Lecture 23 Electrical Signals

Front 1

sensory neuron

Back 1

A nerve cell that carries signals from sensory receptors to the central nervous system.

Front 2

nerve

Back 2

A long, tough strand of nervous tissue typically containing thousands of axons wrapped in connective tissue; carries impulses between the central nervous system and some other part of the body.

Front 3

central nervous system (CNS)

Back 3

The brain and spinal cord of vertebrate animals.

Front 4

interneuron

Back 4

A neuron that passes signals from one neuron to another.

Front 5

motor neuron

Back 5

A nerve cell that carries signals from the central nervous system (brain and spinal cord) to an effector, such as a muscle or gland

Front 6

Peripheral nervous system PNS

Back 6

All the components of the nervous system that are outside the central nervous system (the brain and spinal cord). Includes the somatic nervous system and the autonomic nervous system.

Front 7

Reflex

Back 7

a direct response to a signal without integration by the brain.

Front 8

All homeostatic responses involve?

Back 8

1.) Sensor that detects the change
2.) Integrator that processes information about change
3.)Effector that diminish the impact of change

Front 9

three parts of a neuron?

Back 9

Dendrites- process information
cell body- integrates signals and outgoing signals
Axom- passes electrical signals

Front 10

What is the function of a dendrite and an axom.

Back 10

dendrite receive information, axons pass the information to other dendrites.

Front 11

membrane potential

Back 11

A difference in electric charge across a cell membrane; a form of potential energy. Also called membrane voltage

Front 12

resting potential

Back 12

The membrane potential of a cell in its resting, or normal, state

Front 13

action potential

Back 13

A rapid, temporary change in electrical potential across a membrane, from negative to positive and back to negative.

Front 14

What are three stages of an action potential?

Back 14

1.) Deplorization- when sodium rushes in
2.) Repolarization-When pottassium rushes out
3.)Hyperpolarization- charge is a bit below or more negative than resting potential.

Front 15

voltage-gated channel

Back 15

An ion channel that opens or closes in response to changes in membrane voltage

Front 16

myelin sheath

Back 16

Multiple layers of myelin, derived from the cell membranes of certain glial cells, that is wrapped around the axon of a neuron, providing electrical insulation.

Front 17

node of Ranvier

Back 17

One of the periodic unmyelinated sections of a neuron’s axon at which an action potential can be regenerated.

Front 18

What is the importance of myelinated axons?

Back 18

Myelination is interpreted as an adaptation that makes rapid trasmission of electrical signals possible in axons that have a small diameter.

Front 19

How does action potential propogate?

Back 19

Action potentials propogate down an axon becuse inrushing sodium ions depolarize adjacent portions of the membrane.

Front 20

neurotransmitter

Back 20

A molecule that transmits electrical signals from one neuron to another or from a neuron to a muscle or gland. Examples are acetylcholine, dopamine, serotonin, and norepinephrine.

Front 21

synapse

Back 21

The interface between two neurons or between a neuron and an effector cell.

Front 22

presynaptic neuron

Back 22

A neuron that transmits signals, usually by releasing neurotransmitters, to another neuron or to an effector cell at a synapse.

Front 23

postsynaptic neuron

Back 23

A neuron that receives signals, usually via neurotransmitters, from another neuron at a synapse. Muscle and gland cells also may receive signals from presynaptic neurons.

Front 24

ligand-gated channel

Back 24

An ion channel that opens or closes in response to binding by a certain molecule. (neurotransmitter binds to a ligand gated channel causes it to open and take in ions creating depolarization and thus tranducing a message)

Front 25

inhibitory postsynaptic potential (IPSP)

Back 25

A change in membrane potential, usually hyperpolarization, at a neuron dendrite that makes an action potential less likely

Front 26

excitatory postsynaptic potential (EPSP)

Back 26

A change in membrane potential, usually depolarization, at a neuron dendrite that makes an action potential more likely.

Front 27

General briefing on IPSPs and EPSPs

Back 27

The postsynaptic cell integrates information from hundreds or thousands of other neurons. The information arrives in the form of action potentials that produce EPSPs and IPSPs.

Front 28

afferent division

Back 28

The part of the nervous system, consisting mainly of sensory neurons, that transmits information about the internal and external environment to the central nervous system.

Front 29

efferent division

Back 29

The part of the nervous system, consisting primarily of motor neurons, that carries commands from the central nervous system to the body. a

Front 30

What is the current consensus on learning?

Back 30

Learning and memory involve both molecular and structural changes in synapses. Further, most researchers now agree that at least some aspects of long term memory involve changes in gene expression.