Nervous System Overview Quiz

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Questions and Answers

What is the primary function of the neurons in the nervous system?

To protect neurons from damage

To coordinate the actions of muscles and glands

To produce hormones for communication

To transmit electrical signals for communication (correct)

Which of the following correctly describes the role of the nervous system in maintaining homeostasis?

It integrates information through slow chemical signaling

It uses hormones to manage body functions

It functions independently of other organ systems

It responds quickly to changes in the body and environment (correct)

What two main divisions make up the nervous system?

Cortical and Subcortical systems

Central and Peripheral Nervous Systems (correct)

Cerebral and Sensory systems

Autonomic and Somatic systems

Which of the following best describes the role of the neuroglia in the nervous system?

Protect and support neurons within the system Signup and view all the answers

How does the nervous system respond to detected changes in the body or environment?

By transmitting electrical impulses to muscles and glands Signup and view all the answers

Which type of glial cell is responsible for forming myelin in the central nervous system?

Oligodendrocytes Signup and view all the answers

What is a primary function of astrocytes in relation to blood vessels in the brain?

They contribute to the formation of a semi-permeable membrane that supports neurons. Signup and view all the answers

Which type of neuron is specifically responsible for transmitting information about stimuli to the central nervous system?

Sensory afferent neurons Signup and view all the answers

Why are gliomas particularly difficult to treat effectively?

They are highly malignant and grow rapidly, often requiring surgery. Signup and view all the answers

Which class of neurons is solely found within the central nervous system and allows for processing information?

Interneurons Signup and view all the answers

Which of the following accurately describes the nerve root functions in relation to the spinal cord?

The dorsal nerve root is responsible for carrying sensory information into the spinal cord. Signup and view all the answers

What is the primary function of the cauda equina within the spinal cord structure?

It consists of nerve roots that extend from the end of the spinal cord. Signup and view all the answers

Which statement about the composition of the spinal cord is correct?

The abundance of myelin in white matter contributes to its white appearance. Signup and view all the answers

Which layer of the meninges is the innermost protective layer surrounding the spinal cord?

Pia mater Signup and view all the answers

Which regions of the spinal cord are accurately matched with their innervation areas?

Sacral region: legs, feet, and genital regions. Signup and view all the answers

What is the primary function of the axon in a neuron?

To carry nerve signals away from the cell body Signup and view all the answers

What role do Schwann cells play in the nervous system?

They create the myelin sheath in the peripheral nervous system. Signup and view all the answers

Which of the following statements accurately describes unmyelinated nerve fibers?

They perform functions where speed is not crucial. Signup and view all the answers

How do the Nodes of Ranvier contribute to nerve impulse conduction?

They allow for saltatory conduction, speeding up impulse transmission. Signup and view all the answers

In which development stage does myelination begin in humans?

The 14th week of fetal development Signup and view all the answers

Study Notes

Nervous System

Works with other organ systems to maintain homeostasis.
Consists of the brain, spinal cord, and nerves.
Receives and processes information about internal and external changes.

Overview of the Nervous System

Two systems coordinate body functions: Endocrine and Nervous.
Endocrine system: Utilizes hormones, chemical messengers, for communication.
Nervous system: Uses electrical signals for rapid communication.
3 Roles:
- Sensing: Detects changes using sense organs and nerve endings.
- Integrating: Processes information, relates it to past experiences, and determines appropriate responses.
- Responding: Directs muscles and glands to initiate changes based on processed information.

Nervous System Divisions

Central Nervous System (CNS): Consists of the brain and spinal cord.
Peripheral Nervous System (PNS): Network of nerves throughout the body.

Cells of the Nervous System

Neurons: Excitable cells responsible for nervous system communication.
Neuroglia: Supportive cells of the nervous system, also called glial cells.

Types of Glial Cells

Oligodendrocytes: Create myelin sheath in the brain and spinal cord, speeding up signal conduction.
Schwann cells: Form myelin sheath around nerves in the PNS, also form neurilemma.

Blood Brain Barrier (BBB)

Formed by astrocytes and endothelial cells lining capillaries.
Semi-permeable, allowing small molecules but blocking larger ones.
Protects the brain from foreign substances.
Makes treating brain disorders challenging due to limited medication access.

Brain Tumors

Most adult brain tumors are gliomas, derived from glial cells.
Gliomas are highly malignant and grow rapidly.
BBB hinders medication effectiveness, leading to reliance on surgery and radiation therapy.

Neurons

Nerve cells that communicate throughout the nervous system.
Three classes of neurons:
- Sensory (Afferent) Neurons: Detect stimuli and transmit information to the CNS.
- Interneurons: Found only in the CNS, connect sensory and motor pathways, process, store, and transmit information.
- Motor (Efferent) Neurons: Relay messages from the brain to muscles or glands.

Neuron Structure

Three basic parts:
- Cell body (Soma): Contains the nucleus, the neuron’s control center.
- Dendrites: Branch-like extensions that receive signals from other neurons.
- Axon: Single, long extension that carries signals away from the cell body.
- Myelin Sheath: Lipid-rich insulation around the axon, speeding up signal conduction.
  - Formed by Schwann cells in the PNS and oligodendrocytes in the CNS.
- Nodes of Ranvier: Gaps in the myelin sheath where signal conduction occurs.
- Synaptic knobs: Terminal branches of the axon responsible for signal transmission.

Myelin

Myelination enhances nerve signal conduction speed.
Unmyelinated fibers conduct signals more slowly, typically handling functions where speed isn’t crucial.
Myelination is not complete until late adolescence.

Multiple Sclerosis

Myelin sheaths surrounding CNS nerves deteriorate, replaced by scar tissue (plaques).
Symptoms: Visual disturbances, weakness, loss of coordination, and speech disturbances.

Synapses

Areas where nerve impulses transfer between neurons, facilitating communication.

Spinal Cord and Somatic Reflexes

Relays messages between the brain and the body.
31 pairs of spinal nerves exit the spinal cord.

Spinal Cord Overview

Bundle of nerve fibers extending from the brain stem to the first lumbar vertebra.
Cauda equina: Bundle of nerve roots at the end of the spinal cord, resembling a horse's tail.
Spinal nerves innervate different body regions:
- Cervical: Chest, head, neck, shoulders, arms, and diaphragm.
- Thoracic: Intercostal muscles, abdominal muscles, and back muscles.
- Lumbar: Lower abdominal wall, thighs, and legs.
- Sacral: Thighs, buttocks, legs, feet, and anal/genital regions.

Spinal Cord Structure

Located within a protective bony tunnel created by the vertebrae.
Composed of two types of nervous tissue:
- Gray matter: Non-myelinated, appears gray.
- White matter: Myelinated, appears white.
Epidural space: Space between the spinal cord’s outer covering and the vertebrae.

Spinal Nerve Attachments

Spinal nerves connect to the spinal cord via two roots:
- Dorsal (Posterior) Root: Contains fibers carrying sensory information to the spinal cord.
- Ventral (Anterior) Root: Carries motor information out from the spinal cord.

Meninges of the Spinal Cord

Three layers of connective tissue protecting the spinal cord:
- Pia mater: Innermost layer.
- Arachnoid mater: Middle layer.
- Dura mater: Outermost layer.

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Description

Test your knowledge on the structure and function of the nervous system. Explore the roles, divisions, and cells that make up this vital organ system. This quiz covers key concepts needed to understand how the nervous system interacts with other systems to maintain homeostasis.