phys exam chap 7

Question 1

neurons

Answer 1

conduct electrical signals

Question 2

neuroglia

Answer 2

support neurons

Question 3

myelin

Answer 3

fatty lipid based sheet, sends signal down neuron faster

Question 4

afferent neurons

Answer 4

sensory impulses from sensory receptors sent INTO CNS

Question 5

efferent neurons

Answer 5

motor impulses sent OUT

Question 6

somatic nervous system

Answer 6

controls voluntary movements

Question 7

autonomic nervous system

Answer 7

stimulates involuntary movement (smooth, cardiac muscle)

Question 8

schwann cells

Answer 8

in PNS, produce myelin, form regeneration on damaged axons

Question 9

oligodendrocytes

Answer 9

in CNS, myelinate cells in CNS ONLY

Question 10

astrocytes

Answer 10

CNS, regulate external environments of neurons, connects blood vessels to neruons

Question 11

microglia

Answer 11

CNS, phagocytose foreign materials

Question 12

ependymal cells

Answer 12

produce CSF, line ventricles of brain

Question 13

can CNS regenerate a neuron

Answer 13

no

Question 14

how does PNS regenerate a neuron

Answer 14

the severed part breaks down, and a regeneration tube is formed by schwann cells, neuron regrows & resynapse

Question 15

polarization

Answer 15

membrane potential other than 0mv

Question 16

depolarization

Answer 16

less negative than resting membrane potential (-70)

Question 17

repolarization

Answer 17

membrane returns to resting potential (-70)

Question 18

hyperpolarization

Answer 18

more negative than resting membrane potential (-70)

Question 19

ligand gated channels

Answer 19

open when neuron in binded to receptor

Question 20

voltage gated channels

Answer 20

opens when there is a change in membrane potential, ATLEAST -55

Question 21

graded potential

Answer 21

if mv does not reach threshold

Question 22

action potential

Answer 22

mv reaches threshold

Question 23

absolute action potential

Answer 23

can NOT generate another action potential

Question 24

relative action potential

Answer 24

CAN activate another action potential, needs a stronger stimulus to bring back to threshold

Question 25

saltatory conduction

Answer 25

action potential skips across nodes because of myleination

Question 26

excitatory postsynaptic potential

Answer 26

postsynaptic cell membrane DEPOLARIZES

Question 27

inhibitory postsynaptic potential

Answer 27

postsynaptic cell membrane HYPERPOLARIZES, more difficult for neuron to fire, mainly Cl- channels

Question 28

convergence

Answer 28

many neurons communicating with one neuron

Question 29

divergence

Answer 29

one neuron sending out many signals

Question 30

temporal summation

Answer 30

multiple AP travels down pre-synap sending many signals

Question 31

spatial summation

Answer 31

multiple pre-synap sending signals at the same time