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.