Anatomy & Physiology: Nervous System Study Guide

Study Guide - Smart Notes

Tailored notes based on your materials, expanded with key definitions, examples, and context.

Q1. What are the three main functions of the nervous system? Be able to recognize examples of each.

Background

Topic: Functions of the Nervous System

This question tests your understanding of the basic roles the nervous system plays in the body and your ability to identify real-life examples of each function.

Key Terms:

Sensory Input: Gathering information from sensory receptors.
Integration: Processing and interpreting sensory input.
Motor Output: Responding by activating effector organs (muscles or glands).

Step-by-Step Guidance

List the three main functions of the nervous system.
For each function, think of a specific example (e.g., touching a hot stove for sensory input).
Describe how the nervous system processes the information (integration) and what response it triggers (motor output).
Review textbook or lecture examples to reinforce your understanding of each function.

Try solving on your own before revealing the answer!

Final Answer:

Sensory Input: The nervous system detects changes inside and outside the body (e.g., receptors in the skin sense temperature).
Integration: The nervous system processes and interprets sensory input (e.g., the brain realizes the stove is hot).
Motor Output: The nervous system activates effector organs to cause a response (e.g., muscles contract to pull your hand away).

Each function is essential for the body to sense, process, and respond to stimuli.

Q2. What are the principal parts of the nervous system and their functions/divisions?

Background

Topic: Organization of the Nervous System

This question tests your knowledge of the major anatomical and functional divisions of the nervous system.

Key Terms:

CNS (Central Nervous System): Brain and spinal cord.
PNS (Peripheral Nervous System): All neural tissue outside the CNS.
Divisions: Sensory (afferent), Motor (efferent), Somatic, Autonomic, Sympathetic, Parasympathetic.

Step-by-Step Guidance

Identify the two main anatomical divisions: CNS and PNS.
List the components of each division (e.g., what structures are in the CNS?).
Describe the main functions of the CNS and PNS.
Break down the PNS into its functional subdivisions (sensory/motor, somatic/autonomic, etc.).
Think about examples of each division's function.

Try solving on your own before revealing the answer!

Final Answer:

CNS: Consists of the brain and spinal cord; responsible for integration and command.
PNS: Consists of nerves and ganglia outside the CNS; divided into sensory (afferent) and motor (efferent) divisions.
Motor Division: Further divided into somatic (voluntary control of skeletal muscles) and autonomic (involuntary control of smooth muscle, cardiac muscle, and glands).
Autonomic Division: Subdivided into sympathetic (fight or flight) and parasympathetic (rest and digest) systems.

Each part has a specific role in processing and responding to information.

Q3. What are the types and functions of neuroglia in the CNS and PNS?

Background

Topic: Neuroglia (Glial Cells)

This question tests your ability to identify the different types of supporting cells in the nervous system and their specific functions.

Key Terms:

Neuroglia (Glial Cells): Support, protect, and nourish neurons.
CNS Glia: Astrocytes, oligodendrocytes, microglia, ependymal cells.
PNS Glia: Schwann cells, satellite cells.

Step-by-Step Guidance

List the four types of neuroglia in the CNS and two in the PNS.
For each type, write a brief description of its function (e.g., astrocytes maintain the blood-brain barrier).
Compare the roles of Schwann cells and oligodendrocytes in myelination.
Think about how these cells support neuron health and function.

Try solving on your own before revealing the answer!

Final Answer:

CNS:
- Astrocytes: Support neurons, maintain blood-brain barrier.
- Oligodendrocytes: Form myelin sheaths in CNS.
- Microglia: Act as immune defense.
- Ependymal cells: Line ventricles, produce cerebrospinal fluid.
PNS:
- Schwann cells: Form myelin sheaths in PNS.
- Satellite cells: Support neuron cell bodies in ganglia.

Each type of neuroglia has a specialized role in maintaining nervous system health.

Q4. What are the special characteristics of neurons?

Background

Topic: Neuron Structure and Function

This question tests your understanding of what makes neurons unique compared to other cell types.

