Chapter 8 - Neurons

Question 1

Map the organization of the nervous system in detail.

Question 2

Draw and describe the parts of a neuron and give their functions.

Answer 2

• cell body –> control center
• dendrites –> receive incoming signals
• axons –> carry outgoing signals

Question 3

Describe the parts of a synapse and their functions.

Question 4

Name the types and functions of glial cells.

Answer 4

• ependymal cells –> create barriers between compartments + source of neural stem cells
• astrocytes –> source of neural stem cells + …
• microglia –> scavengers
• oligodendrocytes –> form myelin sheaths in CNS
• Schwann cells –> form myelin sheaths in PNS + secrete neurotrophic factors
• satellite cells –> support cell bodies in PNS

Question 5

Explain in words how the Goldman-Hodgkin-Katz equation relates to the membrane potential of a cell.

Answer 5

equation calculates the membrane potential that results from the contribution of all ions that can cross the membrane

(membrane potential influenced by concentration gradient of ions + membrane permeability to those ions)

Question 6

Compare and contrast graded potentials and action potentials.

Answer 6

graded potentials:
- type of signal: input signal
- occurs where: dendrites + cell bodies
- gated ion channels:
- ions involved:
- signal strength:
- signal strength:
- what initiates signals:

action potentials:
- type of signal: regenerating conduction signal
- occurs where: trigger zone thru axons
- gated ion channels:
- ions involved:
- signal strength:
- type of signal:
- signal strength:
- what initiates signals:

Question 7

Explain the changes in ion permeability and ion flow that take place during an action potential.

Question 8

Describe and compare absolute and relative refractory periods.

Question 9

Explain the role of myelin in the conduction of action potentials.

Question 10

Distinguish between electrical and chemical synapses.

Question 11

List and give examples of the seven groups of neurocrine secretions.

Question 12

Describe different patterns for neurotransmitter synthesis, recycling, release, and termination of action.

Question 13

Describe the role of the following in synaptic communication: ionotropic and metabotropic receptors, neurotransmitters and neuromodulators, fast and slow synaptic potentials, excitatory and inhibitory postsynaptic potentials.

Question 14

Compare temporal and spatial summation.

Question 15

Compare presynaptic and postsynaptic inhibition.

Question 16

Explain the mechanism of long-term potentiation mediated by AMPA and NMDA receptors.