Neurophysiology Pt 2 Quiz

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Questions and Answers

What is the primary function of neuroglia cells?

To facilitate saltatory conduction in myelinated fibers

To regenerate damaged axons in the CNS

To provide support and maintenance functions for neurons (correct)

To process and transmit information

Which part of the neuron is responsible for receiving information?

Axon

Soma

Myelin sheath

Dendrites (correct)

What is the term for the degeneration of the axon distal to a lesion?

Wallerian degeneration (correct)

Myelin degeneration

Saltatory conduction

Neuroglial scar formation

What is the term for the jumping of action potentials from node to node down the axon?

Saltatory conduction Signup and view all the answers

What is the primary component of gray matter in the brain?

High population of soma Signup and view all the answers

Which glial cell type is responsible for forming the inner and outer glial limiting membranes of the CNS?

Astrocytes Signup and view all the answers

What type of neurons are most sensory (afferent) neurons?

Pseudo-unipolar Signup and view all the answers

What is the primary function of oligodendrocytes in the CNS?

Providing support to axons and neurons Signup and view all the answers

What is the function of Schwann cells in the PNS?

B and D Signup and view all the answers

What is the role of ependymal cells in the CNS?

Covering the brain ventricles and central canal of the CNS Signup and view all the answers

What is the primary function of sensory (afferent) neurons?

Sending information from receptors in sensory organs to the CNS Signup and view all the answers

What is the role of ependymal cells?

Involved in the creation of CSF Signup and view all the answers

What is the primary function of interneurons?

Connecting motor and sensory neurons together Signup and view all the answers

What is the term for the process of rapid depolarization in myelinated fibers?

Saltatory conduction Signup and view all the answers

What type of neurons are all motor (efferent) neurons?

Multipolar Signup and view all the answers

What is the primary function of motor (efferent) neurons?

Sending information to effector organs from the CNS Signup and view all the answers

What is the function of astrocyte ion channels and exchange ions with neighboring cells?

Controlling the concentration of important ions Signup and view all the answers

What is a characteristic of glial cells?

They lack axons and dendrites Signup and view all the answers

What is NOT a role of astrocytes in regards to providing structural and metabolic support to neurons?

Controlling level of neurotransmitters around the synapse Signup and view all the answers

What proportion of the glial cell population in the CNS is made up of astrocytes?

50% Signup and view all the answers

In which part of the nervous system are oligodendrocytes primarily found?

CNS Signup and view all the answers

What is the function of microglial cells in the CNS?

To act as macrophages and release NO Signup and view all the answers

What is the primary function of the myelin sheath?

To act as an electrical insulator and allow saltatory conduction Signup and view all the answers

What is the role of glial cells in the development of neurons?

Participating in myelin sheath production and modulating growth and development of damaged neurons Signup and view all the answers

What type of neuron has 1 axon and 1 dendrite, ultimately containing 2 processes?

Bipolar Signup and view all the answers

What is the primary function of the presynaptic terminal?

To transmit information Signup and view all the answers

What is the characteristic feature of multipolar neurons?

Having one axon and multiple dendrites Signup and view all the answers

What is the term for the origin of the axon and action potential?

Axon hillock Signup and view all the answers

What is NOT a role of astrocytes in regards to maintaining the working environment of neurons?

Participating in repair processes following tissue injuries Signup and view all the answers

What is the term for the gaps present within the myelin sheath?

Nodes of Ranvier Signup and view all the answers

What is the relationship between conduction velocity and axon diameter in unmyelinated fibers?

Conduction velocity is directly proportional to axon diameter in squared feet Signup and view all the answers

Which type of glial cell is found in the PNS?

Schwann cells Signup and view all the answers

Which type of glial cell aids in brain development by helping to destroy unnecessary synapses?

Microglial cells Signup and view all the answers

Study Notes

Glial Cells

Glial cells lack axons and dendrites, making them smaller than neurons.
Glial cells fill spaces in the nervous system not occupied by neurons or blood vessels.
Glial cells can divide and are more numerous than neurons in nervous tissue.
Glial cells do not produce action potentials and do not participate directly in synaptic interactions and electrical signaling.

Types of Glial Cells

Microglial Cells
- Act as macrophages, releasing NO to prevent viral replication.
- Participate in phagocytosis to clear debris.
- Protect the brain against injury and infection.
- Aid brain development by helping to destroy unnecessary synapses.
Astrocytes
- Star-shaped cells with numerous long processes.
- Make up 50% of the glial cell population within the CNS.
- Provide structural and metabolic support to neurons.
- Maintain neurons' working environment by controlling neurotransmitter levels and ion concentrations.
Oligodendrocytes
- Provide support to axons and neurons in the CNS.
- Extend processes to form myelin around adjacent axons.
Ependymal Cells
- Cover brain ventricles, central canal of the CNS, and the choroid plexus in the 4th ventricle of the medulla oblongata.
- Involved in creating CSF (cerebrospinal fluid).
Schwann Cells (Neurolemmocytes)
- Found in the PNS.
- Form myelin sheath around axons, with each cell forming internodes of the myelin sheath.

Neurons

Neurons are specialized in processing information.
Neurons are the major functional unit of the nervous system.
Neurons do not divide once they reach maturity, so any injury leading to neuronal death will permanently change the structure and function of the affected area.
Neurons communicate via synapses.

Structure of Neurons

Dendrites
- Receive information from other neurons.
- An information-receiving area of the cell membrane.
Soma (Cell Body or Perikaryon)
- Contains organelles.
Axon
- An information-carrying extension of the cell membrane.
- Action potentials travel down the axon at a speed of 0.5-120 meters per second.
Axon Hillock (Trigger Zone)
- Where the axon originates, and action potentials originate.
Presynaptic Terminal
- Located at the end of the axon, used for information transmission.
Myelin Sheath
- A modified plasma membrane wrapped around the axon in a spiral fashion.
- Enhances the speed of information transmission by acting as an electrical insulator and allowing saltatory conduction of impulses.

Classification of Neurons

Multipolar
- Have 1 axon and many dendrites.
- The most common structure type.
Bipolar
- Have 1 axon and 1 dendrite.
Pseudo-unipolar (Unipolar)
- Have 1 single stem process that bifurcates to form 2 processes, where 1 process goes to the CNS and the other process goes to the PNS.

Function of Neurons

Sensory (Afferent) Neuron
- Send information from sensory organs towards the CNS.
- Most sensory neurons are pseudo-unipolar.
Motor (Efferent) Neuron
- Send information to effector organs (muscles and glands) from the CNS.
- All motor neurons are multipolar neurons.
Interneuron (Association Neuron)
- Connect motor and sensory neurons together.
- Found in the CNS, usually multipolar or bipolar neurons.

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Description

This quiz covers the different types of glial cells found in the Central Nervous System (CNS) and Peripheral Nervous System (PNS), as well as their functions, including myelin production and modulating growth and development of damaged neurons.