Nervous System Overview and Functions
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Questions and Answers

The nervous system is responsible for coordinating what two aspects of the body?

Actions and sensory information

What are the two main divisions of the nervous system?

  • Somatic nervous system and Autonomic nervous system
  • Central nervous system and Peripheral nervous system (correct)
  • Sympathetic nervous system and Parasympathetic nervous system

What does the CNS consist of?

Brain and spinal cord

What are the two main types of cells in the nervous system?

<p>Neurons and neuroglia</p> Signup and view all the answers

What is the role of neuroglia in the nervous system?

<p>Support and protect neurons</p> Signup and view all the answers

What are three main types of connective tissue cells in the CNS?

<p>Astrocytes, microglia, and oligodendrocytes</p> Signup and view all the answers

What are the three parts of a neuron?

<p>Cell body, dendrites, and axon</p> Signup and view all the answers

What type of neuron causes muscle contractions and controls secretions from glands and organs?

<p>Motor neuron</p> Signup and view all the answers

What is the name of the fatty layer that insulates the axon of a motor neuron?

<p>Myelin sheath</p> Signup and view all the answers

What is the definition of a synapse?

<p>The place where impulses are transmitted from one neuron to another</p> Signup and view all the answers

What are the three structures that make up a synapse?

<p>Synaptic knob, synaptic cleft, and plasma membrane</p> Signup and view all the answers

What role do neurotransmitters play in a synapse?

<p>They bind to specific receptor molecules in the membrane of a postsynaptic neuron</p> Signup and view all the answers

What is an action potential?

<p>A self-propagating wave of electrical disturbance that travels along the surface of a neuron membrane</p> Signup and view all the answers

At rest, a neuron's membrane is slightly positive on the outside. What is this state called?

<p>Polarized</p> Signup and view all the answers

What happens when a stimulus triggers the opening of Na+ channels in a neuron's plasma membrane?

<p>Depolarization occurs</p> Signup and view all the answers

The central nervous system controls most functions of the body and mind, including voluntary and involuntary movements.

<p>True (A)</p> Signup and view all the answers

What are the three parts of the brain stem?

<p>Medulla oblongata, pons, and midbrain</p> Signup and view all the answers

Where does the pons lie?

<p>Between the medulla oblongata and the midbrain</p> Signup and view all the answers

What are the three meninges?

<p>Dura mater, arachnoid, and pia mater</p> Signup and view all the answers

What is the name of the fluid that surrounds the brain and spinal cord?

<p>Cerebrospinal fluid</p> Signup and view all the answers

What are the main functions of cerebrospinal fluid?

<p>Protects brain and spinal cord from trauma, supplies nutrients to nervous system tissue, and removes waste products from cerebral metabolism</p> Signup and view all the answers

The spinal cord has 36 segments in total.

<p>False (B)</p> Signup and view all the answers

How is the spinal cord protected?

<p>By the vertebrae</p> Signup and view all the answers

Gray matter contains cell bodies, while white matter contains myelinated fibers.

<p>True (A)</p> Signup and view all the answers

What are the two types of nerves that branch out and connect to the peripheral nervous system at each segment of the spinal cord?

<p>Sensory and motor nerves</p> Signup and view all the answers

What is a reflex arc?

<p>The simplest neural pathway</p> Signup and view all the answers

Reflex arcs occur before the brain is aware of the response.

<p>True (A)</p> Signup and view all the answers

What is the name of the lobe of the brain that is responsible for voluntary movements, personality, and speech?

<p>Frontal lobe</p> Signup and view all the answers

What is the name of the lobe of the brain that is responsible for vision?

<p>Occipital lobe</p> Signup and view all the answers

What is the name of the lobe of the brain that is responsible for hearing, smell, and language input?

<p>Temporal lobe</p> Signup and view all the answers

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Flashcards

What is the nervous system?

The nervous system is the communication network of the body. It collects information from the environment, processes it, and initiates responses.

What is the CNS?

The central nervous system (CNS) is the command center of the nervous system, containing the brain and spinal cord.

What is the PNS?

The peripheral nervous system (PNS) is the network of nerves that connect the CNS to the rest of the body, like an intricate web of communication.

