Nervous System

Front 1

the peripheral nervous system

Back 1

cranial nerves
spinal nerves
ganglia

Front 2

the basic communicating structure of the nervous system

Back 2

neuron

Front 3

a collection of neuron cell bodies and their projected axons which sense and controls body functions

Back 3

brain

Front 4

the brains neuron cell bodies are in the blank, such as the cerebral cortex, basal ganglia and thalamus

Back 4

gray mater

Front 5

a collection of neuron cell bodies in the central gray matter surrounded by axonal projections in the white matter

Back 5

spinal cord

Front 6

the spinal cord connects the brain through the blank of the skull and is encircled by the bones of the vertebral colum

Back 6

foramen magnum

Front 7

blank pairs of spinal nerves emerge from the spinal cord, each serving a specifici region of the body

Back 7

31

Front 8

all nervous tissue outside the CNS (spinal nerves, cranial nerves, ganglia) make up what

Back 8

PNS

Front 9

groups of neuron cell bodies outside the CNS

Back 9

ganglia

Front 10

cranial nerves are attached to

Back 10

the brain or brain stem

Front 11

spinal nerves are attached to

Back 11

spinal cord

Front 12

true or false, cranial nerves may be sensory, motor or both

Back 12

true

Front 13

a bundle of axons

Back 13

nerve

Front 14

a propagated electrical alteration along individual axons

Back 14

action potential

Front 15

nerve impulses

Back 15

motor control signals to muscles and glands

sensory information signals

Front 16

ventral horns are mostly

Back 16

motor

Front 17

dorsal horns are mostly

Back 17

sensory

Front 18

spinal cord and spinal nerves

Back 18

intervertebral foramen of spinal cord

Front 19

cranial nerves

Back 19

12 pairs of nerves off the brain and brain steam, CN I-XII, motor, sensory or both, head and neck areas(primarily)

Front 20

The fifth nerve of cranial nerves that is primarily a sensory nerve, but it also has certain motor functions (biting, chewing, and swallowing).

Back 20

trigeminal nerve

Front 21

autonomic motor ganglia subdivisions (unconscious system)

Back 21

sympathetic ganglia and parasympathetic ganglia

Front 22

what consists of the brain and spinal cord and intergrating centers

Back 22

CNS

Front 23

connects CNS to muscles, glands and all sensory receptors

Back 23

PNS

Front 24

sensory (afferent) division and motor (efferent) division

Back 24

PNS

Front 25

motor efferent division subdivisions

Back 25

autonomic nervous system (ANS) and somatic nervous system

Front 26

somatic nervous system

Back 26

conscious and voluntary,
neurons from cutaneous and special sensory receptors to the CNS, motor neurons to skeletal muscle tissue

Front 27

a separation of charge (voltage) across the plasma membrane of excitable cells

Back 27

resting membrane potential

Front 28

momentary reversal and return of resting membrane potential

Back 28

action potential

Front 29

ion distribution ECF

Back 29

Na and Cl

Front 30

ion distribution ICF

Back 30

K+, proteins, phosphates

Front 31

sodium-potassium pump

Back 31

pumps sodium ions out of the cell, pumps potassium ion into the cell

Front 32

sodium-potasssium pump is a

Back 32

transporter

Front 33

polarized membrane is primarily due to

Back 33

selective ion diffusion and diffusion potential

Front 34

membrane ion channels have a purely blank movement of ions

Back 34

diffusion

Front 35

random movement of particles due to thermal energy

Back 35

diffusion

Front 36

resting membrane potential is primarily due to blank diffisuion

Back 36

potassium

Front 37

speed at which a molecule or ion moves through a membrane

Back 37

permeability

Front 38

sodium and potassium channels are influenced by blank gradient and blank gradient

Back 38

concentration, electrical

Front 39

ion leakage channels characteristics

Back 39

ion specific, always open, diffusion rate influenced by (concentration gradient, electrical gradient), more K+ leakage channels than Na+ leakage channels

Front 40

relative permeability of cell membrane

Back 40

K+> cl-> Na+> protein
100: 40:1:0

Front 41

if the membrane is relatively permeable to K+, wonts its high internal concentration cause it to rapidly diffuse out of the cell and equalize the concentrations

Back 41

no, it wont b/c of the electrical gradient created by selective potassium diffusion in exclussion of its anions, protein and phosphate

Front 42

Potassium diffusion potential characteristics

Back 42

concentration gradient forces, electrical gradient forces, and Na-K pump maintains concentration gradient

Front 43

Ek=?
Ena=?

