Week 7 Flashcards
1
Q
What are the 4 ion channels?
A
Passive ion channels
Ligand gated ion channels
Mechanically gated ion channels
Voltage gated ion channels
2
Q
Passive Ion Channel:
A
- Transmembrane Channels
- Always open
- Ions move along electro-magnetic gradient
- Ions move along concentration gradient
- Ions move along gradient to achieve their equilibrium membrane potential
3
Q
What are the two types of gradients ions can move along?
A
Electro-magnetic gradient (moves to the opposite charge) Concentration gradient (moves to the lower concentration of ions)
4
Q
Ligand Gated Ion Channels:
A
- Stimulated/ Controlled by Ligand binding to surface
- Ligand: hormone or a neurotransmitter
5
Q
What happens to the neurotransmitter when it leaves the surface channel?
A
- Dissociated by enzyme
- Goes into blood
- Returns to synaptic bulbs
6
Q
Voltage gated ion channels:
A
- Simulated by the surrounding charge
- Located in axon hillock: Na channels
- Located in the axon terminal: Ca channels
7
Q
Where on the neuron is the AP initiated?
A
The axon hillock (at voltage gated ion channels)
8
Q
Mechanically gated ion channel:
A
- Simulated by change in environment
- e.g. Skin, ear, hairs in nose (movements of these hairs)
9
Q
Role of the Na/ K Pump:
A
- Set up the ion gradient
- Regulate concentration (ensure more sodium outside the cell and potassium inside)
- NOT THE MAIN FUNCTION FOR CHANGING RMP: Dr. Pete the CTL man
10
Q
Is the Na/K Pump the main function for changing RMP:
A
NO WAY MATE ;)
11
Q
Where is there more Na (extracellular or intracellular) and what is the concentration:
A
Extracellular
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