week 6 workshop Flashcards
How created dualism?
- renee decorates
the body and the spirit, two seperate things.
this dominated for 400 years. this continued into the late twentieth century.
what is a PET scan?
- used to understand disorders of consciousness
- involves injecting a low half life isotope into the brain, then we can track where this isotope is being activated.
(tracks consumption of glucose sugars in the brain).
what is the unerving state of kim jong nam
-air apparent
bit of a party boy.
gave up being the next air.
embarresed the family.
he was killed by a hankerchief with VX that killed him (nerve agent).
How did Kim kong nam die?
via VX requires 10 mgs to be absorbed.
it only takes 15-20 minutes for him to be killed.
How did VX kill him?
we have to understand the interconnecting relationship of the body and the mind
Define Neurons
- specialise in the transfer info within the nervopius system.
sensory neurons- transmit info from sensory receptors in the body to the brain
motor neurons - transmit commands from the brain to the muscles and glands of the body
interneurons - interconnect neurons into a complex network, most common
how do neurons work?
at rest neuron is polarised: there is negative electric charge inside the cell memebrane and a positive charge outside. The difference is known as the resting potential. when a neuron is stimulted by another, its cell membrane is either depolarised (increasing firing potential) or hyperpolarised (decreasing firing potential) -termed graded potentials. if the cell reaches its firing threshold the neuron will fire (action potential).
what is the membrane of the neuron?
seperates charged neurons.
- sodium ions are concentrated outside the cell membrane.
- there is more potassium ions inside the cell.
at rest: cell is negatively charged relative to the outside.
this is because there are more postively charged neurons outside the cell membrane, lose charge cell will die.
what happens when you stimulate the nerve membrane?
- open ion channels (holes)
ion s will move in or out of cell, depending on the channel that is opened.
depolarisation: - sodium channels open first, allowing sodium to flow into the neuron do the concentration gradient. this then makes the cell less neagtive on the inside.
what happens when it become less negative?
- more channels opne, more sodium in the cell, cell will become postively charged.
allows potassium to flow out. down electrical gradient. this will change charge and make the cell is starting to become negative. ‘pumps’ come into gear and the cell tries to go back to original state.
what generates an action potential?
??
depolarisation will stimulate an action potential, this rush of particles into the cell.
this passes along the axon like a ripple.
a myeline sheath around the axon acts as an insulator and speeds up conduction of the action potential.
different between gray and white matter in the brain?
gray matter is neuron cell bodies
white matter is axons.
discuss synaptic communication
axon ends in series of fine branches call button.
which connects into other neuronal membranes.
these contain tiny vesicles of a signal chemical called a neurotransmitter.
when action potential reaches these buttons, causes vesicle fuse to cell membrane and then rupture releasing neurotransmitter into the gap between two neurons. this gap is call the synaptic cleft.
then it attaches to postsynaptic neurons - causing channels in the cell membrane to open like a key in a door. letting sodium ions in triggering an action potential in the post synaptic cell.
Neurotransmitters molecules will diffused out of cleft or degraded by enzymes, this stops the depolarisation of the post synaptic cleft.
what is neurotransmitter removal?
- reuptake almost immediately neurotransmitter moleciles are drawn back into the presynaptic button
enzymatic degradation: ensymes degrade (break apart) the neurotransmitter so that it cannot function.
summarise
all brain function comes from synaptic communication.
many disorders will occur from ONE of these steps or more.
for example Parkinson’s and the loss of the dopamine neurotransmitter.
most psychiatric drugs are focused on this process
