560 Exam 1: Healthy Nervous System

Front 1

What are the different Glial cells

Back 1

- astrocytes
- oligodendrocytes/schwann cells
- microglia

Front 2

what are the glia cells responsible for

Back 2

protection/support and maintaing the nervous system

Front 3

what are the jobs of the astrocytes

Back 3

1) communicate with neurons via calcium diffusion through gap junctions
2) maintain normal nueornal signaling environment by scavenging inos
3) end feet connect neurons to capillaries regulating blood flow with neuron activity

Front 4

why is it important to know that astrocytes communicate via gap junctions

Back 4

tells us they don't have synapses so cannot send action potentials, rather they comminucate through diffusion

Front 5

what is the difference between oligodendrocytes and schwann cells

Back 5

oligodendrocytes = CNS
schwann cells = PNS

Front 6

what is the functino of the oligodendrocytes/schwann cells

Back 6

responsible for myelinating the nerve

Front 7

what is the function of the microglia

Back 7

phagocytes (in the CNS!) responsible for the inflammatory process in the CNS.... maintain clean neural environment

Front 8

what is the PRIMARY function of a neuron

Back 8

communcation in the nervous system

Front 9

what does the cell body contain

Back 9

the cell organelles

Front 10

where do axons terminate

Back 10

on the cell body

Front 11

what is the function of the dendrites

Back 11

branced projections conducting signals received from the periphery and taking them to the cell body

Front 12

what are dendritic spines

Back 12

protrusion sites of specific synapses.... every bud - source of synapse from another neuron

Front 13

what is the function of the axons

Back 13

projection of the nerve cell that conducts the signal away from the cell body

Front 14

what are boutons and their function

Back 14

axon terminals that allows one neuron to synapse on many many others

Front 15

what is the function of myelin

Back 15

insulation preventing leakage of current across the axon membrane

Front 16

what are the nodes of ranvier

Back 16

gaps of myelin on the axon that allow the signal being sent to be recharged so it stays strong

Front 17

why would saltatory conduction not be possible without the nodes of ranvier

Back 17

nodes have ion channels allowing the signal to be recharged... if they didn't exist, the ion radient would diminsh as it went down the axon

Front 18

where are the neurotransmitters stored

Back 18

synaptic vesicles (just pouches containing the neurotransmitters)

Front 19

how are neurotransmitters released

Back 19

depolarization triggers their release into the synaptic cleft

Front 20

what happens at the synaptic cleft

Back 20

neurotransmitter gets released and is picked up by another receptor so that it can alter some end organ

Front 21

what is a synapse

Back 21

the junction between axon terminals and the receiving cell

Front 22

what is the resting state of a neuron

Back 22

steady state electrical charge across the cell membrane -70

Front 23

what maintains the resting state of a neuron

Back 23

- Na+/K+ pump
- passive diffusion
- large anions trapped inside the neurons

Front 24

what creates the electrochemical gradient of a neuron

Back 24

ions (Na+, K+, Cl-)

Front 25

what are ion channels

Back 25

pore-forming proteins that control the voltage gradient across the cell membrane

Front 26

what is the difference between a voltage-gated ion channel and a ligand-gated channel

Back 26

- voltage-gated opens and closes in response to membrane potential changes
- ligand-gated open and close in response to specific types of molecules (neurotransmitters)

Front 27

what type of ion channel underlys the nerve impulses

Back 27

voltage-gated channels (they send impulses down the nerve axons when open!)

Front 28

what is depolarization

Back 28

the cell becomes less negatively charged causing the voltage-gated Na+ channels to open

Front 29

what is an action potential

Back 29

when threshold level of depolarization is achieved, a brief, large depolarization is generated along the length of the axon

Front 30

an action potential is a ___ or____ meaining that it fires all the way and is very strong every time

Back 30

all or none phenomenon (always the same!)

Front 31

what is repolarization

Back 31

returning to baseline

Front 32

what is repolarization dependent upon

Back 32

K+ channels opening

Front 33

what is hyperpolarization

Back 33

the membrane potential has gone too far below its potential making it less excitable

Front 34

if a neuron is hyperpolarized it has an ______ effect, and a ____ charge

Back 34

hyperpolarized has inhibitory effect.... with a more negative charge

Front 35

if a neuron is depolarized it has an _______ effect, and has a ______ charge

Back 35

depolarized has excitablility..... with a less negative (closer to positives) charge

Front 36

what state of the membrane potential includes the refractory period

Back 36

hyperpolarization

Front 37

what is modulation

Back 37

small gradual changes in membrane potential that last longer

Front 38

what is spatial summation

Back 38

increased amount of potentials

Front 39

what is temporal summation

Back 39

effects timing of potentials

Front 40

what are the chemical compounds that convey info among neurons

Back 40

neurotransmitters and neuromodulators

Front 41

characteristics of neurotransmitter

Back 41

released right into the synapse.... very quick response

Front 42

characteristics of neuromodulator

Back 42

released into the extracellular fluid .... longer response

Front 43

what is the job of either a neurotransmitter or neuromodulator

Back 43

alter the membrane potential on a target membrane... either making it more (+) or more (-)

Front 44

what are the amino acids

Back 44

GABA (inhibitory)
Glutamate (excitatory)
Glycine (inhibitory)

Front 45

what is the role of GABA

Back 45

INHIBITORY
- binds with Rc opening Cl- channels resulting in hyperpolarization of postsynaptic membrane and indirectly linked to ion channels

Front 46

what is the role of Glutamate

Back 46

EXCITATORY
- activates its receptor which opens nonselective channels

Front 47

what is the important relationship between GABA and Glutamate

Back 47

released at the same time so can cancel each other out

Front 48

what is the role of Glycine

Back 48

INHIBITORY
- inhibits postsynaptic membrans in brainstem and spinal cord and prevents desensitization of NMDA Rc

Front 49

what is the role of Dopamine

Back 49

affects motor activity, motivation, and cognition

Front 50

how do antipsychotics affect dopamine

Back 50

prevent the binding of dopamine to certain receptor sites

Front 51

what is the role of NE

Back 51

important in active surveillance of surroundings by increasing attention to sensory information (fight or flight)

Front 52

what is the role of serotonins

Back 52

adjust general arousal level and supress sensory information

Front 53

Ach is released by....

Back 53

motor neurons, parasympathetic and preganglionic sympathetic neurons

Front 54

what is the role of Ach

Back 54

major role in peripheral transmission... in CNS its involved in selection of objects of attention and autonomic regulation