Nervous coordination

• The voltage at resting potential is -70mV
• At the resting membrane, there are more Na+ outside than inside and more K+ inside than out.
• Na+ channels open when stimulated by an action potential, allowing Na+ to enter the cell down its concentration gradient.
• K+ channels close during depolarization, preventing further loss of positive charge from the cell.
• When an action potential occurs, sodium channels open allowing Na+ to rush into the cell down its concentration gradient.
• Resting potential is maintained by sodium-potassium pump and potassium channels.
• During resting potential, sodium-potassium pump use active transport to move 3 sodium ions out of the neurone and 2 potassium ions to move in. This uses ATP
• Sodium channels only open at threshold voltage (around -50mV)
• Potassium ion channels allow facilitated diffusion of potassium ions out of the neurone, down their concentration gradient.
• Synaptic vesicle contains chemicals called neurotrasmitters.
• Impulses are unidirectional. because they can only travel in one direction. Receptors are found only on the post-synaptic membrane.
• Acetylcholine is a neurotransmitter , which binds to cholinergic receptors. Synapses that use acetly choline are called cholinergic synapses.