Chapter 2- Nerve Cells and Behavior

Question 1

where is the first place the action potential is seen

Answer 1

axon hillock

Question 2

types of neurons (cells)

Answer 2

1. unipolar
2. bipolar
3. pseudo-unipolar
4. 3 types of multipolar cells
   a. motor neuron of spinal cord
   b. pyrimidal cell of hippocampus
   c. purkinje cell of cerebellum

Question 3

types of neurons (Categories)

Answer 3

sensory neurons
inter neurons
motor neurons

Question 4

glia

Answer 4

neural support system
-astrocytes
microglia
oligodendrocytes
schwann cells
radial glia

Question 5

astrocytes

Answer 5

• wrap around presynaptic termincals of several axons
• help regulate neurochemicals in the synapse
• end feet on capillaries

Question 6

microglia

Answer 6

• remove waste material
• eat viruses, fungi, and microorganisms
• eat waste from damage

Question 7

oligodendrocytes

Answer 7

• CNS only
• make the myelin sheath in the NCNS
• one oligo makes multiple myelin sheaths, wont allow for regrowth

Question 8

schwann cell

Answer 8

-PNS myelin sheath
-allow for regrowth
1 schwann cell to 1 bead myelin

Question 9

radial glia

Answer 9

• especially important during development

- help guide the migrating neurons from where they are born to where they end up

Question 10

knee jerk reflex

Answer 10

• sensory input (hammer)
• sensory detection (sensory neuron)
• motor command (motor neuron)
• behavior (contraction of mm)

Question 11

knee jerk reflex (simple behavior)

Answer 11

• mm spindle detects stretch
• dendritic end in mm spindle
• cell body in DRG
• terminal is in spinal cord
• excitatory synapse with MN
• mm stretch
• secondary connection with inhibitory interneuron, synapse with motor neuron that will inhibit antagonist mm

Question 12

divergence

Answer 12

one sensory neuron sends information to lots of downstream neurons

Question 13

convergence

Answer 13

-many neurons converge on one neuron, many needed to activate AP

Question 14

feed forward inhibition

Answer 14

enhances pathway

inhibits opposing actions (patellar reflex)

Question 15

feedback inhibition

Answer 15

• self regulating

- prevents excessive activation (damage occuring)

Question 16

4 functional regions of neurons

Answer 16

• input (dendrites)
• integrative (axon hillock)
• conductive (axon)
• output (terminal bouton)

Question 17

resting membrane potential

Answer 17

more (-) inside the cell

• more K+ inside the cell along with impermeable anions (-)
• K+ ions diffuse out of cell, impermeable anions left behind which creates a membrane potential
• permeability of neuron determines resting potential, and permeability can change

Question 18

how the MP changes in diff parts of neuron

Answer 18

-hammer hits knee
Na+ diffuses into dendrite (graded potential)
-action potential occurs (all or none, same in all neurons)
-# of Ap
-Time interval
-neurotransmitter release
-Na+ diffuses into cell, diffuses around area, depolarizes area of cell, which opens next gate for Na+ to diffuse in

Question 19

graded potential vs action potential

Answer 19

graded potential is not enough of a stimulus to create the needed action potential to further the communication down the chain of axons