Download presentation
Presentation is loading. Please wait.
Published byIda Darmadi Modified over 6 years ago
1
What is the part of the neuron that receives signals? Sends them?
Daily Warm-up March 6th What is the part of the neuron that receives signals? Sends them? HW: -Read 37.3 Turn in: -Nothing
2
Ions & Resting Potential
Cell is negatively charged compared to surroundings Difference is potential energy in form of voltage Membrane potential= resting potential when neuron is at rest Stimuli can change membrane potential
3
Formation of Resting Potential
Potassium ions (higher in the cell) Sodium ions (higher outside) 1. Sodium-potassium pump Active transport Transport Na+ out of cell and K+ into cell Three Na+ for two K+ But only a few millivolts!!! So where is the charge coming from? 2. Ion channels
4
What about the Ion Channels?
Gradient favors outflow of K+ Very few open sodium channels when at rest K+ outflow causes negative charge
5
When there is a stimulus…membrane potential changes
Action potential Changes occur because of gated ion channels Open or close in response to stimuli Hyperpolarization Cell becomes more negative Depolarization Cell becomes less negative
6
Two Types of Potential Change
Graded Potential- strength depends on stimulus Action Potential- all or nothing -Constant magnitude -Regenerate along neuron membrane -Spread along axons -Signaling
7
Action Potential Voltage-gated ion channels
Open or close when membrane potential reaches threshold Depolarization of voltage-gated sodium channel? Positive feedback Potassium channel will open at end to return neuron to resting state
9
Movement of the Signal Once area rises above threshold have signal moving
10
Saltatory Conduction
11
Neuron-Neuron Communication
Some can be electrical signals, but most are chemical Neurotransmitters Communication occurs at a synapse
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.