Back 43

-90mv, +60mv

Front 44

magnitude of equilibrium potential for K+

Back 44

K+ gradient (ECF= 5meg/L, ICF=150meg/L), nernst equation, EqP=-60X log (ICF conc./ECF conc.), K+ EqP = -60 X log (150/5), EqP = -88.6mV
permeable ions always diffuse in a manner to bring the ICF voltage toward their equilbrium potential

Front 45

potassium Equilibrium potential

Back 45

at its equilibrium potential the concentration force is equally balanced by an opposite electrical force and there will be no net diffusion of the ion

Front 46

which equilibrium potential potential takes a relatively small amount of difference in cation/anion concentration to produce a substantial electrical gradient or membrane voltage

Back 46

potassium equilbirum potential

Front 47

resting membrane potential

Back 47

K+ diffusion
Na+ diffusion
Cl- diffusion
Na+-K+ pump
no ion equilibrium
dynamic balance

Front 48

resting membrane potential characteristics

Back 48

-70 to -90 mV potential within neurons
Na-K pump establishes conc.gradients (and small electrogenic potential, -5mV),
leakage channels allow selected ion to permeate the cell membrane
many more K+ leakage channels than Na+ leakage channels
The resting potential is the dynamic balance between these ionic movement

Front 49

why is the inside of the cell negative if the voltage is caused by potassium diffusion?

Back 49

ions exist in oppositely charged pairs, cation and anion. if potassium selectively diffuses out of the cell, it leaves its anion partner behind in the ICF.

potassium's ICF partner is usually phosphate or protein, both are impermeable. They remain within the cell and create a negative intracellular potential

Front 50

Na+ equilibrium potential
Resting membrane potential
K+ equilibrium potential

Back 50

+ 60mV, -70mV, -90mV

Front 51

momentary reversal of resting potential

Back 51

action potential

Front 52

action potential spike lasts about

Back 52

I msec

Front 53

gated ion channels

Back 53

normally closed,
open when activated

Front 54

Na+ gated ion channel opening fast or slow

K+ gated ion channels opening fast or slow

Back 54

really fast,slow

Front 55

types of gated channels

Back 55

voltage-gated channels
ligand gated channels
stress channels

Front 56

e.g of voltage gated channels

Back 56

voltage-gated Na channel
Voltage-gated K channel
opened by a decrease in ICF voltage

Front 57

action potential rise phase caused by

action potential falling phase is caused by

Back 57

influx of Na, efflux of K+

Front 58

which takes place first (absolute or relative refractory period)

Back 58

absolute

Front 59

true or false, at the resting potential, both voltage-gated Na and voltage-gated K channels are closed

Back 59

true

Front 60

true or K + voltage-gated channels

Back 60

true

Front 61

repolarization

Back 61

inactivation of voltage gated Na channels, activation of slower voltage k channels, outflow of K+, resetting of voltage gated Na channels

Front 62

during the blank phase the axon interior becomes positively charged. The voltage-gated Na channels become inactivated (closed). The voltage-gated K+ channels begin to open. the action potential peak is reached.

Back 62

reversal

Front 63

the part of the hyperpolarization phase of an action potential where the membrane falls below the normal resting potential

Back 63

after-hyperpolarization

Front 64

after-hyperpolarization

Back 64

voltage gate K+ channels slow to close, higher than normal K+ permeability, decreased membrane excitability

Front 65

how much does the concentration gradient change during an action potential

Back 65

almost zero

Front 66

conduction of speed of action potentials

Back 66

axon diameter (larger diameter, fast, small diameter, slow) and myelination

Front 67

axon classes

Back 67

A myelinated axons
B special
C non myelinated

Front 68

A, myelinated axons diameter and conduction speed

A alpha
B beta
C Gamma
A delta

Back 68

15-20micro, 70-120 m/sec
5-10 micro, 30-70 m/sec
3-6 micro, 15-30 m/sec
2-5 micro, 12-30 m/sec

Front 69

C, non-myelinated axons diameter and conduction speed

Back 69

0.5-1 micro, 0.5-2 m/sec

sharp pain axons (very discret)
non-discriminatory

Front 70

initiation of action potentials

Back 70

threshold;neurona action potentials are initiated which the inflow of sodium ions exceeds the outlfow of potassium ions enough to partially depolarize (threshold voltage) a portion of the neuronal membrane and start an all-or-nothing depolarization through opening of voltage gated sodium channels

Front 71

the initial partial depolarization is usually caused by

Back 71

the opening specific sensory receptor channels in sensory axons terminals (PNS) or the opening of ligand gated channels by neurotransmitters in the soma or dendrites of motor neurons or sensory relay neurons within the CNS. both of these mechanims produced localized graded depolarizations that may initiate action potentials

Front 72

local anesthesia blocks

Back 72

voltage gated sodium channels, and conduction of action potentials and sensory information fails to reach CNS.