What are motor neurons?

Motor neurons carry signals from the CNS to muscles and glands, telling them what to do. Think of them as messengers carrying instructions.

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What are sensory neurons?

Sensory neurons carry signals from sensory organs to the CNS, providing information about the environment. Think of them as information gatherers.

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What is the somatic nervous system?

The somatic nervous system controls voluntary movements, like moving your arm or typing on a keyboard. It's your conscious control.

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What is the autonomic nervous system?

The autonomic nervous system controls involuntary responses, like breathing or digestion. It's the body's automatic pilot.

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What is the sympathetic division?

The sympathetic division of the autonomic nervous system prepares the body for stressful or energetic activity, like 'fight or flight'. It's the adrenaline rush.

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What is the parasympathetic division?

The parasympathetic division of the autonomic nervous system dominates during times of 'rest and rumination', helping the body conserve energy and recover. It's the 'relax' mode.

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What are neurons?

Neurons are the basic building blocks of the nervous system, they are specialized cells that transmit nerve impulses. Like tiny electrical wires.

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What are neuroglia?

Neuroglia are supporting cells that provide structural and functional support to the nervous system like the glue that holds everything together.

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What is the cell body of a neuron?

The cell body of a neuron contains the nucleus and other organelles, it's like the neuron's central powerhouse.

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What are dendrites?

Dendrites are branching projections that receive signals from other neurons, like the receiving antennas of the neuron.

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What is an axon?

The axon is a long, slender projection that carries signals away from the cell body, it's like the transmission cable of the neuron.

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What are the characteristics of motor neurons?

Motor neurons have one axon and many dendrites, they specialize in transmitting signals from the CNS to muscles and glands.

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What are the characteristics of sensory neurons?

Sensory neurons lack true dendrites, they are attached to sensory receptors and transmit signals from the environment to the CNS.

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What are interneurons?

Interneurons are located entirely within the CNS, they connect sensory and motor neurons, acting like the nervous system's internal communicators.

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What are astrocytes?

Astrocytes are star-shaped neuroglia that anchor blood vessels to neurons, providing structural support and regulating the environment around them.

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What are microglia?

Microglia are small neuroglia that move in inflamed brain tissue, acting like the nervous system's immune cells by engulfing debris and pathogens.

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What are oligodendrocytes?

Oligodendrocytes are neuroglia that form myelin sheaths around axons in the CNS, insulating and speeding up nerve impulse transmission.

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What are Schwann cells?

Schwann cells are neuroglia that form myelin sheaths around axons in the PNS, insulating and speeding up nerve impulse transmission.

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What is a synapse?

A synapse is the junction between two neurons, where nerve impulses are transmitted from one neuron to the next.

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What are neurotransmitters?

Neurotransmitters are chemical messengers that transmit signals across synapses, allowing neurons to communicate with each other.

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What are action potentials?

Action potentials are electrical signals that travel along the surface of a neuron membrane. It's how neurons transmit information.

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What is the brain?

The brain is the control center of the CNS, responsible for thoughts, emotions, memories, and controlling bodily functions.

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What is the spinal cord?

The spinal cord is a long, thin bundle of nerve fibers that run down the back, connecting the brain to the rest of the body.

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What is gray matter?

Gray matter is the outer layer of the brain and spinal cord, it contains nerve cell bodies and unmyelinated fibers.

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What is white matter?

White matter is the inner layer of the brain and spinal cord, it contains myelinated nerve fibers, which allow for faster signal transmission.

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What are meninges?

The meninges are three protective membranes that surround the brain and spinal cord, providing cushioning and support.

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What is cerebrospinal fluid?

Cerebrospinal fluid (CSF) is a clear fluid that circulates around the brain and spinal cord, providing cushioning and nourishment.

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What are reflex arcs?

Reflex arcs are simple neural pathways that allow for rapid responses to stimuli, such as pulling your hand away from a hot object.

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Study Notes

Nervous System Overview

  • The nervous system is a complex network coordinating body actions and sensory information.
  • It transmits signals between different parts of the body.
  • It detects and responds to environmental changes.

