Basics of Cellular Communication

Question 1

what is the functional unit of the nervous system?

Answer 1

neuron/nerve cell

Question 2

what does the Na/K pump do?

Answer 2

actively pumps K+ into the cell and removes Na+ from the cell to maintain 3Na+/2K+

Question 3

what is the range of resting membrane potential?

Answer 3

-30mV to -90mV

Question 4

what is the action potential generated by?

Answer 4

opening of voltage-gated Na+ channels which occurs at the neurons threshold potential

Question 5

what is the resting membrane potential restored by after the action potential?

Answer 5

closure of voltage-gated Na+ channels coupled with K+ channels opening
K+ leaves the cell

Question 6

when do K+ channels close?

Answer 6

approximately the original resting membrane potential

Question 7

where is the action potential initiated?

Answer 7

axon hillock
unidirectional

Question 8

how can graded membrane potentials lead to action potential?

Answer 8

spatial summation
temporal summation

Question 9

what are graded membrane potentials caused by?

Answer 9

synaptic activity: ligand gated ion channels

Question 10

when do voltage sensitive Ca++ channels open?

Answer 10

when the membrane is depolarized by the action potential

Question 11

what does intracellular Ca++ lead to?

Answer 11

neurotransmitter release

Question 12

what must happen for vesicles to release neurotransmitter?

Answer 12

docked near membrane
detect Ca++ levels
fuse with membrane to release contents

Question 13

what type of proteins are involved in many of the processes at the chemical synapse?

Answer 13

SNARE proteins

Question 14

what is the major excitatory neurotransmitter in the brain?

Answer 14

glutamate

Question 15

what is the excitatory neurotransmitter at the neuromuscular junction?

Answer 15

acetylcholine

Question 16

what is the major inhibitory neurotransmitter in the brain?

Answer 16

GABA

Question 17

what type of receptors do neurotransmitters act upon?

Answer 17

receptors that are classified as either ligand-gated ionotropic receptors or G-protein coupled metabotropic receptors

Question 18

how many axons do multipolar neurons have?

Answer 18

one

Question 19

what do biogenic amines do?

Answer 19

effects depend upon what receptor they activate

Question 20

where are bipolar neurons found?

Answer 20

special sensory systems: retina, olfactory epithelium, vestibulocochlear nerve

Question 21

what are unipolar or pseudounipolar neurons like?

Answer 21

two axons rather than dendrites and an axon

Question 22

what do glia do?

Answer 22

provide mechanical and physical support
provide nutrients (oxygen) to neurons
remove cellular debris
remove toxic/bad substances
electrical insulation

Question 23

where do the axons of unipolar/pseudounipolar neurons extend?

Answer 23

one from sensory receptors in periphery
one towards spinal cord

Question 24

what do schwann cells do?

Answer 24

myelinate peripheral axons
provide trophic factors and nutrients
involved in axonal regeneration

Question 25

what do satellite cells do?

Answer 25

support cells of the peripheral nervous system

Question 26

what are microglia?

Answer 26

tissue resident macrophages of the CNS

Question 27

what are microglia responsible for?

Answer 27

immuno-surveillance
immuno-regulation

Question 28

what do oligodendrocytes do?

Answer 28

myelinate axons within the CNS to regulate the speed of electrical conductance

Question 29

what cells play a role in the blood brain barrier?

Answer 29

astrocytes

Question 30

what cells provide the lining of the ventricular cavities in the CNS and central canal of the spinal cord?

Answer 30

ependymal cells

Question 31

what does the plasma membrane of the neuron determine?

Answer 31

morphology

Question 32

are there more K or Na diffusion channels in the neuron?

Answer 32

more K leak channels

Question 33

what is the range of resting membrane potentials?

Answer 33

-30mV to -90mV

Question 34

what type of ion channels cause graded membrane potentials?

Answer 34

ligand gated

Question 35

what are neuronal SNARE proteins involved in?

Answer 35

many of the processes for chemical synapse: vesicle release

Question 36

what do neurotransmitters act on?

Answer 36

receptors: ligand-gated ionotropic receptors or G-protein coupled mechanotropic receptors

Question 37

what are some multipolar neurons?

Answer 37

alpha motor neurons in spinal cord
pyramidal neurons in cerebral cortex

Question 38

describe a bipolar neuron

Answer 38

two processes extend from cell body: dendrites and axon

Question 39

how many primary brain tumors in dogs are gliomas?

Answer 39

35%

Question 40

where are satellite cells found?

Answer 40

peripheral ganglia

Question 41

what are microglia responsible for?

Answer 41

immuno-surveillance and immuno-regulation

Question 42

how many axons can one oligodendrocyte myelinate?

Answer 42

5-6

Question 43

what maintains structural integrity of the CNS following injury resulting in neuronal cell loss?

Answer 43

astrocytes

Question 44

what do ependymal cells do?

Answer 44

produce and circulate cerebrospinal fluid
neural stem cells under certain conditions
source of immune regulators

Question 45

can schwann cells myelinate multiple segments of axons?

Answer 45

no

Question 46

which support cells play a role in neuropathic pain?

Answer 46

satellite cells

Question 47

what cells have a critical role in the clearance of excitatory transmitters and ions from the synaptic cleft?

Answer 47

astrocytes