Front 73

synaptic synapses have graded potential or action potentials

Back 73

graded potentials

Front 74

synapses

Back 74

chemical junctions between neurons, connect upper motor neuron to lower motor neurons, connect primary sensory neuron to secondary relay neuron

Front 75

postsynaptic synapses are
presynaptic synpases are

Back 75

chemically gated
electrical voltage signals

Front 76

sensory ganglia or skin mucous membrane or proprioception ending are

Back 76

1st order neurons

Front 77

2nd order neurons found in

Back 77

spinal cord

Front 78

most synapses occur on the blank or the cell body and produce blank postsynaptic potentials

Back 78

dendrites, graded

Front 79

true or false, graded potentials dissipates with time and distance but action potentials dont

Back 79

true

Front 80

graded postsynaptic potentials are blank, non-propagated voltage changes that decay with time and distance

Back 80

localized

Front 81

postsynaptic graded potentials are found in the

Back 81

cell body not axon,
are turned on or off

Front 82

where does an action potential begin

Back 82

axon hillock

Front 83

Excitatory post synaptic potential (EPSP)

Back 83

small depolarizing graded potential, brings postsynaptic membrane closer to threshold voltage for excitaton, chemically gated (ligand) channels; open cation selective channels, mostly Na+ entry,duration of EPSP may be 15 msec. or more

Front 84

duration of IPSP

Back 84

15 msec

Front 85

IPSP

Back 85

small hyperpolarizing graded potential, take postsynaptic membrane potential away from threshold voltage, decreases excitability, ligand gated channels open potassium or chloride selective channels,

Front 86

1000-10,000 synapses on a

Back 86

motor neuron
excitatory or inhibitory

Front 87

EPSP and IPSP amplitude postsynaptic

Back 87

I mV or less

Front 88

neuron threshold postsynaptic membrane

Back 88

15mV less negative than the resting potential at the axon hillock or node of ranvier

Front 89

EPSP and IPSP are conducted

Back 89

decrementally ( decrease in amplitude with time and distance)

Front 90

location of synapse relative to axon hillock, " trigger zone" determine

Back 90

the effectivenesse of postsynaptic responses

Front 91

many EPSP are usually required to bring about a

Back 91

postsynaptic action potential

Front 92

summation of postsynaptic graded potentials

Back 92

spatial sumation, temporal summation, combined summation

Front 93

many synaptic active at the same time

repeated synaptic actively due to a frequency of action potentials

Back 93

spatial summation, temporal summation

Front 94

combined and temporal summation, mixed summation (EPSPs and IPSPs), neuronal integration

Back 94

combined summation

Front 95

can be opened from inside or outside

Back 95

chemically gated channels

Front 96

synapse vs neuromuscular junction

Back 96

neuromuscular junction 1 for 1, does not require summation, CNS synapse require summation,

Front 97

termination of neurotransmitter response

Back 97

reuptake of transmitter, enzyme degradation (e.g acetylcholinesterase), diffuse away (into blood or glial cells)

Front 98

drug effects at synapses

Back 98

neurotransmittter synthesis
neurotransmitter release
neurotransmitter removal
receptor activation (agonists)
receptor blocker ( antagonists)

Front 99

action potentials depend on

Back 99

voltage gated channels

Front 100

partial depolarization equal

Back 100

graded potentials

Front 101

do sensory receptors have voltage gated channels

Back 101

no, no actio potentials but have graded potentials

Front 102

sensory receptors nociceptor function

Back 102

pain receptors

Front 103

sensory receptors mechanoceptors (type 1 cutaneous )

Back 103

tactile or merkel disc

Front 104

sensory receptors mechanoreceptors (type II cutaneous)

Back 104

ruffinin corpuscle

Front 105

lamellated sensory corpuscle

Back 105

pacinina corpuscle

Front 106

sensory nerves and receptors

Back 106

modified ends of sensory axons different from membrane receptors

Front 107

first order sensory neuron with free nerve ending

first-order sensory neuron with encapsulated nerve endings

sensory receptor synapses with first order sensory neuron

Back 107

cold stimulus, pressure stimulus,Guastory (taste) receptor

Front 108

there are usually how many neurons in a sensory pathway

Back 108

three

Front 109

specific modality and specific location sensory coding

Back 109

labeled line theory

Front 110

qualities or characteristics we use to define a particular stimulus;pain, pressure, itch, determined primarily in the sensory area of th cerebral cortex

