Neuroscience: Types of Neurons and Glial Cells

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Questions and Answers

What type of neuron has a single axon?

Bipolar neuron

Unipolar neuron (correct)

Multipolar neuron

Neuroglia

Which type of synapse involves direct communication between the axon of one neuron and the cell body of another?

Axoaxonic

Axosomatic (correct)

Axodendritic

Dendroaxonic

Which of the following is NOT a type of neuroglia in the CNS?

Astrocytes

Oligodendrocytes

Microglia

Schwann cells (correct)

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

Regulation of electrolyte balance Signup and view all the answers

What type of neuron features several dendrites and one axon?

Multipolar neuron Signup and view all the answers

Which type of synapse is characterized by a connection between the axon of one neuron and the dendrite of another?

Axodendritic Signup and view all the answers

Which of the following glial cells are responsible for forming the blood-brain barrier?

Astrocytes Signup and view all the answers

Which component is characteristic of bipolar neurons?

Single axon and single dendrite Signup and view all the answers

What is the primary function of the cell body (soma) in the nervous system?

Processes and interprets messages Signup and view all the answers

Which component of the central nervous system is primarily responsible for processing information?

Brain Signup and view all the answers

Which structure is responsible for transmitting messages away from the neuron?

Axon Signup and view all the answers

What is the mass of the nervous system approximately?

2 kg (4.5 lbs) Signup and view all the answers

Which part of the nervous system serves as the delivery network?

Peripheral nervous system Signup and view all the answers

What is the primary role of dendrites in a neuron?

Receive stimuli and transmit messages to the cell body Signup and view all the answers

Which statement correctly describes axons?

They are covered by a membrane called the axolemma. Signup and view all the answers

What function does the axon terminal serve?

Transfers the impulse to another neuron or effector organ Signup and view all the answers

How many pairs of cervical nerves are present in the human body?

8 pairs Signup and view all the answers

What structure forms the crossbar of the H in the gray matter of the spinal cord?

Gray commissure Signup and view all the answers

What does the posterior median sulcus represent in relation to the spinal cord structure?

Narrow furrow on the posterior side Signup and view all the answers

Where is the central canal located within the spinal cord?

In the center of the gray commissure Signup and view all the answers

What is the cauda equina commonly referred to as?

Horse’s tail Signup and view all the answers

What is the primary function of sensory input in the nervous system?

To detect stimuli from the environment Signup and view all the answers

Which structure is responsible for processing the information received from sensory inputs?

Brain Signup and view all the answers

What does the output phase of the nervous system involve?

Eliciting a motor response by activating effectors Signup and view all the answers

How is sensory information transmitted to the brain and spinal cord?

Via cranial and spinal nerves Signup and view all the answers

What structure is located at the outer part of the spinal cord?

Gray matter Signup and view all the answers

Which statement about white matter in the spinal cord is true?

It contains myelinated axons Signup and view all the answers

What type of function does the integrative function in the nervous system primarily serve?

Analyzing and interpreting sensory information Signup and view all the answers

Which component is responsible for motor output in the nervous system?

Cranial and spinal nerves Signup and view all the answers

What is the primary function of the anterior gray horn in the spinal cord?

Contains somatic motor nuclei for skeletal muscle contraction Signup and view all the answers

Which of the following best describes the posterior gray horn?

Includes axons of incoming sensory neurons and interneurons Signup and view all the answers

What is the characteristic location of the lateral gray horn?

Located between the anterior and posterior gray horns Signup and view all the answers

Which of the following accurately describes 'nuclei' in the context of spinal cord anatomy?

Clusters of neuronal cell bodies Signup and view all the answers

What role does the anterior white commissure play in the spinal cord?

Connects the white matter of the right and left sides Signup and view all the answers

Study Notes

Types of Neurons

Unipolar: A single axon extending from the cell body.
Bipolar: Has one dendrite and one axon.
Multipolar: Several dendrites and one axon.

