37.1
This part of the neuron is like the main body and contains most of its organelles
cell body (or soma)
What is the "electro" part of an electrochemical gradient
"Like" ions repelling one another, "Opposite" ions attracting one another
Neurons have special protein channels called
Gated ion channels
What term describes the voltage across the plasma membrane of a cell?
Membrane potential
What is an example of a disorder where a mutation encoding ion channel proteins affects an individual?
Will take many answers
These highly branched extensions are responsible for receiving signals from other neurons
dendrites
Define a neuron's resting membrane potential
The membrane potential of a resting neuron
What membrane potential makes the inside more negative and less likely to fire immediately again?
Hyperpolarization
Name 2 types of gated ion channels that are involved in action potentials
Sodium and potassium or chlorine
How much do glial cells outnumber neurons?
10- to 50-fold in the mammalian brain
This single, long extension transmits signals away from the cell body to other cells
axon
What doest the Nernst Equation assume?
The body is at room temperature
The ion involved has a +1 charge
Depolarization triggers a full action potential when
the neuron reaches a certain level called threshold
What depolarizes the axon membrane ahead of the action potential cannot produce another action potential behind it?
Inward current
This brief, all-or-nothing electrical impulse travels rapidly down the axon and is the main way neurons transmit signals over long distances
action potential
The cone-shaped base of an axon where signals that travel down the axon are generated
axon hillock
If the resting membrane potential of a neuron is at -60, is it closer to the Eion of Na+, or K+?
K+
What ion channels are temporarily inactivated during the refractory period?
Sodium
What is the electrical insulation that surrounds vertebrate axons, and what produces it? (MUST KNOW BOTH PARTS)
myelin sheath; glia
If John Joey Junior's neuron has more sodium ion channels open than potassium ion channels, what happens to the equilibrium potential?
It becomes more positive and moves towards the Eion of Na+'s equilbrium potential
Chemical messengers that carry information across the synapse
neurotransmitters
What is the role of Na+ in maintaining the resting potential?
It will tug the resting potential towards positivity, ensuring that there is always a net flow of ions across the membrane
Why is the refractory period important?
limits the number of action potentials a neuron can produce
What causes action potentials to jump nodes?
Saltatory conduction OR extracellular fluid contacts the axon membrane only at the nodes
Schwann cells are a type of what?
Glial Cell