Biology 2121 – Pre-Lecture Questions – Chapter 11 (Part II) – Neurophysiology
1. What is a graded potential? How does it differ from an action potential?
2. Complete the table below concerning graded potentials
Alternate Names for
Graded Potentials
Why is it referred to as this name?
1. Receptor or Generator
Potential
2. Postsynaptic Potential
3. What is Hyper-polarization? _____________________________________________________________________
4. Complete the table below concerning the production of Action Potentials.
Event
Describe what happens to the sodium
and potassium gates and the flow of
these ions
Estimated mV during this
period
Polarized or
Resting State
All voltage gate channels are closed; only
leakage occurs of both ions.
-70 mV
Depolarization
Phase
Repolarization
Phase
Hyperpolarization
Phase
5. After re-polarization, the ___________________ pump returns ion redistribution to its normal state.
6. What is threshold stimuli? _____________________________________________________________________________
7. Action potentials are said to be all or nothing events. Why? __________________________________________________
8. Compare the absolute refractory period to the relative refractory period.
9. Complete the table concerning conduction velocity of neurons below:
Characteristics
Describe conduction velocity (fast, slow, actual velocity, etc.)
1. Axon has a wide
diameter
2. Axon diameter is
narrow
3. Axon is heavily
myelinated
4. Axon is unmyelinated
10. Complete the table based on the axon diameter, mylenation and type of neuron.
Classification Examples
Diameter
Myelination
Velocity
Group A
Fibers
Large diameters
Heavy
150 m/s
Somatic sensory and
motor fibers
Group B
Fibers
Group C
Fibers
11. Distinguish between a presynaptic and postsynaptic neuron. ________________________________________________________
12. Distinguish between a chemical and electrical synapse below:
13. Complete the tables concerning the following neurotransmitters
Chemical
Neurotransmitter
Classification
1. Acetylcholine
Acetylcholine
Functional
Class
Excitatory –
always with
skeletal
muscles
Inhibitory or
Excitatory with
Smooth
Muscles
Site –
Secreted
From
CNS – Brain
and Brain Stem
Comments
Acetylcholinesterase enzyme that
breaks down ACh is blocked by nerve
gas
PNS –
Neuromuscular The release of this enzyme is also
Junctions
inhibited by the bacteria which
produces the botulinum toxin
CNS only 2. Histamine
3. ATP
14. Complete the table concerning Neural Integration below:
Question
Description
1. What is a
neuronal pool?
2. What is a
diverging circuit
3. What is a
converging
circuit?
4. What is a
reverberating
circuit?
5. What is a
parallel afterdischarge
circuit?
15. Compare serial process and parallel processing. Which are associated with spinal reflexes?
Example (if
applicable)