Electrical Signals Flashcards
- Muscle contraction
- Neuron to muscle communication
- Neuron to neuron communication
- Neuron to endocrine cell communication
Electrical Signals
Ohm’s Law mathematically defines the physics of ??
Electricity
What is I in the I=V/R ?
Current
What is V in the I=V/R ?
Potential
What is the R in the I=V/R ?
Resistance
Current is generated by moving ?
electrons or ions
What is the effect of unequal charges ?
Electrical potential
The body itself is ?
Neutral
Individual cells have ___ charge because of permeability of the membrane to certain ions and protein/peptides cant cross.
Net negative charge
Concetration high outside the cell, low inside the cell
Na+
Concentration low outside the cell, high inside the cell
K+
The potential electrical energy that pushes ions inside the cell or across the membrane
Membrane Potentials
The membrane potential that is at rest when no signals are entering the cell or leaving
Resting membrane potential
RMP is ___ because movement of ion outside the cell is balanced by the movement of ions into the cell creating a balance of charges.
Stable
RMP is ___ because there are more negatively charged particles inside the cell than outside the cell.
Negative
At RMP, __ concentration is high outside the cell in ECF
Na+
At RMP, ___ Concentration is high inside the cell
K+
Works well with permeability to create currents across the membrane
The difference in Na+ and K= concentrations inside and outside the cell.
The membrane potential is more permeable to ___ at rest than ____ creating a positive current out the cell across the membrane that helps create the negative membrane potential
K+, Na+
The unequal__ pumping ratio of the Na+/K+ATPase pump that helps maintain RMP
3:2
The potential created when new current flows into or out of the cell, small changes
Graded potential (local potential)
Graded potentials build up and move down a neuron to a point where it ____
Triggers an action potential
Graded potentials are __ compared to action potentials
Small
_____ move inside the cell much faster than action potentials since they are actually just current once generated.
Graded potential
A big, characteristic change in membrane potential that carries a signal a long distance either down and axon or all over the surface of a muscle cell.
Action potential
Area of connection between neuron to neuron, or between neuron to muscle
Synapse
Chemicals that move across these synapses. These chemicals are released from nerve terminals, travel across synapse and bind to receptors on the next neuron/muscle.
Neurotransmiter
Negative charges line up along the inside of the membrane, and positive charges line up along outside of the membrane
Capacitance or membrane
Membrane potential when the movement of that ion in and out of the cell through channels in the membrane is equal.
Equilibrium potential (Nernst potential)
Same number of particles of that particular ion are leaving the cell as there are entering the cell creating an equal current from that ion going out to the current from that ion going into the cell
Equilibrium potential
The only four ions about equilibrium potential
Na+, K+, Ca++, Cl-
Have positive equilibrium potentials
Na+ and Ca++
have equilibrium potentials less than resting membrane potential of human cells
K+, Cl-
Na+ has ___ extracellular Concentration
Higher
Na+ has ___ Intracellular concentration
Lower
K+ has ___ Extracellular concentration
Lower
K+ has ____ Intracellular concentration
Higher
Cl- has ____ Extracellular concentration
Higher
Cl- has ___ Intracellular concentration
Lower
Proteins have ____Extracellular concentration
Lower
Proteins have ____ Intracellular concentration
Higher
These are channels that are always open and responsible for the permeability of the membrane to certain ions
Leaky channels
Has 3 different types. No always opening, but have to be actively opened
Gated channels
Ligand binds to receptor either on extracellular domain or intracellular dmain, channel opens or closes, ions flow in or out of cell
Chemically gated
Voltage across membrane causes channel to open or close, ions flow in or out of cell
Voltage gated
Mechanical force such as stretching or bending causes channel to open or close, ions flow in r out of cell. Hearing, balance, and touch all deal with these types of gated channels.
Mechanically gated
Opening or closing of chemically or mechanically gated channels lead to ____
current flowing in or out of the cell, thus creating Graded potential
Can be depolarizing, which is making the cell more positive than resting membrane potential or hyper-polarizing. Making the cell more negative than RMP
Graded Potential
Doesnt decay, all or none , amplitude remains the same down the axon
Action Potential
In action potentials , they are slow to open at initial depolarization, but are fully open when repolarization
K+ channels
In action potentials, they become inactivated during re polarization
Na+ channels
___ channels are either closed, open, or inactivated
Na+
Channels are either open or closed and do not have an inactivation gate
K+
when areas of the axon or membrane cant generate action potential, they are called ____
Refactory
2 types of refactory
Absolute and Relative
None of the channels have completely reset, and no action potential can occur. Seen during depolarization and more of repolarixtion
Absolute
Some channels have reset, small action potentials can be generated but the stimulus has to be very strong. Seen near the end of re-polarization
Relative
Cell that sends signal
Pre synaptic neuron
Cell that receives that signal. Can be neuron or muscle
Post synaptic cell
In neuron to muscle process, the neurotransmitter released is ___
Acetylcholine
Acetylcholine binds to ___receptor on muscle cell, changing its shape and allowing Na+ to com in, creating a ___
Nicotinic cholinergic, graded potential
Changes in membrane potential that are moving closer to zero mv, electrically neutral. Making it more positive than resting potential
Depolarization
changes in membrane potential thats moving further from zero mv , Making it more negative than resting potential.
Hyperpolarization
Return of membrane potential back to resting potential after a large depolarization like the rising phase of the action potential
Repolarization
How fast is action potentials
2-10 msec
The cell that is sending the signal
Pre-Synaptic neuron
The cell that is receiving the signal
Post synaptic cell
Where the neurotransmitter is usually stored
synaptic vesicles
chemical synapses releases a chemical known as _____
Neurotransmitter, into a synaptic cleft
