Ch2-Nerve Cells & Nerve Impulses

Question 1

cells which receive info from & transmit info to other cells

Answer 1

neurons

Question 2

cells that do not transfer info over long distances, but exchange chemicals with adjacent neurons

Answer 2

glia

Question 3

one of the 2 main founders of neuroscience who discovered the synapse

Answer 3

Santiago Ramon y Cajal

Question 4

structure that separates the inside of the cell from the outside environment

Answer 4

membrane a.k.a. plasma membrane

Question 5

structure that contains the chromosomes

Answer 5

nucleus (DNA center)

Question 6

structure that performs metabolic activities

Answer 6

mitochondrion

Question 7

sites at which the cells synthesize new proteins

Answer 7

ribosomes

Question 8

network of thin tubes that transport newly synthesized proteins to other locations

Answer 8

endoplasmic reticulum

Question 9

received excitation through its dendrites & conducts messages along its axon to a muscle (soma in spinal cord)

Answer 9

motor neuron

Question 10

contains nucleus, ribosome, mitochondria

Answer 10

cell body a.k.a soma

Question 11

specialized to detect a particular type of stimulation (taste, touch)

Answer 11

sensory neuron

Question 12

receives info from neurons

Answer 12

dendrites

Question 13

increase dendrite surface area available for synapses

Answer 13

dendritic spines

Question 14

conveys messages to other neurons, organs, or muscles

Answer 14

axon

Question 15

insulating sheath covering the axon

Answer 15

myelin sheath

Question 16

short unmyelinated section of axon between segments of myelin

Answer 16

nodes of ranvier

Question 17

point from which axon releases chemicals that cross through junction between one neuron & the next

Answer 17

presynaptic terminal (end bulb)

Question 18

neuron whose axons & dendrites are all contained within one structure

Answer 18

interneuron

Question 19

star-shaped glia that wrap around the presynaptic terminals of functionally related axons; help synchronize activity

Answer 19

astrocytes

Question 20

removes waste material, viruses, fungi, & other mircroorganisms

Answer 20

microglia

Question 21

cell in the brain & spinal cord that build myelin sheaths

Answer 21

oligodendrocytes

Question 22

cells in the periphery that build myelin sheaths

Answer 22

schwann cells

Question 23

guide the migration of neurons during embryonic developments

Answer 23

radial glia

Question 24

mechanism that keeps most chemicals out of the vertebrate brain

Answer 24

blood-brain barrier

Question 25

what cells form the walls of the capillaries

Answer 25

endothelial

Question 26

protein mediated process that expands energy to pump chemicals from blood to brain

Answer 26

active transport

Question 27

electrical message transmitted down the axon of a neuron

Answer 27

nerve impulse

Question 28

difference in voltage in resting neuron; slightly negative due to proteins inside cell

Answer 28

resting potential

Question 29

difference in electrical charge between inside & outside of cell

Answer 29

electrical gradient

Question 30

difference in electrical charge between two locations

Answer 30

polarization

Question 31

protein complex that repeatedly transports 2 sodium ions (na+) out of the cell while drawing in 2 potassium ions

Answer 31

sodium-potassium pump

Question 32

difference in distribution of ions across membraine

Answer 32

concentration gradient

Question 33

increase polarization (moves farther from 0)

Answer 33

hyperpolarization

Question 34

decrease polarization (moves closer to 0)

Answer 34

depolarization

Question 35

level beyond which stimulation of a neuron will produce massive depolarization allowing rapid flow of sodium ions across membrane

Answer 35

threshold of excitation

Question 36

rapid depolarization & slight reversal of the usual polarization

Answer 36

action potential

Question 37

membrane channels whose permeability depends on the voltage differences across the membrane

Answer 37

voltage-gated channels

Question 38

the amplitude & velocity of an action potential are independent the intensity of the stimulus that initiated it

Answer 38

all-or-none law

Question 39

time during which a cell resists the production of a further action potential

Answer 39

refractory period

Question 40

membrane cannot produce an action potential regardless of stimulation

Answer 40

absolute refractory period

Question 41

a stronger than usual stimulation is required to produce action potential

Answer 41

relative refractory period

Question 42

swelling where the axon exits the soma

Answer 42

axon hillock

Question 43

transmission of an action potential down the axon (series of action potentials)

Answer 43

propagation of the action potential

Question 44

those covered with a myelin sheath

Answer 44

myelinated axons

Question 45

flow of action potential from one node of ranvier to another

Answer 45

saltatory conduction

Question 46

neurons without axons; exchange info with only closest neurons (do not follow all-or-none law)

Answer 46

local neurons

Question 47

membrane potentials that vary in magnitude without following the all-or-none law (decay over time)

Answer 47

graded potentials