07a Nervous System with notes + Audio Pointer sp 2020 sp21 [Autosaved]

Page 1: Introduction to the Vertebrate Nervous System

• The vertebrate nervous system is a complex network responsible for the coordination of various body functions.

• Humor in communication can highlight the intricate nature of brain function.

Page 2: Overview of Nervous System Communication

• The nervous system utilizes electrical communication, primarily through the following characteristics:

  • Unidirectional Communication: Signals travel in one direction from one neuron to another.

  • Speed: Electrical signals are rapid, allowing for quick responses.

  • Mechanism: Requires action potentials and neurotransmitters at synapses, facilitating cell-to-cell signaling.

Page 3: Mechanism of Action Potentials

• Electrical Polarity: Created by a charge difference inside vs. outside the neuronal membrane.

• Ion Pumps: Such as the Na-K pump, establish concentration and voltage gradients, leading to membrane polarization.

• Depolarization: Occurs when ion channels open, allowing ions to flow through, thus leading to a wave-like depolarization of the membrane.

Page 4: Neuronal Communication and Action Potential

• Action Potential: A fundamental change in membrane potential that serves as the basis for neuronal signaling.

• Visual aids can be beneficial in understanding action potential dynamics.

Page 5: Neuronal Communication Visuals

• GIF assets can help illustrate the process of action potential.

Page 6: Ion Channel Functionality

• Ion channels are critical for neuronal function:

  • Closed Channels: Prevent ion movement.

  • Open Channels: Allow ions to flow, continuing the action potential.

  • Selective Filters: Channels that only permit specific ions to cross.

Page 7: Membrane Depolarization Mechanisms

• Channel Protein Dynamics: A neuron’s response to stimuli involves:

  • Voltage-gated: Channels that open in response to membrane potential changes.

  • Ligand-gated: Channels that open in response to the binding of neurotransmitters or other signaling molecules.

  • Deformation-induced: Channels that respond to physical changes in the membrane.

Page 8: Fundamental Components of Neuronal Communication

• Structure Overview: Neurons consist of parts that play distinct roles in signal transmission, including dendrites and axons.

Page 11: Structure of a Neuron

• Dendrites: Receive stimuli at synapses.

• Cell Body: Maintains cellular function and energy management.

• Axon: Transmits signals to other cells via synapses.

• Synapse: The junction where communication occurs between two neurons.

Page 14: Synaptic Transmission Mechanism

• Neurotransmitter Release: Action potentials prompt neurotransmitter release, which facilitates communication with the postsynaptic neuron.

• Triggering Potential: This action opens ion channels in the postsynaptic neuron, potentially initiating a new action potential.

Page 16: Types of Nervous System Cells

• Neurons: Diverse types, including:

  • Unmyelinated: Lack a myelin sheath.

  • Myelinated: Have a myelin sheath that aids in rapid conduction.

• Glia: Supportive cells in the nervous system.

• Sensory Receptors: Including:

  • Photoreceptors: For vision.

  • Mechanoreceptors: For touch and sound.

  • Chemoreceptors: For taste and smell.

  • Nociceptors: For pain sensations.

Page 17: Central and Peripheral Nervous Systems

• CNS Overview:

  • Brain: Central control unit of the body governing functions and reflexes.

  • Spinal Cord: Facilitates reflex actions and relays information between the brain and body.

Page 19: Peripheral Nervous System Components

• PNS Overview: Contains peripheral nerves that extend to:

  • Sensory Organs: Convey contextual sensory information.

  • Motor Functions: Facilitate movement and response away from the CNS.

Page 20: The Reflex Arc Structure

• The reflex arc involves integration between the CNS and PNS, coordinating reflex actions through:

  • Sensory neurons communicating with interneurons and motor neurons within the spinal cord.

Page 30: Reflex Arc Components

• Illustrates the connection between sensory and motor neurons within the spinal cord that coordinate reflexive responses.

Page 31: Human Senses: Taste

• Mechanism involves ligand-gated receptors within the oral cavity.

• Key components include:

  • Amino Acids and Sugars: Recognized by specific receptors

  • Umami and Bitter Receptors: Specialized receptor types linked to specific chemical structures.

Page 32: Human Senses: Smell

• Olfactory System Anatomy: Involves:

  • Nerve Fibers: Within the olfactory bulb that connect to the brain.

  • Columnar Epithelial Cells: Supporting cells in the nasal cavity.

Page 34: Human Senses: Hearing

• Hearing Mechanism Overview:

  • Outer Ear: Captures sound waves.

  • Middle Ear: Transmits vibrations.

  • Inner Ear (Cochlea): Houses hair cells that detect sound.

Page 36: Human Senses: Touch

• Involves mechanically gated channel proteins that alter neuronal polarization in response to stimuli.

Page 37: Human Senses: Vision

• Vision relies on ligand-gated mechanisms, where light induces conformational changes in retinal proteins, influencing ion channel activity.

Page 40: Vision Pathway to Brain

• The optic pathway includes:

  • Optic Nerves and Chiasm: Transfer visual information.

  • Thalamus: Processes visual signals to cortical areas.