Key Terms:

Excitability: Ability to respond to stimuli.
Conductivity: Ability to transmit electrical signals.
Longevity: Can live a long time.
Amitotic: Most do not divide after maturity.
High metabolic rate: Require lots of oxygen and glucose.

Step-by-Step Guidance

List the main characteristics that distinguish neurons from other cells.
For each characteristic, write a brief explanation or example.
Consider why these features are important for neuron function.

Try solving on your own before revealing the answer!

Final Answer:

Excitability: Respond to stimuli.
Conductivity: Transmit electrical impulses.
Longevity: Can last a lifetime.
Amitotic: Do not divide after development (with few exceptions).
High metabolic rate: Need constant oxygen and glucose.

These characteristics enable neurons to efficiently process and transmit information.

Q5. What are the characteristics and functions of the neuron cell body?

Background

Topic: Neuron Anatomy

This question focuses on the structure and role of the neuron's cell body (soma).

Key Terms:

Cell body (soma): Main part of the neuron containing the nucleus and organelles.
Nissl bodies: Rough endoplasmic reticulum, important for protein synthesis.
Neurofibrils: Cytoskeletal elements for support and transport.

Step-by-Step Guidance

Describe the main structures found in the cell body (nucleus, Nissl bodies, etc.).
Explain the function of each structure (e.g., Nissl bodies for protein synthesis).
Discuss the role of the cell body in maintaining neuron health and function.

Try solving on your own before revealing the answer!

Final Answer:

Contains the nucleus and most organelles.
Nissl bodies produce proteins for neuron function.
Neurofibrils provide structural support.
Integrates incoming signals and maintains cell health.

The cell body is essential for the neuron's metabolic and synthetic needs.

Q6. What is the structure and function of dendrites and axons?

Background

Topic: Neuron Processes

This question tests your knowledge of the two main types of neuron extensions and their roles.

Key Terms:

Dendrites: Short, branched extensions that receive signals.
Axon: Long extension that transmits signals away from the cell body.

Step-by-Step Guidance

Describe the physical structure of dendrites and axons.
Explain the function of dendrites (receiving input) and axons (sending output).
Discuss how signals travel from dendrites to the cell body and then down the axon.
Consider the importance of axon terminals in communication with other cells.

Try solving on your own before revealing the answer!

Final Answer:

Dendrites: Short, branched; receive incoming signals and convey them to the cell body.
Axon: Single, long process; transmits electrical impulses away from the cell body to other neurons or effectors.

Both structures are essential for neuron communication and signal transmission.

Q7. What are the different types of axonal transport and the molecules they carry?

Background

Topic: Axonal Transport

This question tests your understanding of how materials move within neurons, especially along axons.

Key Terms:

Axonal transport: Movement of substances along the axon.
Anterograde transport: From cell body to axon terminal.
Retrograde transport: From axon terminal to cell body.

Step-by-Step Guidance

Define anterograde and retrograde transport.
List examples of molecules or organelles moved by each type (e.g., neurotransmitters, mitochondria).
Consider the importance of these processes for neuron health and function.

Try solving on your own before revealing the answer!

Final Answer:

Anterograde transport: Moves materials like neurotransmitter vesicles and mitochondria from the cell body to the axon terminal.
Retrograde transport: Moves used materials and signals from the axon terminal back to the cell body.

Both types are essential for neuron maintenance and communication.

Q8. Define: Nuclei, Ganglia, Tracts, Nerves

Background

Topic: Nervous System Terminology

This question tests your knowledge of key anatomical terms used to describe groups of neuron cell bodies and axons in the CNS and PNS.

Key Terms:

Nuclei: Clusters of neuron cell bodies in the CNS.
Ganglia: Clusters of neuron cell bodies in the PNS.
Tracts: Bundles of axons in the CNS.
Nerves: Bundles of axons in the PNS.

