Neuro- Electrical signaling

Which of the following is communication w/in 1 neuron?

Electrical signaling

Which of the following is communication b/t 2 neurons?

Synaptic transmission

Where does a synaptic transmission occur?

at the synapse

True or false: only a chemical signal occurs at synapse?

False

True or false: a chemical and electrical signal both occur at synapse?

True

What is the first step of a signal?

Graded potential

What is the second step of a signal?

action potential

Which of the following has an electrical signal going from axon hillock to axon terminal?

action potential

Which of the following has a signal going from dendrite to axon hillock?

graded potential

True or false: one graded potential is usually enough to begin an action potential.

False

True or false: multiple graded potentials are usually required to begin an action potential.

True

What part of the axon receives the signal?

dendrite

When do chemical signals turn to electrical signaling?

charged ions flowing in/out after channels open

What are neurons able to rapidly change?

resting membrane potential

What type of energy is concentrated when opposite forces are seperated?

potential

What is voltage a measure of?

potential energy

A greater charge different across the plasma membrane will result in what?

higher voltage

Conductor and insulator are examples of basic principle of electricity?

resistance

Current is the flow of an electrical charge, what is that flow dependent on?

voltage and resistance

The membrane’s oily core and myelin allowing less leaking is an example of what type of resistance?

insulator

Salty water having low resistance, allowing ions to move more quickly is an example of what type of resistance?

conductor

What does the equation current = voltage/resistance represent?

Ohm’s law

Current is directly proportional to which?

voltage

Current is inversely proportional to which?

resistance

The inside of the cell has what type of charge?

negative

The outside of the cell has what charge?

positive

What ion leaks out of the cell causing the inside to become more negative, and the outside to become more positive?

K

What does the inside of the cell consist of that makes it negative?

K, negatively charged ions

What does the outside of the cell consist of that makes it positive?

Na, Cl, Ca

What is the average level of resting membrane potential?

-65 to -70

Which of the following channels are always open? What do they allow more of to leak?

leakage channel; K

Leakage is which of the following?

nongated

chemically, voltage, and mechanically gated channels fall under what?

Gated

When gated channels are open, how do ions diffuse along the chemical concentration gradient?

quickly from high to low concentration

When gated channels are open, how do ions diffuse along the electrical concentration gradient?

toward opposite electrical charge

How is the membrane described as?

polarized

Differences in ionic composition of ICF and ECF are able to generate what?

resting membrane potential

ICF has a higher concentration of what?

K

ECF has a higher concentration of what?

Na

Plasma membrane is more permeable to what ion?

K

What main pump is able to stabilize resting membrane potential?

Na/K ATPase

Na/K ATPase pumps what?

3Na out of cell, 2K in

Which of the following is described by incoming short signal?

graded potential

Which of the following is described by long distance signals of axons?

action potential

Which of the following is described by decrease in membrane potential, towards zero or above?

depolarization

Which of the following is described by increase in membrane potential, more negative than resting membrane potential?

hyperpolarization

True or false: Action potential do not decay over distance?

True

During resting state, what gates are open?

leakage channels and inactivation gates

What ion has an influx into the cell to cause depolarization?

Na

What is the threshold where positive feedback causes openings of Na channels?

-55

What occurs during repolarization?

Na channels close, K channels open

During depolarization what occurs to ICF electric state?

becomes less negative

What is described by a return to resting membrane potential?

repolarization

How does hyperpolarization occur?

K channels remain open while Na channels reset

True or false: all depolarization events produce action potentials.

False

True or false: not all depolarization events produce action potentials.

true

What is described by an action potential happening completely or not at all?

all or none

Which of the refractory periods does not allow for any action potential to occur at all?

absolute refractory periods

What are the reasons for a refractory period?

ensures each AP is all or none

enforces one-way transmission

Which of the refractory periods does allow for an action potential to occur if strong stimuli is present?

relative refractory period

Where do APs occur?

axon

What does axon diameter and degree of myelination affect?

rate of progression of AP

What type of conduction occurs if there is no myelination present?

continuous conduction

What type of conduction occurs if there is myelination present?

saltatory conduction

Which type of conduction is slow and occurs on unmyelinated axons?

continuous conduction

What type of conduction is fast?

saltatory conduction

Where are the voltage gated Na channels located at in salatory conduction?

myelin sheath gaps

Which disease is associated with autoimmune destruction of myelin sheathes in CNS?

multiple sclerosis

True or false: during multiple sclerosis, myelin gets turned into hardened lesion called schleroses.

True

Which of the following are the fastest, MYELINATED, AND have largest diameter?

Group A nerve fibers

Which of the following is the slowest, UNMYELINATED, has the smallest diameter

Group C nerve fibers

Which of the following has sensory and motor fibers toward skin, skeletal muscles and joints?

Group A nerve fibers

Which of the following has visceral motor and sensory that serve visceral organs?

Group B and C nerve fibers

Which of the following has an intermediate diameter and is lightly myelinated?

Group B nerve fibers

How do local anesthetics work?

blocking voltage gated Na channels

Substance P, endorphines and neuropeptide Y are examples of what? What is their speed?

Neuroactive pepties; fast transport

AcetylCholine, dopamine, nor/epinephrine, seratonin and histamine are examples of what? What speed?

Small molcule; slow transport

Where are neurotransmitters such as neuractive peptides and small molecules made?

nerve cell body or pre-synaptic endings

What type of protein is used in fast axonal transport?

kinesins (anterograde)

What effect will EPSP have on post synaptic membrane?

depolarize

What effect will IPSP have on post synaptic membrane?

hyperpolarize

Which of the following type of channels will make IPSPs and EPSPs fast?

Ligand gated ion channel

Which of the following type of channels will make IPSPs and EPSPs slow?

G-protein channel

What is an Ionotropic receptor?

channel receptor that controls flow of ions

The nature of post synaptic response is largely determined by what?

post-synaptic receptor