Nervous System Divisions

  • Central Nervous System (CNS):
    • Comprises the brain and spinal cord.
    • Processes information and initiates actions.
  • Peripheral Nervous System (PNS):
    • Network of nerves and neural tissues.
    • Branches throughout the body.
    • Transmits signals between the CNS and body.
    • Consists of sensory and motor nerves.

Neurons

  • Nerve cells that are the structural and functional units of the nervous system.
  • Conduct impulses for communication.
  • Consist of three parts:
    • Cell body (main part):
    • Dendrites (branching projections): Receive impulses to the cell body.
    • Axons (elongated projection): Sends impulses away from the cell body.

Types of Neurons

  • Motor neurons:

    • Cause muscle contractions.
    • Control gland secretions.

  • Sensory neurons:

    • Do not have true dendrites.
    • Connected to sensory receptors.
    • Transmit impulses to the CNS.

  • Interneurons:

    • Found entirely within the CNS.
    • Receive impulses from sensory neurons.
    • Transmit signals to motor neurons.

Neuroglia

  • Supporting cells providing structural and functional support to nervous tissue in the CNS.
  • Types:
    • Astrocytes: Anchor blood vessels to neurons.
    • Microglia: Move in inflamed brain tissue, carrying out phagocytosis.
    • Oligodendrocytes: Form myelin sheaths in the CNS. (Schwann cells form myelin sheaths in the PNS).

Nerve Fibers

  • Bundles of nerve fibers forming nerves.
  • Schwann cells insulate axons in the PNS.

Synapses

  • Junctions where impulses are transmitted from one neuron to another (postsynaptic neuron).
  • Made up of synaptic knob, synaptic cleft, and plasma membrane.

Neurotransmitters (Examples)

  • Acetylcholine: Activates muscles.
  • Dopamine: Control of movement.
  • Epinephrine: Stress response.
  • Serotonin: Mood, sleep.
  • Endorphins: Mood, pain reduction.
  • Nitric Oxide: Memory storage.

Action Potential (Nerve Impulses)

  • Self-propagating wave of electrical disturbance along a neuron's membrane.

Mechanism of Action Potential

  • At rest, the neuron's membrane is slightly positive outside due to sodium ion excess.

  • A stimulus triggers sodium channels opening in the plasma membrane.

  • Inward movement of sodium depolarizes the membrane inside the cell locally making the inside more positive than the outside.

  • Depolarization triggers the next section of membrane to depolarize propagating an electrical disturbance along the membrane.

Divisions Of The Brain

  • Brainstem:
    • Medulla oblongata, pons, midbrain.
    • Regulates vital functions such as breathing and heart rate.
  • Cerebellum:
    • Coordinates voluntary and involuntary movements.
    • Maintains body posture.

Brain Lobes

  • Frontal lobe: Motor activity, personality, and speech.
  • Parietal lobe: Language, temperature, pressure, and touch interpretation.
  • Temporal lobe: Hearing, smell, and language interpretation.
  • Occipital lobe: Vision.

Spinal Cord

  • Protected by the vertebrae.
  • Gray matter: Contains cell bodies.
  • White matter: Contains myelinated fibers.
  • Has 31 segments (8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal).
  • Pairs of sensory and motor nerves branch out at each segment.

Cerebrospinal Fluid (CSF)

  • Cushions the brain and spinal cord.
  • Protects them from shocks.
  • Maintains a level around 1/2 to 2/3 cup.
  • Removes waste products and supplies nutrients to nervous system tissue. Important for proper brain function.

Reflex Arcs (Reflex Activity)

  • Nerve impulses from receptors to effectors via neuron pathways (reflex arcs).
  • Simplest reflex arc: Two-neuron arc: Sensory neurons synapse in the spinal cord with motor neurons.
  • Sensory neurons receive stimulus from sensory receptors.
  • Association or interneurons connect them to motor neurons.
  • Motor neurons transmit signals to effectors (like muscles or glands) causing their response.
  • Response happens before the brain is aware.

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Description

Explore the complexities of the nervous system, including its main divisions: the Central Nervous System (CNS) and the Peripheral Nervous System (PNS). Learn about neurons, their structure, and the various types that play critical roles in communication within the body. This quiz will test your understanding of how the nervous system coordinates actions and responses to the environment.

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