Step-by-Step Guidance

Define each term and specify whether it is found in the CNS or PNS.
Think of examples or locations for each (e.g., dorsal root ganglia for PNS).
Compare and contrast the terms to reinforce your understanding.

Try solving on your own before revealing the answer!

Final Answer:

Nuclei: Clusters of neuron cell bodies in the CNS.
Ganglia: Clusters of neuron cell bodies in the PNS.
Tracts: Bundles of axons in the CNS.
Nerves: Bundles of axons in the PNS.

These terms help distinguish anatomical structures in different parts of the nervous system.

Q9. What is the myelin sheath and its function? How is myelin formed in the PNS and CNS? Compare and contrast myelinated and unmyelinated fibers. What is the purpose of the outer collar of perinuclear cytoplasm (neurilemma)? What are myelin sheath gaps?

Background

Topic: Myelination

This question covers the structure, formation, and function of the myelin sheath, as well as related terminology.

Key Terms:

Myelin sheath: Insulating layer around axons.
Schwann cells: Form myelin in the PNS.
Oligodendrocytes: Form myelin in the CNS.
Neurilemma: Outer layer of Schwann cell cytoplasm.
Myelin sheath gaps (Nodes of Ranvier): Gaps between myelin segments.

Step-by-Step Guidance

Define the myelin sheath and its main function (insulation, speed of conduction).
Describe how Schwann cells and oligodendrocytes form myelin in the PNS and CNS, respectively.
Compare myelinated and unmyelinated fibers in terms of structure and function.
Explain the role of the neurilemma in the PNS.
Define myelin sheath gaps and their importance in nerve impulse conduction.

Try solving on your own before revealing the answer!

Final Answer:

Myelin sheath: Insulates axons, increases speed of nerve impulse transmission.
PNS: Schwann cells wrap around axons, forming myelin and the neurilemma.
CNS: Oligodendrocytes myelinate multiple axons, no neurilemma present.
Myelinated fibers: Conduct impulses faster than unmyelinated fibers.
Neurilemma: Aids in regeneration of damaged PNS fibers.
Myelin sheath gaps (Nodes of Ranvier): Allow for saltatory conduction, speeding up signal transmission.

Myelination is crucial for rapid and efficient nerve signaling.

Q10. What is white matter and gray matter?

Background

Topic: Nervous System Tissue Types

This question tests your understanding of the composition and function of white and gray matter in the nervous system.

Key Terms:

White matter: Regions with myelinated axons.
Gray matter: Regions with neuron cell bodies, dendrites, and unmyelinated axons.

Step-by-Step Guidance

Define white matter and gray matter based on their composition.
Identify where each is found in the brain and spinal cord.
Explain the functional significance of each type of tissue.

Try solving on your own before revealing the answer!

Final Answer:

White matter: Composed mainly of myelinated axons; found in deeper brain regions and outer spinal cord.
Gray matter: Contains neuron cell bodies, dendrites, and unmyelinated axons; found in the cerebral cortex and inner spinal cord.

White matter transmits signals, while gray matter processes information.

Q11. What are the structural and functional classifications of neurons?

Background

Topic: Neuron Classification

This question tests your ability to distinguish neurons based on their structure and function.

Key Terms:

Structural classification: Multipolar, bipolar, unipolar neurons.
Functional classification: Sensory (afferent), motor (efferent), interneurons.

Step-by-Step Guidance

List the three structural types of neurons and describe their features.
List the three functional types and describe their roles in the nervous system.
Match examples of each type to their function and structure.

Try solving on your own before revealing the answer!

Final Answer:

Structural:
- Multipolar: Many dendrites, one axon (most common in CNS).
- Bipolar: One dendrite, one axon (rare, e.g., retina).
- Unipolar: Single process that splits into two branches (sensory neurons in PNS).
Functional:
- Sensory (afferent): Transmit impulses toward CNS.
- Motor (efferent): Carry impulses away from CNS to effectors.
- Interneurons: Connect sensory and motor neurons within CNS.

Understanding these classifications helps in identifying neuron roles in neural circuits.