04 JUNE 2019 Flashcards
End of Chapter two start of chapter five
circle of willis (fx)
connects all of the cerebral arteries in the brain
connects left to right - front to back
nine arteries connecting post. to the internal carotids
to get COLLATERAL CIRCULATION
the anterior cerebrallar A gives blood to where?
longitudinal fissure and some middle cortex
the middle cerebrallar A gives blood to where?
DEEP in the brain - temporal and parietal lobes
- then heads lateral
the internal cartoid feeds into what arteries?
ant and mid cerebellar A
the posterior communicating A connects
the internal cartoid A to the post cerebrallar A
how many choirodal A are there?
two
where does the choirodal A extend off
1 - post cerebellar A
2 - middle cerebellar A
what does the choirodal A give to :
1 - thalamus
2 - basal ganglia
3 - leaky capillaries to ventricles for CSF
what does the striate A supply?
basil ganglia
how many dural sinuses are there?
3
a dural sinus is what?
a pocket in the dura
where is the superior saggittal sinus
along the longitudinal fissure
where is the inferior sagittal sinus?
the floor of the longitudinal fissure
- when the inner layer of dura doubles back down on itself
where is the transverse sinus?
starts at the center back
how many transverse sinus are there?
2
list all three dural sinuses
superior sagittal sinus
inferior sagittal sinus
transverse sinus
fx of the transverse sinus?
dumps blood into the jugular vein
what are the two main cells:
1- nerve cells
2- glial cells: support cells
nerve connections are _______ which means that they can ________-
plastic which means they can weaken or strengthen
list the four components of the neuron:
1- soma
2- dendrite
3- axon
4 -axon hillock
soma fx
cell body where the nuclei and all the working parts are
dendrite fx
receives messages
axon fx
pushes messages and sends them out to other neurons
axon hillox fx
the most proximal part of the nerve where the electrical signal is created then goes down
do neurons touch each other?
NO
so what is between each neuron?
synaptic cleft
list the three structure of what is between a neuron
1 - presynaptic terminal
2 - synaptic cleft
3 - post synaptic membrane
what do messages do to get to another neuron
DIFFUSE
what four things do neurons do?
1 - receive
2 - intergrate
3 - transmit
4 - transfer
how many fx does a neuron have?
4
anterograde
forward direction in usual direction
- sends the message down the axon to get transmitted back
- sends down the ski lift
retrograde
backward reverse direction
- sends the empty chair lift back to the soma
how many types of neurons are there?
4
list the four types of neurons:
1 - bipolar
2- pseudounipolar
3 - multipolar
4 - interneuron
what is a bipolar neuron?
1 dendrtic trunk
1 axonic trunk
where are bipolar neurons found?
only in some places like retina of the eye
not very common
what is a pseudounipolar neuron
1 branch that seems like there is two but only 1
- two parts that act like dendrites and axons
- 1 peripheral branch
- 1 central branch
where are pseudounipolor neurons found?
really only in one part of the brain : sensosomatotic fxs
what is a multipolar neuron?
many muliptle big dendrites branches
one axonic trunk
where are mulipolar neurons found?
all over
most common neuron in the body
what is an interneuron
4 / mulitple dendritic trunks
1 axon trunk
(so looks like a multipolar neuron)
but SMALL
where are interneurons found?
inbetween an axon and dendrite of two different neurons
fx of interneuron:
to deliver and can modify messages
what are the four types of membrane
1 - leak (non-gated) channels
2 - voltage gated
3 - modality gated
4 - ligand-gated
what is a leak (non-gated) channel
it is free open all the time things just flow in and out
- its got its legs WIDE open (whore)
molecules “leak” through
what is a voltage -gated channel
molecules can only pass through with a voltage change
- naturally the inside is neg and the outside pos
- so that needs to change
change in the charge of the ion or membrane
what is a ligand gated channel
the channel only opens if a ligand = protien = neurotransmitter opens the door
what is a modality gated channel
the channel opens up with a modality of mechanical property (like heat)
polarized means
to be different
what are the 3 electrical properties: (potentials)
- resting
- local
- action
what is a resting potential?
when there is a difference in potentials
inside is negative
outside is postive
- what naturally every cell has
what two things do sinuses have?
blood AND CSF
what does the falx cerebri do?
draws the ventricles (water balloon) down to protect the two hemispheres
