task 2 - neurons

Question 1

soma

Answer 1

the cell body, contains the nucleus and machinery for the cell to carry out processes

Question 2

dendrites

Answer 2

the antennas, receive messages from other neurons that are transmitted across the synapse

Question 3

synapse

Answer 3

a small space between terminal buttons of the sending cell and a portion of the somatic or dendritic membrane of the receiving cell

Question 4

axon

Answer 4

long thin tube, carries information from the cell body to the terminal buttons (electrical outlet to an appliance!!!!!)

Question 5

terminal buttons

Answer 5

at the end of axons, when action potential is traveling down the axon and reaches them, it secretes a neurotransmitter

Question 6

nodes of ranvier

Answer 6

the gaps between sections of myelin in the axon

Question 7

anterograde axoplasmic transport

Answer 7

movement from the cell body to the terminal buttons (done by kinesin)

Question 8

retrograde exoplasmic transport

Answer 8

movement from the terminal buttons to the cell body (done by dynein)

Question 9

sensory neurons

Answer 9

in PNS they gather information in the form of light, sound waves, odors, tastes, contact with objects

Question 10

motor neurons

Answer 10

controls muscle contraction, creating motor functions

Question 11

interneurons

Answer 11

; in between the sensory and motor neurons, lie entirely within the CNS

Question 12

local interneurons

Answer 12

form circuits w/ nearby neurons and analyze (okay overthinker!!!!)

Question 13

relay interneurons

Answer 13

connect circuits of local interneurons in one region of the brain with other regions of the brain (relay racer!!!!! but for the brain)

Question 14

unipolar neuron

Answer 14

only 1 process extending from it’s cell body, the process branches in 2 directions- one of the ends is an input zone and the other an output zone (transmit touch information from the body into the spinal cord)

Question 15

bipolar neuron

Answer 15

dendrite at the one end of the cell and 1 axon on the other end (common for sensory systems)

Question 16

multipolar neuron

Answer 16

many sets of dendrites and a single axon (99% of neurons) integrate neural activity within a single brain structure

Question 17

nerves

Answer 17

bundles of neurons wrapped in membrane

Question 18

membrane potential

Answer 18

any change in potential energy in the membrane (positive or negative)

Question 19

resting potential

Answer 19

the membrane staying at -70 mV when resting and not communicating with other neurons

Question 20

how does resting potential work?

Answer 20

diffusion and electrostatic pressure

Question 21

hyperpolarization

Answer 21

the inside of an axon becomes more negative from the resting potential relative to the outside

• when the axon becomes more positive than the outside the neuron is depolarized (more likely to send an electrical message)

Question 22

threshold for excitation

Answer 22

for depolarization to trigger the main electrical event in an axon- the action potential

Question 23

action potential

Answer 23

a burst of rapid depolarization to hyperpolarization, this begins at the point where the soma meets the axon and travels down to the end of the terminal buttons, triggering the terminal buttons to release neurotransmitters into the synapse

Question 24

absolute refractory period

Answer 24

the period after the initiation of an action potential, during which it is impossible to elicit a second one (due to blockage of the Na+ channels)

Question 25

all-or-none law

Answer 25

action potential either occurs or does not occur, once triggered its transmitted down the axon to its end

Question 26

rate law

Answer 26

there are variations in the intensity of a stimulus or other info. being transmitted in an axon are represented by variations in the rate at which the axon fires

Question 27

saltatory conduction

Answer 27

hopping from node to node

Question 28

decremental conduction

Answer 28

the axon conducts the electrical signal from the action potential to the next node of ranvier, the signal gets smaller as it passes down the axon

at each node of ranvier, the action potential gets retriggered and the electrical signal that results is conducted decrementally along the myelinated area to the next node of ranvier

Question 29

cations

Answer 29

positively charged ions

Question 30

sodium-potassium pump

Answer 30

active transport, need energy, creates resting potential

Question 31

anions

Answer 31

negatively charged ions

Question 32

ion channels

Answer 32

structures of proteins that permit ions to enter or leave the cells, when open it will permit specific ions to go through

Question 33

voltage-dependent ion channels

Answer 33

only open because of a change in membrane potential

Question 34

glia (nerve glue)

Answer 34

surround neurons and hold them in place, regulating their supply of nutrients and some of the chemicals needed to exchange with other neurons

Question 35

astrocytes

Answer 35

(largest of the glial cells) physical support to neurons and clean up debris w/in the brain, are the glue to hold neurons together

Question 36

what else does the astrocytes do?

Answer 36

• three-way synapses with neighboring neurons and directly participate in the transmission of information between neurons
• control the blood-brain barrier, relax/constrict the blood vessels based on the demand from the brain

Question 37

microglia

Answer 37

(smallest of the glial cells) function like some types of astrocytes but also aid in the immune system in the brain by preventing microorganisms from getting in, inflammatory reaction in response to brain damage

Question 38

oligodendrocytes (CNS)

Answer 38

provide support to axons and produce the myelin sheath (myelination)

• form paddle shaped arms to wrap around the axons

Question 39

schwann cells (PNS)

Answer 39

→ forms myelin sheaths around axons in PNS, they can digest dying and dead axons in turn helps with helping the axon regrow and reform connections