Lab 11 12 Practice

Lab 11-12 Practice: Notes on Cranial Nerves and Nervous System Structures

Cranial Nerves and Their Functions

  1. Olfactory Nerve (I)

    • Function: Smell

  2. Optic Nerve (II)

    • Function: Vision

  3. Accessory Nerve (XI)

    • Function: Shoulder Shrug

Nervous System Diagram Components

Diagram Elements:

  • Nucleus of Schwann Cell

    • These are supporting cells in the peripheral nervous system (PNS), critical for myelination of peripheral axons.

  • Dendrites

    • The structures of a neuron that receive messages from other nerve cells.

  • Synaptic Knob of Axon Terminal

    • The end of the neuron that communicates with the next nerve or muscle, releasing neurotransmitters.

  • Axon

    • The long, tail-like structure that conducts impulses away from the neuron's cell body.

  • Nucleus

    • The control center of the neuron, containing genetic material.

  • Nucleolus

    • Located within the nucleus; it is responsible for ribosomal RNA synthesis and assembly.

  • Neurofibrils

    • Fine strands within the neuron that provide structural support and transport materials.

  • Cell Body

    • The part of the neuron that contains the nucleus and organelles; it integrates signals and maintains cell health.
Definitions of Key Structural Components

  1. Area that is Unmyelinated and Consists of Nodes of Ranvier:

    • The Nodes of Ranvier are gaps in the myelin sheath where the axon is exposed; they facilitate rapid transmission of nerve impulses through saltatory conduction.

  2. Area that Brings All Sensory Information to the Cell Body:

    • Dendrites play this role, receiving sensory input from other neurons and carrying that information toward the cell body for processing.

  3. Control Center for All Information that Enters the Cell:

    • The nucleus serves as the control center where neuronal information is processed and decisions are made based on incoming signals.

  4. Substance that Allows for Faster Transmission of the Impulse:

    • Myelin is the substance that covers the axon and enables quicker impulse transmission by insulating the nerve and preventing signal loss; this also includes the effects of the Nodes of Ranvier in facilitating faster propagation via saltatory conduction.