Neuronal Communication

• Stimuli


  Changes in the external or internal environment that can trigger a response
• Response


  An appropriate reaction that is triggered by the processed information received from stimuli
• Central Nervous System (CNS)


  The brain and spinal cord, responsible for processing and coordinating information
• Peripheral Nervous System


  Nerves outside the CNS that transmit information between the CNS and the rest of the body
• Neurones


  Specialized cells responsible for transmitting electrical signals, enabling communication within the nervous system
• Motor Neurone


  A type of neurone that transmits impulses away from the CNS to an effector (muscle, gland, or organ)
• Sensory Neurone


  A type of neurone that transmits impulses to the CNS from a receptor, detecting stimuli
• Relay Neurone


  A type of neurone that transmits impulses between sensory and motor neurones, facilitating communication within the nervous system
• Cell Body


  The main part of a neurone that contains the nucleus, endoplasmic reticulum (ER), and mitochondria
• Dendrites


  Branch-like nerve fibres that carry impulses towards the cell body, receiving signals from other neurones
• Axons


  Long, elongated nerve fibres that carry impulses away from the cell body, transmitting signals to other neurones or effectors
• Effector


  A muscle, gland, or organ that responds to a stimulus, producing a specific action or response
• Schwann Cells


  Cells that form the myelin sheath around axons in the Peripheral Nervous System (PNS), providing insulation and promoting faster impulse transmission
• Myelin Sheath

  An insulating layer around axons, formed by Schwann cells in the PNS, which enhances the speed of impulse transmission
• Nodes of Ranvier


  Gaps in the myelin sheath along axons, allowing for faster impulse transmission by enabling saltatory conduction
• Multiple Sclerosis


  A disease that affects the myelin sheath, leading to impaired nerve function and communication within the nervous system
• Saltatory Conduction


  The rapid transmission of impulses from one node of Ranvier to the next, skipping the myelinated regions of the axon
• Sensory Receptors

  Specialized cells that detect changes in the environment
• Sense Organs


  Locations where sensory receptors are often found
• Stimulus


  A change in the environment that sensory receptors detect
• Nerve Impulse


  An electrical signal generated by sensory receptors in response to a stimulus
• Central Nervous System (CNS)


  The part of the nervous system that receives and processes nerve impulses
• Effector


  A muscle or gland that responds to nerve impulses from the brain
• Spinal Cord


  The part of the nervous system that relays nerve impulses between the body and the brain
• Sensory Neuron


  A neuron that carries nerve impulses from sensory receptors to the CNS
• Motor Neuron


  A neuron that carries nerve impulses from the CNS to effectors
• Relay Neuron


  A neuron that relays nerve impulses between sensory and motor neurons
• Transducer


  A device that converts one form of energy into another
• Generator Potential

  A nerve impulse produced by sensory receptors in response to a stimulus
• Pacinian Corpuscle


  A sensory receptor cell that detects mechanical pressure
• Sensory Nerve Ending


  The end of a sensory neuron that is part of the Pacinian corpuscle
• Connective Tissue


  Tissue that surrounds and supports the sensory nerve ending in the Pacinian corpuscle
• Stretch-Mediated Sodium Channels

  A special type of sodium channels in the membrane of the Pacinian corpuscle that open when stretched
• Resting Potential


  The normal state of the Pacinian corpuscle where sodium channels are too narrow to let sodium ions through
• Depolarized


  A change in the membrane potential of the Pacinian corpuscle due to sodium ions entering
• Action Potential


  A nerve impulse generated by the Pacinian corpuscle if the generator potential exceeds the threshold
• Threshold


  The minimum level of generator potential required to generate an action potential
• Propagation


  The transmission of the action potential along the sensory neuron
• Resting potential


  The charge difference between the inside and outside of a neuron when it is at rest
• Voltage


  The potential difference across the membrane of a neuron