2 Nerve Cells and Nerve Impulses

Question 1

cells which receive information from and transmit information to other cells

Answer 1

neurons

Question 2

cells that do not transfer over long distances, but exchange chemicals with adjacent neurons; sometimes act to oscillate cell activity

Answer 2

glia

Question 3

structure that separates the inside of the cell from the outside environment; also called plasma membrane

Answer 3

membrane

Question 4

structure that contains the chromosomes

Answer 4

nucleus

Question 5

structure that performs metabolic activities

Answer 5

mitochondrion

Question 6

sites at which the cells synthesize new protiens

Answer 6

ribosomes

Question 7

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

Answer 7

endoplasmic reticulum

Question 8

receives excitation through its dendrites and conducts messages along its axon to a muscle
has its soma in the spinal cord

Answer 8

motor neuron

Question 9

specialized to detect a particular type of stimulation

Answer 9

sensory neuron

Question 10

receives information from other neurons

increases the surface area available; the more info it can receive

Answer 10

dentries

Question 11

contains the nucleus, chromosomes, mitochondria, and other structures

Answer 11

cell body (soma)

Question 12

conveys messages to other neurons, organs, or muscles

Answer 12

axon

Question 13

insulating sheath covering the axon

Answer 13

myelin sheath

Question 14

short unmyleinated section of axon between segments of myelin

Answer 14

Nodes of Ranvier

Question 15

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

Answer 15

presynaptic terminal (end bulb)

Question 16

neuron whose axons and dendrites are all contained withing one structure

Answer 16

interneuron

Question 17

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

Answer 17

astrocytes

Question 18

remove waste material, viruses, fungi, and other microorganisms

Answer 18

microglia

Question 19

types of glia in the brain

Answer 19

astrocytes, microglia

Question 20

cells in the brain and spinal cord that build the myelin sheaths

Answer 20

oligodendrocytes

Question 21

cells in the periphery that build the myelin sheaths

in peripheral nervous system

Answer 21

Schwann cells

Question 22

guide the migration of neurons during embryonic development

Answer 22

radial glia

Question 23

mechanism that keeps most chemicals out of the vertebrate brain

keeps out most viruses, bacteria, and harmful chemicals

but also keeps out nutrients and medications

Answer 23

blood-brain barrier

Question 24

glucose, amino acids, and CO2 can make it through _______ cells

Answer 24

endothelial cells

Question 25

_______ gets through the blood-brain barrier

Answer 25

rabies

Question 26

how are vertebrate neurons nourished?

Answer 26

glucose

Question 27

Korsakoff’s syndrome:

Answer 27

severe memory impairment

Question 28

How are nerve impulses transmitted?

the impulse does not travel directly down the axon but is ________ at points along the axon so that it isn’t weakened

Answer 28

regenerated

Question 29

a difference in electrical charge between the inside and outside of a cell

Answer 29

electrical gradient

Question 30

a difference in electrical charge between two locations

Answer 30

polarization

Question 31

cell membrane is selectively ______

Answer 31

permeable

Question 32

protein complex that repeatedly transports three sodium ions out of the cell while drawing in two potassium ions

Answer 32

sodium-potassium pump

Question 33

two forces that act on sodium when neuron is at rest

Answer 33

electrical gradient

concentration gradient

Question 34

difference in charge between inside and outside of cell

Answer 34

electrical gradient

Question 35

difference in distribution of ions across membrane

Answer 35

concentration gradient

Question 36

rapid depolarization and slight reversal of the usual polarization

occur only in axons and cell bodies

Answer 36

action potential

Question 37

the amplitude and velocity of an action potential are independent of the intensity of the stimulus that initiated it
toilet analogy

Answer 37

all-or-none law

Question 38

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

if you flush the toilet you can’t push it twice b/c its still working

Answer 38

refractory period

Question 39

swelling where the axon exits the soma

where action potential begins

Answer 39

axon hillock

Question 40

flow of action potential from one node of Ranvier to another

“jumping of the action potential”

Answer 40

saltatory condution

Question 41

a demyelinating disease

the myelin sheath is destroyed and associated with poor muscle coordination

Answer 41

multiple sclerosis

Question 42

neurons without axons; exchange information only with the closet neurons

have short axons & don’t produce action potential

do not follow all-or-none law

Answer 42

local neurons

Question 43

membrane potentials that vary in magnitude without following the all-or none law

Answer 43

graded potentials