Neuro-Test1

Front 1

EXCITATORY neurotransmitters do what function

Back 1

EITHER depolarize or HYPOpolarize the postsynaptic neuron

Front 2

INHIBITORY neurotransmitters do what function

Back 2

HYPERpolarize the postsynaptic neuron making it more difficult to propagate an AP

Front 3

g-proteins do what

Back 3

either stimulate or inhibit adenylate cyclase to convert ATP into cyclic AMP

Front 4

what is the major INHIBITORY neurotransmitter in the brain

Back 4

GABA

Front 5

GABA does what to neurons

Back 5

HYPERpolarizes them making them less excitable

Front 6

GABAa receptors do what

Back 6

open Cl- channels

Front 7

activation of GABAa receptors is increased by what

Back 7

*bzd

*barbs

Front 8

GABAb receptors do what

Back 8

act via a second messenger to either open K+ channels or close Ca+ channels

Front 9

what is the major EXCITATORY neurotransmitter of the brain

Back 9

GLUTAMATE

Front 10

glutamate does what function

Back 10

depolarizes neurons increasing the number of AP generated

Front 11

what are the 3 major glutamate receptors

Back 11

*AMPA

*kainate

*NMDA

Front 12

AMPA and kainate receptors do what

Back 12

allow Na+ and K+ to pass through channels

Front 13

NMDA receptors are activated when

Back 13

neurons are already depolarized and are permeable to Na, K & Ca

Front 14

activation of NMDA receptors is associated with what

Back 14

*long-term changes in neuron activity

*learning

*memory

Front 15

what receptors have been associated with neuron injury after anoxia

Back 15

GLUTAMATE

Front 16

the brain consumes what amt of total o2 uptake at rest

Back 16

20%

Front 17

approx how much of the energy of cerebral metabolism is used to support the ionic gradients necessary for the electrical activity of the brain

Back 17

60%

Front 18

after each AP Na+ and Ca+ are transported how

Back 18

to the OUTSIDE of the membrane

Front 19

after each AP K+ and Cl- are transported how

Back 19

to the INSIDE of the membrane

Front 20

Name the original thirteen colonies.

Back 20

Connecticut, Delaware
Georgia,Maryland,
Massachusetts,New Hampshire,
New Jersey, New York,
North Carolina, South Carolina,
Pennsylvania, Rhode Island
Virginia

Front 21

approx what amt of energy of cerebral metabolism is used to support the normal "housekeeping" fxns of the neurons & glial cells

Back 21

40%

Front 22

the brain relies on what substrates

Back 22

*o2

*glucose

Front 23

the brain closely couples neuronal activity with what

Back 23

BLOOD FLOW

Front 24

cerebral metabolism requires mostly what type of pathway

Back 24

AEROBIC

Front 25

with sufficient o2 how many ATP molecules are produced for each glucose molecule metabolized

Back 25

38

Front 26

withOUT sufficient o2 how many ATP molecules are produced for each molecule of glucose metabolized

Back 26

2

Front 27

the carotid arteries supply what amt of blood flow to the brain

Back 27

80%

Front 28

the vertebral arteries supply what amt of blood flow to the brain

Back 28

20%

Front 29

the amt of cerebral blood flow (CBF) varies according to what

Back 29

CEREBRAL METABOLIC RATE (CMR)

Front 30

CMR is greatest where in the brain

Back 30

GRAY MATTER

Front 31

what is normal CBF

Back 31

~ 50 ml/100 g/min

Front 32

what is CBF in the GRAY matter

Back 32

~ 80 ml/100 g/min

Front 33

what is CBF in the WHITE matter

Back 33

~ 20 ml/100 g/min

Front 34

functional impairment occurs at around what CBF

Back 34

23 ml/100 g/min

Front 35

evoked potentials and synaptic transmission disappear around what CBF

Back 35

15 ml/100 g/min

Front 36

cellular integrity is lost at around what CBF

Back 36

10 ml/100 g/min

Front 37

regarding duration of ischemia what time frame and CBF is probably irreversible damage

Back 37

*longer than 2 hours

*below 12 ml/100 g/min

Front 38

what is flow metabolism coupling

Back 38

any change in CMR is rapidly matched by an appropriate change in CBF

Front 39

what borders on all cerebral vessels

Back 39

GLIAL CELLS

Front 40

what are glial cells involved in

Back 40

control of extracellular K+ concentration in their vicinity

Front 41

when neurons depolarize what happens to extracellular K+

Back 41

it INCREASES

Front 42

what is the MOST potent physiologic determination of CBF

Back 42

PaCo2

Front 43

H+ ions cause what to occur with cerebral blood vessels

Back 43

VASODILATION

Front 44

CBF reaches a new steady state within how long after a step-change in PaCo2

Back 44

~ 1 min

Front 45

CBF increases or decreases what amt for each 1 torr increase/decrease in PaCo2

Back 45

~ 1 ml/ 100 g/min

Front 46

changes in CBF r/t PaCo2 are transient and return to normal in approx how long

Back 46

6-8 hours

Front 47

when PaO2 is at what level CBF begins to increase

Back 47

below 60 torr

Front 48

when PaCo2 reaches what level hypoxemia begins to cause dramatic increases in CBF

Back 48

below 50 torr

Front 49

what is autoregulation

Back 49

maintenence of a constant CBF in the face of changes in perfusion pressure

Front 50

CBF normally remains constant at what mean arterial pressures (MAP)

Back 50

50-150

Front 51

when MAP is out of normal levels CBF becomes what

Back 51

PRESSURE DEPENDENT-relying on the CPP

Front 52

what is CPP

Back 52

MAP-ICP

Front 53

mean arterial pressures above 150 can do what

Back 53

disrupt the integrity of the blood brain barrier causing cerebral edema or hemorrhage

Front 54

mean arterial pressures below 50 can do what

Back 54

cause cerebral ischemia and reduced energy levels for cellular function

Front 55

the cerebral autoregulation curve is shifted how with CHRONIC HTN

Back 55

to the RIGHT

Front 56

complete loss of autoregulation is common with what pts

Back 56

*tumors

*AVM's

*ruptured aneurysms

*strokes

Front 57

cerebral autoregulation is controlled via what factors

Back 57

*myogenic

*metabolic

Front 58

what type of cell appears necessary for the maintanence and development of the blood brain barrier

Back 58

GLIAL cells

Front 59

what of the endothelial membranes prevent passage of POLAR molecules

Back 59

LIPID bilayer

Front 60

what type of substance passes easily through the BBB

Back 60

LIPID soluble

Front 61

water moves how across the BBB

Back 61

FREELY d/t bulk flow

Front 62

acute HYPERtonicity results in what kind of water movement in the brain

Back 62

net movement OUT of the brain

Front 63

acute HYPOtonicity causes what type of movement of water in the brain

Back 63

net movement INTO the brain

Front 64

mannitol does what in regards to the brain

Back 64

causes an increase in tonicity of the plasma causing a sustained decrease in brain water and volume

Front 65

the blood brain barrier can be disrupted by what factors

Back 65

*acute HTN *shock
*stroke *tumor
*trauma *radiation
*sz *ischemia