Neuroglia/Glial Cells

CNS:
- Astrocytes: Support structure, maintain metabolic environment, regulate electrolyte balance, form the blood-brain barrier (BBB), and repair damaged tissue.
- Oligodendrocytes: Form myelin sheaths around axons in the CNS.
- Microglia: Remove cellular debris and pathogens, act as immune cells in the CNS.
- Ependymal cells: Line the ventricles of the brain and central canal of the spinal cord, produce cerebrospinal fluid.
PNS:
- Schwann cells/Neurolemmocytes: Form myelin sheaths around axons in the PNS.
- Satellite cells: Surround neuron cell bodies in ganglia, provide support and regulate the microenvironment.

Synapses

Communication between neurons: The transfer of information from the axon terminal of one neuron to the receptive region of another neuron.
Types of Synapses:
- Axodendritic: Connection between the axon of one neuron and the dendrite of another.
- Axosomatic: Direct communication between the axon of one neuron and the cell body of another.
- Axoaxonic: Synapse made by one neuron onto the synapse of another neuron.

Organization of the Nervous System

Nervous System: Two main subdivisions:
- Central Nervous System (CNS): Processing center, including the brain and spinal cord.
- Peripheral Nervous System (PNS): Delivery network, connecting the CNS to the rest of the body.

Anatomy of a Neuron

Cell Body/Soma: Contains the organelles of a neuron, including the nucleus. Processes and interprets messages received and transmitted by the neuron. Found in gray matter.
Dendrites: Receive stimuli and transmit them toward the cell body.
Axon: Transmits messages away from the cell body, often longer than dendrites. Covered by a membrane called the axolemma.
Axon Terminal: Most distal end of the axon, transfers impulses to another neuron or effector organ.

Sensory, Integrative, and Motor Functions

Sensory Function: Detects stimuli and carries sensory information into the CNS through cranial and spinal nerves.
Integrative Function: Processes and analyzes sensory information.
Motor Function: Initiates motor responses to stimuli, activating effectors (muscles and glands) through cranial and spinal nerves, causing muscle contractions and gland secretions.

Cranial Nerves

12 pairs of cranial nerves, each with a specific function:
- Some carry sensory information, others carry motor commands, and some carry both.

Spinal Cord

External Anatomy:
- Rough oval shape, flattened anteriorly and posteriorly.
- 31 pairs of spinal nerves: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal.
- Cauda equina: Roots of lower spinal nerves extending inferiorly from the spinal cord.
Internal Anatomy:
- Anterior Median Fissure: Wide groove on the ventral side.
- Posterior Median Sulcus: Narrow furrow on the dorsal side.
- Gray Matter: Contains neuronal cell bodies, interneurons, and axons of sensory neurons. Forms the 'H-shaped' center of the spinal cord.
  - Gray Commissure: Connects the two sides of the gray matter.
  - Central Canal: Small space in the center of the gray commissure containing cerebrospinal fluid.
  - Anterior White Commissure: Connects the white matter of the right and left sides of the spinal cord.
- Nuclei: Clusters of neuronal cell bodies within the gray matter.
- Horns: Subdivided regions of gray matter on each side of the spinal cord:
  - Anterior Gray Horn: Contains somatic motor nuclei (cell bodies of motor neurons controlling skeletal muscle contractions).
  - Posterior Gray Horn: Contains axons of sensory neurons and interneurons.
  - Lateral Gray Horn: Present in the thoracic and upper lumbar segments, contains cell bodies of autonomic motor neurons.
White Matter: Outer part of the spinal cord, contains myelinated axons.

Spinal Nerves

Cervical Plexus: Innervates the neck, shoulders, and diaphragm.
Brachial Plexus: Innervates the arms, hands, and chest.
Lumbar Plexus: Innervates the lower back, abdomen, and legs.
Sacral Plexus: Innervates the pelvic region, buttocks, and legs.

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Description

This quiz covers the various types of neurons including unipolar, bipolar, and multipolar neurons, as well as detailed descriptions of glial cells in the central and peripheral nervous systems. Test your understanding of their functions and how they support neural communication. Perfect for students in neuroscience courses.