Nervous System

Question 1

Resting potential Maintained by:

Answer 1

3 Na+ pumped out for every 2 K+ in

Question 2

Action Potential

Answer 2

stimulus acts on the neuron, depolarizing the membrane of the cell body

Question 3

Impulse Propagation

Answer 3

Depolarization (Na+ rushing into axon) followed by repolarization (K+ rushing out of axon) along the nerve axon

Question 4

The Synapse

Answer 4

Voltage gates Ca2+ channels open, sending Ca2+ into the cell
Vesicles fuse with presynaptic membrane sending the neurotransmitter across the synaptic cleft
Neurotransmitter binds to receptors on the postsynaptic membrane, triggering depolarization

Question 5

Soma of a Neuron

Answer 5

cell body, contains ER, nucleus, ribosomes

Question 6

Dendrites

Answer 6

appendages that emanate from the soma and receive incoming signals

Question 7

Axon hillock

Answer 7

receives info from dendrites and integrates it and sums the incoming signals to determines if the action potential will fire

Question 8

Axon

Answer 8

long appendage that terminates in close proximity to a target structure

Question 9

Myelin Sheath

Answer 9

Insulates the nerve fibers to increase conduction speed

Question 10

Oligodendrocytes

Answer 10

produce myelin in the CNS

Question 11

Schwann Cells

Answer 11

produce myelin in the PNS

Question 12

Synapse

Answer 12

Composed of the nerve terminal, synaptic cleft, and postsynaptic membrane

Question 13

Ganglia

Answer 13

groups of cell bodies in the PNS

Question 14

Nuclei

Answer 14

groups of cell bodies in the CNS

Question 15

Glial Cells

Answer 15

structural and supportive roles

Question 16

Astrocytes

Answer 16

nourish neurons and form the blood-brain barrier

Question 17

Ependymal Cells

Answer 17

line the ventricles of the brain and produce cerebrospinal fluid

Question 18

Microglia

Answer 18

phagocytic cells in the CNS

Question 19

Temporal Summation

Answer 19

multiple signals integrated in a short period of time

Question 20

Spatial Summation

Answer 20

additive effects based on # and location of incoming signals

Question 21

Absolute Refractory Period

Answer 21

no amount of stimulation can cause another action potential

Question 22

Relative Refractory Period

Answer 22

must be greater than normal stimulation to cause action potential

Question 23

Factors Affecting Speed of AP

Answer 23

length of axon (longer=slower)

cross sectional area of axon (narrow= slower)

Question 24

Three Ways to Remove Neurotransmitters from the Cleft

Answer 24

broken down by enzymatic reaction
brought back into presynaptic neuron using reuptake carriers
diffuse out of the cleft

Question 25

Afferent Neurons

Answer 25

aka sensory neurons

transmit information from receptors to spinal cord and brain, enter on the dorsal side

Question 26

Efferent Neruons

Answer 26

aka motor neruons

transmit motor info from brain and spinal cord to muscles/glands, exit on the ventral side

Question 27

Interneurons

Answer 27

found in between afferent and efferent neurons, and are predominately found in the brain and spinal cords… often linked to reflexive behaviour