Cell M2: Module 2

Question 1

junctions between neurons permitting direct passive flow of electrical current

Answer 1

electrical synapsis

Question 2

junctions between nuerons that communicaate via the secretion of NT

Answer 2

chemical synapses

Question 3

gap juntion channel is made of ________ which is made of __________

Answer 3

2 hemichannels made of 6 connexins each and a channel pore

Question 4

are electrical synapses selectuve?

Answer 4

no nonselective and channel pore is very large

Question 5

why electrical transmission over chemical in some instances

Answer 5

veyr fast
usually bidirectional
- good for flight responses or synchronation of neuron activity - interneurons

Question 6

are electrical synapse - gap junctions- usually closed of open?

Answer 6

clsoed and only few open at one time for easy regulation

Question 7

what can happen to gap junctino channels

Answer 7

they can be phosphporylate

Question 8

what percent of synapses in brain are chemical

Answer 8

99%

Question 9

common structural features of a chemcial synapse

Answer 9

presynaptic bouton
synaptic vesicles
active xone
synaptic cleft
postsynaptic specialization

Question 10

zone at presynaptic membrane where eocytosis of NT through vesicles occue

Answer 10

active zone

Question 11

post synaptic specialization

Answer 11

contains |NT receptos and signalling/ scaffolding protiesn

Question 12

assymmertrical synapses are mostly

Answer 12

excitatory

Question 13

ssymetrical synapses are mostly

Answer 13

inhibitory

Question 14

symmetrical synapses –.

presynaptic active zone thickness ______ postysnaptive specialzation thickness

Answer 14

equals

Question 15

asymmertrical synapses

presynaptic active zone thickness ______ postysnaptive specialzation thickness

Answer 15

presynaptic active zone thickness < postysnaptive specialzation thickness

Question 16

____ vesicles contain amino acid NT and acetlycholine

Answer 16

small synaptic vesicales with little electron density

Question 17

___ vesicles containe monoamines

Answer 17

small electron dense SV

Question 18

_____ vesicles contain peptide neurotransmitters, large

Answer 18

large dense-core vesicles

Question 19

excitatory synapses on dendritic spines

Answer 19

axospinous synapses

Question 20

excitatory or inhibitory synapses on dendritic shafters

Answer 20

axodendritic synapses

Question 21

mostly inhibitory synsapses onto cell bodies

Answer 21

axosomatoc synapses

Question 22

inhibitory synapses on other axons and presynaptic boutons

Answer 22

axo-axonic synapsis

Question 23

inhibitory, bidirection, synapses between dendrites

Answer 23

dendro-dendritic synapses

Question 24

excitatory sunapses between a neuron and a muscle cell

Answer 24

neuromuscular junctions

Question 25

reverse potention = ____ when there is no net chagre transfer across membrane

Answer 25

membrane potential

Question 26

if Vm < Erev the flux of cations, or current is

Answer 26

inward flux of cations; inward currents; outward flux of anions

Question 27

if Vm> Erev the flux of cations or current is

Answer 27

outward; outward curret; influx of anions

Question 28

when a synapse is acticates and ligand ion channels open membrane potenitl __________________________

Answer 28

ALWays becomes more similar to reverse potential of an ion channel

Question 29

post synaptic currents and potentials are _____ if reversal potential is more positive than the action potential threshold

Answer 29

excitatory

Question 30

post synaptic currents and potentials are _____ if reverse potential is more negative than the action potential threshold

Answer 30

inhibitory

Question 31

spatial summation:

Answer 31

when multiples single synapses are a tivated at the same time to electicit an eaction potential

Question 32

if post synaptic potentials derived from sungle synapses are inhibitory it contribues to _____

Answer 32

the prevention of action potential initiation

Question 33

mechanism to amplify excitator input at distance synapses?

Answer 33

voltage gated conductances in denrites can amplify local Excitaoty post synapsetuc potentials with denritie spikes