Nervous System Functions and Structure Quiz

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Questions and Answers

What is the primary role of autonomic functions within the nervous system?

Facilitating cognitive tasks like planning and thinking

Controlling voluntary muscle movements

Regulating sensory perception and movement

Managing involuntary processes such as heartbeat and digestion (correct)

Which type of neurone is commonly involved in transmitting sensory information?

Bipolar neurones

Pseudo-unipolar neurones (correct)

Anaxomic neurones

Multipolar neurones

Which part of the nervous system predominantly supports cognitive skills such as thinking and planning?

Somatic nervous system

Central nervous system (correct)

Autonomic nervous system

Peripheral nervous system

What is a characteristic feature of the structure of glial cells?

They provide support and protection for neurones Signup and view all the answers

What does the term 'mixed spinal nerves' refer to?

Spinal nerves that carry both afferent and efferent signals Signup and view all the answers

What primarily generates the resting membrane potential in neurons?

Passive ion flux and active transport of ions Signup and view all the answers

Which ion is found in higher concentration inside the neuron at rest?

Potassium (K+) Signup and view all the answers

What is the typical value of the resting membrane potential in neurons?

-70 mV Signup and view all the answers

What role do microglia play in the nervous system?

Immune response and phagocytosis Signup and view all the answers

What effect does the distribution of chloride ions have on resting membrane potential?

It stabilizes a net negative charge inside the neuron. Signup and view all the answers

What is the primary role of oligodendrocytes in the central nervous system?

Myelinating axons for electrical insulation Signup and view all the answers

Which type of neuron is primarily responsible for sensory input?

Ganglion cell Signup and view all the answers

What is the function of astrocytes in the nervous system?

Removing waste products and regulating ion balance Signup and view all the answers

Which glial cell is associated with the peripheral nervous system?

Satellite cell Signup and view all the answers

Which function does not belong to microglia in the nervous system?

Maintaining the blood-brain barrier Signup and view all the answers

What type of neuron does a mitral cell belong to?

Sensory neuron Signup and view all the answers

Which cell type is primarily involved in scar formation in the nervous system?

Astrocyte Signup and view all the answers

Which structure is not directly involved in information processing within the nervous system?

Astrocyte Signup and view all the answers

What is the primary benefit of myelination in axons?

It facilitates the rapid jumping of the action potential between nodes. Signup and view all the answers

Which factor is NOT likely to influence conduction velocity in axons?

Type of neurotransmitter released Signup and view all the answers

What initiates the release of neurotransmitters at the axon terminal?

The arrival of an action potential causing calcium channels to open. Signup and view all the answers

How do postsynaptic potentials (PSPs) influence the generation of new action potentials?

They must reach a certain threshold to trigger an action potential. Signup and view all the answers

What process describes the summation of postsynaptic potentials from multiple synapses?

Spatial summation Signup and view all the answers

Which neurotransmitter is NOT mentioned as an example in the content provided?

Histamine Signup and view all the answers

What happens to neurotransmitters after they diffuse across the synaptic cleft?

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

What is the role of calcium ions (Ca2+) at the axon terminal?

They facilitate the release of neurotransmitter vesicles. Signup and view all the answers

What is the primary role of the sodium/potassium pump in maintaining the resting membrane potential?

It creates a net positive charge in the extracellular environment by pumping Na+ ions out. Signup and view all the answers

Which event occurs first during the generation of an action potential?

A stimulus triggers an influx of Na+ ions. Signup and view all the answers

What characterizes the action potential as an 'all-or-nothing' response?

It either occurs fully or not at all, with no partial responses. Signup and view all the answers

What is the primary characteristic of spatial summation?

It is the addition of simultaneous stimuli from several conducting fibres. Signup and view all the answers

What effect does myelin have on the propagation of action potentials?

It increases the resistance across the membrane and prevents ion leakage. Signup and view all the answers

What is the resting membrane potential primarily characterized by?

An intracellular environment with a net negative charge. Signup and view all the answers

Which term describes the process of successive stimuli affecting one nerve?

Temporal summation Signup and view all the answers

Which component of the nervous system is primarily responsible for forming the Blood Brain Barrier?

Endothelial cells Signup and view all the answers

At which part of the neuron is an action potential initially generated?

The axon hillock where the membrane depolarizes. Signup and view all the answers

How does the voltage-gated Na+ channel contribute to action potential propagation?

By creating a regenerative current that maintains amplitude. Signup and view all the answers

What role do astrocytes play in the Blood Brain Barrier?

They contribute to the formation and maintenance of tight junctions. Signup and view all the answers

What is the significance of depolarization in the context of action potentials?