Back 110

modality

Front 111

lowest threshold stimulus, rececptors are somewhat specific

Back 111

adequate stimulus

Front 112

stimulus intensity

Back 112

number of sensory receptors activated

Front 113

sensory systems

Back 113

somatic senses and special senses

Front 114

somatic senses modalities

Back 114

touch, pressure, vibration, temperature, pain, proprioception

Front 115

special senses modalities

Back 115

taste, hearing, vision, smell, equilibrium

Front 116

each sensory receptor has its own type of blank stimulus to which it has a low threshold

Back 116

adequate

Front 117

stimulus characteristics

Back 117

adaptation, pain, proprioception

Front 118

proprioception

Back 118

body sense (joing receptors, angulation, muscle sense, length and tension)

Front 119

sharp pain
dull pain (blocked by local anesthetic)
referred pain

Back 119

A delta axons, C axons, heart atttack,

Front 120

slow adaptiotion
Rapid adaptation

Back 120

tonic receptors, phasic receptors, rate

Front 121

sensory pathways

Back 121

sensory receptor to CNS, postcentral gyrus, opposite side, labeled line (modality and body location)

Front 122

what determines modality

Back 122

cortex

Front 123

three neuron pathway to primariy sensory cortex

Back 123

1 sensory ganglion, 2 spinal nucleus or brain stem, cross over, 3 thalamus, somatosensory cortex, postcentral gyrus

Front 124

dorsal columns

Back 124

sensory pathway, discrete tactile sensations, proprioception, second order neuron in medulla,crossover

Front 125

lowest part of the brain stem

Back 125

medulla

Front 126

spinothalamic tract

Back 126

sensory pathway, pain, temp, second order neuron in spinal cord at level of entry,always cross over

Front 127

where are the 2 locations of the peripheral nerves axon cell bodies

Back 127

1 the dorsal root ganglion (sensory, afferent )
2 the CNS (motor,efferents)

Front 128

Head and Neck sensory

Back 128

opthalmic (V1), maxillary (V2), mandibular (V3)

Front 129

sensory pathways of the face

Back 129

trigeminal nerve and ganglion, trigeminal nucleus, thalamus, facial region of sensory cortex,

Front 130

somatosensory cortex

Back 130

postcentral gyrus, specific topographic map of body (specific modality or specific body location), distorted area representation (depends upon sensory receptor density)

Front 131

Post central gyrus location

Back 131

parietal lobe

Front 132

dermatome

Back 132

the area of skin innervated by one spinal or cranial nerve

Front 133

where in the sensory pathways do local anesthetics usually work

Back 133

block voltage gated sodium channels, they dont block the initiation but the projection of action potentials

Front 134

the quality given to a particular stimulus, determined in the sensory cortex

Back 134

modality

Front 135

adequate stimulus

Back 135

the type of stimulus to which the sensory receptor has its lowest threshold

Front 136

adapation

Back 136

loss of receptor response with continued stimulus application

Front 137

perception

Back 137

the conscious awareness of sensation by the cerebral cortex, lost with anesthesia

Front 138

motor unit

Back 138

lower motor neuron and all the muscle fibers it innervates, all or none

Front 139

motor pathways

Back 139

upper motor neuron (precentral gyrus) and lower motor neuron (brainstem or spinal cord, to muscle motor unit)

Front 140

intraoral innervation

Back 140

maxillary division of trigeminal (maxillary teeth and palate) and mandibular division of trigeminal (mandibular teeth, tongue and floor of mouth)

Front 141

corticobulbar path

Back 141

to head muscles, lower motor neuron in brainstem nuclei of CNS.
Trigeminal, mandibular nerve only (V3)

Front 142

corticospinal path

Back 142

to body muscles, lower motor neurons in the ventral horn of spinal cord,

Front 143

somatomotor cortex

Back 143

precentral gyrus, unequal distribution of body areas, larger cortical areas devoted to muscles for discrete motor activity, not strength (fingers vs legs)

Front 144

somatic motor pathways

Back 144

1.primary motor cortex; precentral gyrus
two neuron pathway;upper motor neuron, lower motor neuron, alpha motor, opposite side, to skeletal muscles.
2. corticospinal pathway ( doesnt go through the thalamus)