Synaptic transmission/nerve impulses

Question 1

resting potential

Answer 1

not stimulated or involved in passage of impulse

neuron is more negatively charged, while the outside of the neuron is more positively charged

Question 2

action potential

Answer 2

reverse in electrical charge occurs across the membrane of a neuron in its resting state.

inside of the neuron becomes more positively charged, while the outside of the neuron becomes more negatively charged

reverse in charge travels down the axon as an electric current

Question 3

Electrical synapse steps

Answer 3

Once the action potential reaches the terminal bulbs of the axon terminal, the synaptic transmission process begins.

An action potential travels down the axon and reaches the terminal branches of the axon.

Voltage gated sodium gates open, causing sodium to enter the axon terminal bulb.
Voltage gated Ca2+ channels open at the same time.
Calcium ions move into the axon terminal bulb of the presynaptic neuron.
Calcium ions bind with proteins on synaptic vesicles that carry chemical messages called neurotransmitters.
This binding causes the vesicles to contract and move to the presynaptic membrane.
Neurotransmitters are released from the vesicles via exocytosis and diffuse across the synaptic cleft.
Neurotransmitters bind with receptors on the postsynaptic membrane of a neuron, gland, or muscle.
Depending on what the postsynaptic target cell is, the following responses will happen:
Axon to dendrite: Action potential travels to next neuron.
Axon and muscle cell: Muscle contraction.
Axon and gland: Hormones released from gland.