Muscles And Synapses L5 and L6

Question 1

There’s no direct connection between sensory neuron to muscle, the fore has to get the message across via

Answer 1

Chemical and electrical synapses

Question 2

Electrical synapses

Answer 2

• fast
• bidirectional
• communication between cytoplasm for sharing regulatory signals

Question 3

Chemical synapses include

Answer 3

Directly-gated and indirectly-gated

Question 4

Directly gated chemical synapses

Answer 4

• transmitter binds
• receptor channel opens, ions pass,
  
  • Na=EPSP
  • Cl=IPSP
• effects are fast but short lasting
• the receptor and effector are the same molecule

Question 5

Indirectly-gated chemical synapses

Answer 5

• transmitter binds
• acitvates 2nd messenger syst. (Via G-protiens, GTP activates adenylyl Cyclades which converts ATP to cAMP, the 2nd messenger)
• cAMP activates protein kinases which phosphorylate channel and causes it to open or close = change in memb. Permeability
• ions flow, depol. Or hyperpolarization.
• slow, receptor and affecter are different molecules

Question 6

Chemical synapses advantages

Answer 6

• flexible
• inhibition
• specificity: specific transmitter has specific effect on postsynaptic memb.
• complexity: type, strength, location
• plasticity: change in synaptic strucure and function (associated with learning)

Question 7

Electrical synapses advantages

Answer 7

Inflexible: great for stereotypical behaviour but hard to change

Question 8

Synaptic potentials decay with distance?

Answer 8

YES

Question 9

Do dentrites have myelination?

Answer 9

NO

Question 10

Because dentrites dont have myelin, as the current moves form its origin, the current decreases because of

Answer 10

Current leakage

Question 11

Post synaptic potential goes

AP goes

Answer 11

Both directions

One direction

Question 12

PSP summate types

Answer 12

1) subthreshold, no summation
2) temporal summation
3) spatial summation
4) spatial summation of EPSP and IPSP

Question 13

Temporal summation

Answer 13

When PSPs form single presynaptic axon overlap, they are added together. In this way, the EPSP, which are to small alone, add up to become enough for it to reach threshold and generate an AP.

Question 14

Spatial summation

Answer 14

Process by which PSPs generated in different regions of the postsynaptic neuron are added together. Summation of EPSPs initiates depol. = AP

Question 15

Spatial and temporal curation both occur

Answer 15

Simultaneously in the brain.

Question 16

Synaptic integration

Answer 16

Integration: process of summing together all the inputs into a pattern of AP in the postsynaptic cell.

Question 17

PSP summary

Answer 17

• graded
• slower
• occur in dentrites and soma
• passive conduction (over short distances)

Question 18

PSP function

Answer 18

Change pot. Of postsynaptic neuron, moving it closer (EPSP) or further (IPSP) form threshold. APs are triggered when summation depolarizes the memb to threshold.

Question 19

Ap summary

Answer 19

• all of none
• faster
• initiated at axon hillock, transmit to synaptic terminal
• active conduction (long distance transmission)

Question 20

AP function

Answer 20

If summation at axon hillock decides that neuron will fire an AP, the AP is conducted to the terminal where it causes a PSP in the postsynaptic neuron.