C1. P3 Flashcards
(29 cards)
What is membrane potential?
The electrical charge on the neurons membrane
What is resting potential?
Its charge when it is not actively firing
When is a neuron in resting potential?
A neuron is in its resting potential when it has a negative charge (generally -70 millivolts [mv]) inside the cell body
How does a neuron become active?
In order for a neuron to become active its internal charge needs to become positive and then reach a threshold
What is threshold potential?
The degree of change in a neuron’s charge necessary for that neuron to begin depolarization
What are ion channels?
Doors on the membrane of the neuron that, when open, allow ions to come inside the neuron
What is depolarization?
The process by which the charge for a neuron’s membrane moves in a positive direction
How is depolarization caused?
Excitatory messages from other neurons open up the sodium ion channels making it easier for the positively charged sodium ions to enter the neuron
What happens during depolarization?
Sodium ion gates are opening and sodium is rushing in
What is repolarization?
The charge of the neuron’s membrane becomes more negative
What happens during repolarization?
Potassium ion channels open and potassium ions rush out. Since these ions are positively charged, the membranes potential rapidly drops
What is hyperpolarization?
The charge inside the neuron membrane going lower than the resting potential
What is the refractory period?
The very brief period of time immediately after a depolarization-repolarization cycle during which no amount of external stimulation can trigger a depolarization process
What are sodium-potassium pumps?
Sodium-Potassium Pumps push sodium out and pull potassium back in
What is action potential?
The chain-reaction of depolarizations and repolarizations that occur along the adjacent section of the axon’s membrane
How are neurotransmitters released?
When the charger moving down the axon reaches the axon terminals it triggers a reaction in the vesicles. This causes them to open and release neurotransmitters. These neurotransmitters then leave the cell and go over to the next neuron
How found the synapse?
Sir Charles Sherrington
What is a synapse?
A gap that allows neurons to communicate
What makes neurons fire?
It is the binding of neurotransmitters that excites or inhibits the receiving neuron
What is reuptake?
The process by which the presynaptic neuron reabsorbs neurotransmitters it previously released which did not bind to the next neuron’s receptors and are floating in the synapse
What is glutamate?
Excitatory neurotransmitter involved in thinking. learning, and memory. Most abundant in the brain
What is norepinephrine?
Excitatory neurotransmitter that increases arousal and alertness. High levels triggers anxiety, low levels trigger depression
What is epinephrine?
Adrenaline hormone that plays in role inn the fight or flight stress response
What is GABA?
Most common type of inhibitory signal. Calms nerve activity helping us sleep, reduce stress, and reduce seizures
