1 / 16

Neuron Physiology

Neuron Physiology. Functional Properties of Neurons. Irritability – ability to respond to stimuli Conductivity – ability to transmit an impulse.

astin
Download Presentation

Neuron Physiology

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Neuron Physiology

  2. Functional Properties of Neurons • Irritability – ability to respond to stimuli • Conductivity – ability to transmit an impulse

  3. A nerve impulse does not flow like electricity because:1. Neurons conduct impulses at a slower rate than electric current 2. Neuron provides energy for transmission once it’s been stimulated. Wire is a passive conductor and requires a steady, outside energy source for continuous flow of electrons.

  4. How can stimuli of different intensities be identified? Ex: light tap on arm vs. punch -vary the # of impulses sent -vary the # of neurons triggered (the speed & duration of nerve impulse is always the same) Characteristics of Nerve Impulses

  5. What is saltatory conduction? -fastest method of nerve impulse conduction; nerve impulse jumps from one node of Ranvier to another; occurs only in myelinated neurons (like the difference between flying & driving) Characteristics of Nerve Impulses

  6. See diagram & graph Transmission of a Nerve Impulse

  7. Starting a Nerve Impulse • The plasma membrane at rest is polarized • Fewer positive ions are inside the cell than outside the cell

  8. Starting a Nerve Impulse • Depolarization – a stimulus depolarizes the neuron’s membrane • A deploarized membrane allows sodium (Na+) to flow inside the membrane • The exchange of ions initiates an action potential in the neuron

  9. The Action Potential (Nerve Impulse) • If the action potential (nerve impulse) starts, it is propagated over the entire axon • Potassium ions rush out of the neuron after sodium ions rush in, which repolarizes the membrane • The sodium-potassium pump restores the original configuration • This action requires ATP

  10. Nerve Impulse Propagation • The impulse continues to move toward the cell body

  11. Continuation of the Nerve Impulse between Neurons • Impulses are able to cross the synapse to another nerve • Neurotransmitter is released from a nerve’s axon terminal • The dendrite of the next neuron has receptors that are stimulated by the neurotransmitter • An action potential is started in the dendrite

  12. Synapse - a junction or gap between the axon of one neuron with the dendrites of another neuron Neurotransmitter - a chemical that changes the permeability of the cell membrane to a specific type of ion - initiates an action potential Ex: acetylcholine, serotonin, norepinephrine, GABA Diagram of Synaptic Transmission (synaptic cleft, vesicle, neurotransmitter, axon, dendrite, & receptor) Synaptic Transmission

  13. animation/tutorial Synaptic Transmission

  14. How Neurons Communicate at Synapses

  15. Review: Video Clip

  16. The End!

More Related