How nerves work

Question 1

Sensory information travels IN via

Answer 1

dorsal root

Question 2

motor information travels OUT via

Answer 2

ventral root

Question 3

afferent

Answer 3

sensory

dorsal

Question 4

efferent

Answer 4

motor

ventral

Question 5

dendrites

Answer 5

receive information

Question 6

axon hillock

Answer 6

triggers action potential

Question 7

Axon

Answer 7

sends action potential

Question 8

Axon terminals

Answer 8

release transmitter

Question 9

90% cells in the CNS are

Answer 9

glia

Question 10

Astrocytes

Answer 10

maintain the external environment for the neurones

surround blood vessels and produce the blood brain barrier

Question 11

Oligodendrocytes

Answer 11

form myelin sheaths in the CNS

Question 12

Microglia

Answer 12

phagocytic hoovers mopping up infection

Question 13

Graded potentials

Answer 13

decided when an action potential should be fired

Question 14

Resting membrane potential

Answer 14

keeps cells ready to respond

Question 15

the inside of a cell is ……….. relative to the outside

Answer 15

negative

Question 16

RMP of most cells is

Answer 16

-70 mV

Question 17

equilibrium potential

Answer 17

the membrane potential at which the electrical gradient is exactly equal and opposite to the concentration gradient

Question 18

the concentration gradient determines the

Answer 18

equilibrium potential

Question 19

Nernst equation predicts the

Answer 19

equilibrium potential

Question 20

The RMP is dominated by the resting permeability of

Answer 20

potassium (K+)

Question 21

interior of cell positively charged

Answer 21

depolarisation

Question 22

interior of cell negatively charged

Answer 22

hyperpolarisation

Question 23

the connection where one neuron modulates the activity of a target is called a

Answer 23

synapse

Question 24

contraction is triggered by AP in the

Answer 24

sarcolemma

Question 25

Can disrupt the NMJ

Answer 25

``` tetrodotoxin joro spider toxin botulinum toxin curare anticholinesterases ```

Question 26

Anatomical arrangement of synapse

Answer 26

axo-dendritic axo-somatic axo-axonal

Question 27

RMP is -70mV | threshold potential is usually

Answer 27

-55mV

Question 28

depolarisation usually reaches

Answer 28

+40 mV

Question 29

Large axons increase

Answer 29

conduction velocity you can spread Na+ channels out further - the depolarisation from one will still be big enough to get to its neighbour to reach its threshold and make its neighbour open

Question 30

Myelin

Answer 30

folds of membrane from Schwan cell or oligodendrocyte

Question 31

de-myelination diseases

Answer 31

multiple sclerosis

Question 32

de-myelination allows for the big local current to

Answer 32

decay quicker conduction fails

Question 33

Examples of graded potentials

Answer 33

Generator potentials postsynaptic potentials endplate potentials pacemaker potentials

Question 34

graded potentials are decremental therefore they are

Answer 34

only useful over short distances

Question 35

Action potential properties

Answer 35

``` encoded by frequency cannot summate threshold self-propagating depolarising voltage-gated ```

Question 36

Graded potentials

Answer 36

``` encoded by amplitude summate no threshold decremental ligand-gated ``` 'decides' is a cell will fire an action potential

Question 37

Inhibitory post synaptic potentials (IPSP)

Answer 37

hyperpolarising can open Cl- to flow out or allow more K+ in

Question 38

Excitatory post synaptic potentials (EPSP)

Answer 38

depolarising more Na gets in than K gets out

Question 39

post synaptic potentials are produced by a neurotransmitter opening of closing ion channels. therefore they are

Answer 39

ligand-gated

Question 40

action potential are produced by depolarisation of the membrane potential opening ion channels. therefore they are

Answer 40

voltage-gated ion channels