It leads to a rapid influx of Na+ ions, which reverses the membrane potential. Signup and view all the answers

During which phase is the resting membrane potential established?

Resting phase Signup and view all the answers

Which type of neuron structure includes both dendrites and an axon?

Multipolar neuron Signup and view all the answers

What is the primary function of neurotransmitters at the synapse?

They facilitate communication between neurons. Signup and view all the answers

What is the main purpose of myelin in the nervous system?

To insulate axons and speed up signal propagation. Signup and view all the answers

Study Notes

Nervous Tissue 1

Nervous tissue is responsible for functions like heartbeat, breathing, digestion, body temperature, planning, thinking, emotions and behaviours, sensation, and movement
Nervous tissue comprises nerve conduction, structure of nervous tissue, and glial cells, and neuron structure.

Neuronal Structure

A neuron is the functional unit of the nervous system.
Neurons are specialized cells designed to transmit electrical impulses.
Neurons share common structural features for sending and receiving information.
Parts of a neuron: Nucleus, Cell body (Soma), Dendrite, Axon, Axon Terminals.

Neurone Types

Multipolar: e.g., motor neurons
Pseudo-unipolar: e.g., sensory neurons
Bipolar: e.g., in retina or olfactory system
Anaxonic: with no distinct axon

Neurones Form & Function

Various examples of neuron types, including motor neurons (spinal cord), Purkinje cells (cerebellum), mitral cells (olfactory bulb) and pyramidal cells (cortex), are shown.
Their shapes and roles are described

Glial Cells

Glial cells are not directly involved with information processing but are essential for survival and function of the nervous system.
Greek for "glue"
Types of Glial Cells: CNS - Astrocyte, Oligodendrocyte, Microglia, Ependymal cell. PNS - Satellite cell, Schwann cell

Glial Cells Structure & Function

Diagram displays structure, location and function of these cells
Extracellular space, blood capillaries and cells (oligodendrocyte, astrocyte, ependymal cell, neuron, microglia)

Cells of the Nervous System Summary

Neurones: Electrical signaling
Astrocyte: Regulates extracellular microclimate, removing waste products, helps to control passage between blood & nervous tissue, scar formation
Oligodendrocyte: Myelination - insulation for the axon & preventing degradation, enhances conduction speed
Microglia: Immune response, phagocytosis
Ependymal cell: Producing Cerebral Spinal Fluid (CSF)
Satellite Cell: PNS support cells, similar to astrocytes in CNS
Schwann Cell: Myelination - insulation for axon & preventing degradation, enhances conduction speed

Neurones At Rest

At rest, the inside of the cell membrane has a negative charge (-70mV).
This is due to an unequal distribution of sodium (Na+), potassium (K+) and chloride (Cl-) ions.
Extracellular fluid has a net positive charge and intracellular cytoplasm has a net negative charge.
A membrane potential of minus 70mV

Generation of an Action Potential

A stimulus creates an influx of positively charged ions, changing the membrane voltage to positive (approximately +30/40mV) - depolarization.
Rapid influx of Na+ ions followed by efflux of K+ ions forms the action potential.
All or nothing principle: action potential either occurs or does not, and voltage is always the same magnitude.

Propagation

Action potential is initiated at the axon hillock and propagates along the axon.
Voltage-gated Na+ channels cause a regenerative current, maintaining action potential amplitude.

Propagation Velocity

Action potential speed varies between neurons (0.1 m/s to 100 m/s)
Myelin increases resistance of the membrane, preventing ion leakage.
Saltatory conduction is faster in myelinated axons, with action potentials jumping between Nodes of Ranvier.
Axon diameter and temperature also influence conduction velocity.

Synaptic Transmission

Action potential reaches axon terminal, calcium channels open, neurotransmitters released into the synaptic cleft
Neurotransmitter diffuses across cleft and binds to receptors on postsynaptic neuron.
Activation of receptors opens Na+ channels, causing a postsynaptic potential.
If threshold reached, AP generated in postsynaptic neuron.
Neurotransmitters reabsorbed

Summation

Individual stimuli might be insufficient to trigger an action potential, but their sum can exceed the threshold.
Spatial summation: simultaneous stimuli from multiple synapses sum together to reach the threshold.
Temporal Summation: multiple stimuli in rapid succession sum together to reach the threshold.

Blood Brain Barrier

The BBB is a protective barrier between the blood and the brain.
Epithelial cells, proteins and astrocytes form the BBB, selectively controlling what passes.

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Description

Test your knowledge on the autonomic functions and the roles of various types of neurons and glial cells within the nervous system. This quiz covers essential concepts related to brain structure, sensory information transmission, and resting membrane potential. Perfect for students studying neuroscience or biology.