Lecture 8 (Action Pot Conduction)

Question 1

Action Potential Conduction

Answer 1

• Local current flow axon regions
• Depol next region -> action potential = regenerative
• Only forward: region behind = refractory
• faster for large diameter axons
• strength by frequency of signal

Question 2

Myelination

Answer 2

• myelin increase memb resis
• reduce current leak: internodes
• speeds action potential conduction

Question 3

Nodes Of Ranvier

Answer 3

• space between myelinated chunks
• where Na+ voltage gated ion channel conc

Question 4

Saltatory

Answer 4

• action potential jumps from nodes

Question 5

Demyelinating Disorder

Answer 5

• MS (Multiple Sclerosis)
  
  • Demyelination in CNS
• Guillain Barre Syndrome
  
  • Demyelination periph nervous system

Question 6

Electrical Synapses

Answer 6

• gap junctions
• linked by intercellular channel

Question 7

Chemical Synapse

Answer 7

• w/ synaptic vesicles
• action potent -> Ca++ entry -> vesicles released

Question 8

Botulinum Toxin

Answer 8

• inhibit synaptic transmission @ NM junction
• target docking protein of synaptic vesicles

Question 9

NT Limiting

Answer 9

• Specific transporters
  
  • reuptake -> axon terminal
• Acetylcholinesterase for AcH; break down NT
  
  • Cholinesterase Inhib -> prevent enzyme breakdown