Synapse

Question 1

Definition of synapse

Answer 1

Junction b/w 2 neurons through which nerve impulses passes from one neuron to other neuron
- it is not an anatomical continuation
- but physiological continuity b/w 2 neurons

Question 2

Classification of synapse
1) anatomical classification 3 types
Depending upon “ Ending of axon “

Answer 2

1) axoaxonic synapse - axon terminates on axon of other neuron
2) axodendritic synapse - axon terminates on dendrite of another one
3) axon somatic synapse - axon of one neuron end on soma of another neuron

Question 3

Classification of synapse
2) functional classification 2 types On “ mode of impulse transmission “
(a) electrical synapse -
(b) chemical synapse

Answer 3

1) electrical synapse -
~ Junction present - gap junction
~ Direct exchange of ions b/w pre, post synaptic neurons
~ synaptic delay is less
~ impulses transmission both sides
~ occurs in cardiac muscle, smooth muscles of intestine, lens of eye

Question 4

Chemical synapse

Answer 4

Caused by jn b/w nerve - muscle fibre , signals are transmitted by release of chemical neurotransmitter ie, ach
- no continuity becoz of synaptic cleft
- action potential reaches presynaptic terminal cause releases of ach from vesicles, so potential develops

Question 5

Pre synaptic membrane
axon terminal,
Synaptic cleft
Post synaptic membrane
all these mainly consists of ?

Answer 5

Pre synaptic axon terminal - mitochondria ~ synthesise ach

synaptic vesicles ~ store ach
# Synaptic cleft - basal lamina secrets “cholinesterase” destroy ach
# post synaptic member have receptor

Question 6

Functions of synapse
Types
# Excitatory function

Answer 6

To transmit action potential from one neuron to another,
Types : excitatory & inhibitory function
# Excitatory function is same as NMJ
Potential-excitatory post synaptic EPSP
It is non propagated
Not obey all or none law

Question 7

Functions of synapse
Types : inhibitory function 5 ty

Answer 7

1) post synaptic / direct inhibition
2) pre synaptic / indirect inhibition
3) -ve feed back/renshaw cell inhibition
4) feed forward inhibition
5) reciprocal inhibition

Question 8

Properties of synapse5

Answer 8

1) one way conduction
2) synaptic delay
3) fatigue due to continuous activity
4) summation
Spatial , temporal summation
5) electrical property

Question 9

Summation means

Answer 9

Fusion or aggregation of many similar impulses becoz single impulse can’t produce any response
- fusion of ⬆️in EPSP cause summation
- when many pre synaptic terminals are stimulated, many EPSPs develop
Or single pre synaptic terminal is stimulated many times

Question 10

Types of summation
a) spatial -many post synaptic terminal are stimulated simultaneously

b) temporal - one pre synaptic terminal stimulated repeatedly

Answer 10

Spatial su - fusion of all EPSP allow to reach threshold for Action potential IPSP prevent action potential
Temporal - fusion of all EPSP on same pre synaptic terminal