Neurophysiology, Neurotransmitters and N.S. (Chap 4)

Question 1

Neuron:

• def
• parts

Answer 1

• covered in mem. + filled w/ cytoplasm + analyze/transmit info
• Glia Cells +Cell body/stoma

Question 2

Neuron mechanisms

Answer 2

• resting potential: relative difference b/n charge on the inside and outside of the cell
  a. ) relative potential
  b. ) outside
• all-or-none law
• • nondecremental due to saltatory conduction

Question 3

Factors that affect resting potential

Answer 3

1. ) Diffusion: [gradient] dependent
2. ) Electrostatic charge: -ion attract out + +ion “” inside
3. ) Differential Permeability : ionophores/ion channel (non gated: specialized ions @ particular rate can enter)
4. )Active Transport/ion pumps: P-Na pump: 2K+ in + 3Na+

Question 4

Stimulating Axon (Action Potential )

Answer 4

1. ) depolarize threshold: voltage gate open and Na enters
2. ) Influx of Na trigger K channel and K leaves
3. ) Na channel close (refractory)
4. ) efflux K continues = repolarization phase
5. ) K channel close
6. )Na and K diffuse to reach -70mV

Question 5

Glia vs. Stoma cells

Answer 5

• support N and removes waste
  vs
  -dendrite receive chem message
• axon-axon transmit electron messages( Action pot)

Question 6

Stimulating Dendrite+ Cell body

Answer 6

• Postsynaptic potential/grade= decremental
• -> ion flow
• EPSP (Na open and cell depolarize) vs IPSP (Cl ion channel open )
• Temporal VS. Spatial

Question 7

Action Potential

Answer 7

• greater depolarizing= faster AP

Question 8

Synapse

-action parts

Answer 8

• Neuromodulators: affects NT effect
• Receptors: protein with NT binding site
• Ionotropic receptors:binging site @ channel( incrase or decrease Resting Pot)
• Metabolic “: attach to G-protein–> EPSP or IPSP or Enzyme –> 2nd messenger
• Second messenger: effect ion channel on cell side == long lasting

Question 9

Presynaptic Effects of NT

Answer 9

• autoreceptors: metabotropic cell sends feedback on # of NT released+adjust NT production
• hetereceptors: m. cell respond to chem postsynaptic when depolarized (retrograde signalling)

Question 10

Terminating Synaptic Action

Answer 10

a. ) Reuptake via transport protein

b. ) Enzymatic degradation/deactivation into precussors

Question 11

NS:breakdownn

Answer 11

-nuclei+grey matter+ganglia
vs
-tracts+white matter+ nerves

Question 12

NS subsystems

Answer 12

a.) Somantic ->signals FROM environment /motor nerve
b.)Autonomic -> internal info (blood pressure ect)
I.)Parasympathetic:rest+digest
II.)Sympathetic:fight or flight