nerves

Question 1

what makes myelin sheaths in PNS

Answer 1

schwann cells

Question 2

what are Glia

Answer 2

90% cells in CNS

astrocytes
oligodendrocytes
microglia
ependymal cells

Question 3

astrocyte function

Answer 3

maintain external environment of neurons

surround blood vessels and produce BBB

Question 4

Glia cells: oligodendrocytes function

Answer 4

form myelin sheaths in CNS

Question 5

Glia cells: microglia function

Answer 5

phagocytic hoovers mopping up infection

Question 6

Glia cells: ependymal function

Answer 6

produce CSF

Question 7

resting membrane potential of neurons at equilibrium

Answer 7

-70mV

Question 8

how is a membrane potential made

Answer 8

Na/K channel keeps coming and going equally

but leaky K+ channels let more out

Question 9

membrane potential equilibrium potential is made when

Answer 9

electrical gradient is equal and opposite to conc gradient

Question 10

what does a graded potential do

Answer 10

depolarises cell to threshold for action potential to happen

Question 11

properties of graded potentials

Answer 11

graded- can be big or small

only act on short distances

can excite or inhibit

can be added together to make bigger

Question 12

hyperpolarising- fast inhibition (IPSP)

Answer 12

a neurotransmitter- GABA lets Cl- in

va ionotropic receptors

Question 13

hyperpolarising- slow inhibition (IPSP)

Answer 13

G protein is triggered by a neurotransmitter and lets K+ out

by metabotropic receptor

Question 14

depolarising- fast excitation

Answer 14

neurotransmitter lets lots of Na+ in (and some K+ out)

ionotropic receptor

Question 15

depolarising- slow excitation

Answer 15

neurotransmitter triggers G protein and

blocks leaky K+ channels

metabotropic receptor

Question 16

what does the axon hillock do

Answer 16

fires the action potentials

Question 17

the closer to the axon hillock

Answer 17

the bigger the signal

Question 18

a signal with a slight time gap but same dendrite is called

Answer 18

temporal summation

Question 19

a time gap but different dendrites creates

Answer 19

spatial summation

Question 20

properties of an action potential

Answer 20

have a threshold

all or none

only encode intensity using frequency- not height

have a refectory period

self propagating

travel slowly

Question 21

why cant action potentials trigger backwards

Answer 21

the the refectory period

Question 22

neuromuscular junction 1

Answer 22

action potential in a motor neuron opens voltage gated Ca2+ channels- which helps make vesicles

to let out ACh

Question 23

neuromuscular junction 2

Answer 23

ACh binds to nicotinic receptors in muscle

ligand gated Na/K channels create a graded potential (end plate)

then voltage gated ligand channels create action potential

Question 24

how is ACh removed

Answer 24

acetylcholinesterase

Question 25

why does the neuromuscular junction have a safety factor

Answer 25

post junctional folds mean the endplate potential has a short distance to travel to the voltage gated Na+ channels

so no synaptic integration

Question 26

CNS synapses

Answer 26

multi synaptic

Question 27

PNS synapses

Answer 27

monosynaptic