, chemically buffer fluid surrounding neurons, and supply nutrients and dispose of waste products.
Microglia: Smaller glia cells that act as phagocytes, engulfing dead neurons.
Oligodendroglia: Provide support to axons and produce myelin sheaths in the CNS.
Ependymal Cells: Epithelial cells that monitor cerebrospinal fluid (CSF) composition, with specialized cells participating in CSF secretion.
Schwann Cells: Support axons and produce myelin sheaths in the peripheral nervous system (PNS).

Degeneration

Wallerian Degeneration: Occurs when an axon is injured, causing the severed section to die due to lack of sustenance.
Retrograde Degeneration: The breakdown of the axon portion still attached to the cell body.
Chromatolysis: The cell body loses its Nissl substances and eventually loses its ability to sustain itself.

Degenerative Responses

Neurons in the PNS can sometimes reverse the effects of degeneration, repairing their structure and growing a new axon.
Neurons in the CNS are generally unable to reverse the degenerative process.
Transsynaptic Degeneration: Neurons that form synapses with dying neurons may also die as a consequence.