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Flashcards in cells of the neuro system Deck (24)
1

receive inputs from other neurones and convey graded electrical signals passively to the soma

dendrites

2

synthetic and metabolic centre. Contains the nucleus, ribosomes, mitochondria and endoplasmic reticulum

cell body (soma)

3

site of initiation of the ‘all or none’ action potential?

axon hillock

4

conducts output signals as action potentials to other neurones (or other cells). Mediates transport of materials between the soma and presynaptic terminal (anterograde direction) and vice versa ?

axon

5

point of chemical (usually) communication between neurones (or other cells)

synapse

6

when a neurone is depolarising, what electrolyte comes in ?

Na

7

during depolarisation which electrolyte leaves neurone?

k

8

why do passive signals not spread far from their site of origin?

nerve cell membrane is leaky

9

what can you do to increase passive current spread?

increase axon diameter, adding more myelin sheath

10

which cells add insulating material (myelin sheath) in the PNS and CNS?

oligodendrocytes in CNS and schwann cells in PNS

11

difference in conduction between myelinated axons and non myelinated?

much faster in myelinated

12

action potential jumps from one node of ? to the next

ranvier

13

Types of synapse (2)?

excitatory,inhibitory

14

In the CNS, what is the transmitter in an excitatory synapse?

glutamate (glutes)

15

what are the major amino acid neurotransmitters in the CNS?

GABA, glutamate and glycine

16

common neurotransmitters in the inhibitory synapse?

GABA and glycine (GABA exhibit excitement)

17

what kind of response does glutamate generate?

local, graded, excitatory (depolarizing) response: the excitatory postsynaptic potential (e.p.s.p.)

18

WHAT KIND OF RESPONSE DOES GABA AND GLYCINE GENERATE?

a local, graded, inhibitory (hyperpolarizing) response: the inhibitory postsynaptic potential (i.p.s.p.)

19

why do some cells have net excitation and some net inhibition?

many inputs converge upon a neurone to determine its output

20

what are glycine and glutamate?

amino acids

21

where is GABA synthesised?

in the neurones that release it

22

Enzymes are synthesized in the cell body and are transported to the presynaptic terminal by ?

axoplasmic transport

23

what mediates synthesis within the cytoplasm of neurotransmitter from precursor substances?

enzymes

24

Synthesis of precursor peptide by ?

ribosomes