Nervous system Flashcards
parasympathetic NS on digestion
stimulates peristalsis/secretion of digestive enzymes
stimulates saliva
sympathetic/parasympathetic effect on liver
para stimulates release of bile
sympathetic conversion of glycogen to glucose
sympathetic/parasymapthetic on bladder
parasy - contracts bladder
S inhibits bladder contractiom
para/symapthetic on bronchi
para constricts bronchi
S - dilates bronchi
heart beat - para/s
para slows heartbeat
S accelerates heartbeat
para/symapthetic pupil
para contracts pupil
S dilates pupil
Action potentials - what can open/close due to stimuli, changing the potential & creating an electrical current
SPECIFIC ION CHANNELS
what is the ELECTRICAL DIFFERENCE across the membrane of the cell known as?
the RESTING POTENTIAL
what is the resting potential
electrical difference across the membrane of the cell
what type of channels are ion channels
transport channels
what are ion channels created by and where are they
created by trans-membrane proteins within the neuronal membranes
what happens when ion channels open
they allow specific ions to move through the membrane across an electrochemical concentration gradient
channels open in response to a _ which changes the permeability of the neurone membrane to Na+ & K
stimulus
Na+
sodium
K+
ptassium
4 categories of stimulus causing ion channels to open
1 voltage 2 chemicals (hormones/transmitters) 3 mechanical pressure 4 light (photoreceptors of the eye)
what do neurone at rest possess
an electrical difference/gradient across the cell membrane
what is the electrical difference/gradient across the cell membrane created by
a build up of negative ions on the inside of the cell membrane and positive ions on the other side of the cell membrane in the extra cellular fluid
in resting potential the separation of the positive and negative charges creates
potential energy
the potential energy of resting potential is approx
-70mV
cells exhibiting a membrane potential are said to be -
polarised (meaning charged)
resting potential extracellular fluid positive or negative
positive (women sign)
which 2 minerals is extracellular fluid rich in
Na+ & Cl-
Natalie & Clare!
resting potential intracellular fluid positive or negative
negative - man sign
resting potential intracellular fluid rich in
K+ Kevin & large negative ions that can’t leave cell
What tries to move back to equalise the charge
Na+ Cl-
Natalie & Claire - women always peacekeepers
the separation of the charges (polarity) of the resting potential is maintained by the
sodium-potassium pump
this separation of charges creates a potential energy of
-70mV
the formation of a nerve impulse/signal/excitation is
An action potential
an action potential is a series of events which
decrease and reverse the membrane potential, then restore it to its resting state
2 phases of action potential
1 depolarisation
2 repolarisation
the negative membrane potential (-70mV) becomes less negative, reaches zero, then becomes postitive
depolarisation
the membrane is then restored to its resting potential of -70mV
repolarisation
descrive depolarisation
the negative membrane potential (-70mv) becomes less negative, reaches zero, then becomes positive
describe repolarisation
the membrane is then restored to its resting potential of -70mV
in an action potential the only stage where the negative charge is outside and the positive charge in insides is
depolarisation
depolarisation is triggeerd by
stimulation of a nerve ending
depolarisation must reach a what in order to generate an action potential
threshold value
what physically happens in depolarisation
Na+ channels open allowing Na+ to flood into the cell
positive charge builds inside cell
what physically happens in repolarisation
K+ channels open much more slowly than Na+ channels so that as Na+ ones open, K+ open
allows K+ flood out of cell, restoring membrane potential to -70mV
period of time after depolarisation in which a nerve cannot generate another action potential because Na+ and K+ are on wring sides of the membrane
refractory period
actopn potential - what levels of Na+/K+ are maintained by sodium/potassium pumps
low level Na+
fixed level K+
action potential 2 - what opens and ovverideas Na/K pumps
sodium gates
depolaristaion/an action potential is achieved if what floods fast enough
Na+
what opens just as Na+ gates close
K+ gates
what slows/increases during repolaristaion
Na+ inflow slows
K+ outflow increases
what happens during the refractory period which resets the resting potential
Na/K pumps pump out the Na+
amino acids, peptides, monoamines are all types of
neurotransmitters
acetylcholine primary action
excitatory (inhibitory in vagus nerve)
neuro transmitter muscular contractions/cognition
acetylcholine
removal acetylcholine
degraded by enzyme acetylcholinesterase
most common neurotransmitter in the brain - excitatory
amino acid
Glutamate/aspartate
removal glutamate
reuptake
glutamate/aspartate CNS/PNS
cns
most common inhibitory neurotransmittor
Gamma-aminobutyris acid - GABA
location GABA
CNS
adrenalin produced by
tyrosine
location adrenalin
sympathetic NS
removal GABA
reuptake
removal adrenalin
reuptake/degradation by mao or comt
MAO long word
monoamine oxidase
COMT long word
catechol-oxygen-methyl transferase
exitatory/inhibatory NT in brain
regulates muscle tone, coordination/movement
dopamine
dopamine removal
reuptake/ mao/comt
seratonin produced by
tryptophan
what located in brain stem, digestive tract, platelets & pineal
seratonin
removal seratonin
reuptake or mao
Mao breaksdown which
seratonin
adrenaline
nor
dopimine
comt breaks down what
adrenalin
nor
dopamine
nitric oxide formed from
arginine
widespread, autoimmune disorder causing acute inflammation and demyelination of peripheral nerves
usually triggered 1-3 weeks after respiratory tract infection
Neuritis
guillain-barre syndrome
sudden acute progressive bilateral ascending paralysis
neuritis
cause neuritis
autoimmune
allopathic treatment neuritis
emergency - respirator, intensive care
complication neuritis
death - heart/respiratory failure
s/sx neuritis
sudden acute progressive bilateral ascending paralysis
what is ICP
cerebral oedema/inflammation
causes ICP
haemorrhage, hypoxia, infections abscesses tumours traumas/injury
s/s ICP
impaired eye movement
impaired motor function
change in speech
progressively losing consciousness
complication of icp
permanent neurological problems
seizures
death
treatment icp
critical condition intensive care
infection/inflammation of the membranes covering spinal cord
meningitis
causes meningitis
bacterial or viral infection
viral less severe
s/s meningitis
petechiae - non-blanching
photophobia
stiff neck
2 signs meningitis (names)
kernig’s
brudzinski
diagnosis meningitis
lumbar puncture
treatment meningitis
treat as medical emergency
antibiotics/antivirals
complications meningitis
brain/nerve damage
‘waiters tip’ caused by forceful pulling away of head from shoulder at childbirth
erb’s palsy
claw hand by ulnar nerve damage
klumpke’s palsy
