Nervous System

Question 1

How is information received

Answer 1

Information is received by sensory cells

Question 2

What does the information need to be converted to in order for it to be processed by neuron

Answer 2

Information is converted (transduced) to electrical signals

Question 3

How does the information get passed throughout the body

Answer 3

it is transmitted and processed by neurons

Question 4

What is the purpose of neurons

Answer 4

receive, encode, and transmit information, use electrical impulses (action potentials), chemicals (neurotransmitters)

Question 5

What is the purpose of glial cells

Answer 5

they protect, support, insulate and nourishment of neurons

Question 6

What is the cell body of a neuron

Answer 6

It stores the nucleus and most of the cells organelles

Question 7

What are dendrites and the purpose

Answer 7

They are the lines coming out of the cell body. they receive information from other neurons and sensory cells

Question 8

What is the axon, and its function

Answer 8

the axon is the long part of the neuron. it carries information away from the cell body to target cells

Question 9

What are some of the target cells that neurons transmit information to

Answer 9

other neurons, glands, muscle cells

Question 9

What are some of the target cells that neurons transmit information to

Answer 9

other neurons, glands, muscle cells

Question 10

How do neurotransmitters get released

Answer 10

nerve impulses on the axon terminals cause the release of neurotransmitters into the synapse

Question 11

the nervous system process information in three stages what are they

Answer 11

Sensory input, integration, and motor output

Question 12

What info do sensory neurons transmit

Answer 12

They transmit info about external stimuli like light, touch, or smell

Question 13

What do interneurons do

Answer 13

They integrate (analyze and interpret) the information

Question 14

What do motor neurons do

Answer 14

transmit signals to muscle cells, causing the to contract

Question 15

What are action potentials

Answer 15

neurons communicate by producing electrical signals (action potentials)

Question 16

which signals do neurons transduce over long distances

Answer 16

electrical signals (action potentials). can convert stimuli into electrical pulses

Question 17

which signals do neurons transduce over short distances

Answer 17

chemical signals (neurotransmitters)

Question 18

is a neurons resting potential negative or positive

Answer 18

neurons have a resting negative membrane potential

Question 19

What is the membrane potential of a resting axon

Answer 19

-70 millivolts (mV)

Question 20

is the inside of a cell more negative or positive than the outside

Answer 20

the inside of a cell is more negative

Question 21

What are the major ions that carry electric charges across the plasma membrane

Answer 21

Sodium (Na+), chloride (Cl-), potassium (K+), and calcium (Ca2+)

Question 22

ATP pump controls concentration of ions in and out of cell. what is the ratio of na to k

Answer 22

3 Na+ out, 2 K+ ions in

Question 23

Does the sodium potassium pump more against or down the concentration gradient

Answer 23

Against the gradient meaning it needs ATP

Question 24

Do ion channels need energy for things to flow through

Answer 24

No they don't need energy. Ions can easily flow through

Question 25

How do ion channels choose what passes through

Answer 25

Ion channels selectively allow ions to pass through. If K channel, then only K can go in and out passively

Question 26

How do voltage gated channels open and close

Answer 26

They open or close in response to a change in the voltage across a plasma membrane

Question 27

How do chemically gated channels open and close

Answer 27

they open and close depending on the presence of absence of a specific chemical that binds to the channel proteins

Question 28

When is a cell depolarized

Answer 28

When the inside of a neuron becomes less negative in comparison to its resting condition

Question 29

When is a cell hyper polarized

Answer 29

when the inside of a neuron become more negative in comparison to its resting condition

Question 30

What are primarily responsible for action potentials

Answer 30

Voltage gated sodium channels

Question 31

What is the threshold potential number

Answer 31

It is 5-10 mV above the resting potential

Question 32

what is the purpose of the threshold potential

Answer 32

has to fire to threshold or else no action potential will occur

Question 33

What causes the action potential

Answer 33

results from rapid changes in voltage gated Na+ and K+ channels

Question 34

Do voltage gated potassium channels open faster or slower than sodium channels

Answer 34

voltage gated potassium open slower than sodium channels

Question 35

how does the slower opening potassium channels affect the cell

Answer 35

causes the plasma membrane to return to its resting potential

Question 36

what causes the falling of the action potential

Answer 36

sodium channels close while potassium channels open. potassium flowing out of the cell makes it more negative lowering the action potential until it undershoots

Question 37

is sodium higher on the inside or outside of the cell membrane

Answer 37

sodium is higher on the outside

Question 38

is potassium on the outside or inside of the cell membrane

Answer 38

potassium is higher on the inside of the cell

Question 39

What is the refractory period

Answer 39

channels in the area cant respond to another signals

Question 40

why do action potentials travel forward in one direction

Answer 40

the sodium channel current depolarize next section

Question 41

how does the potassium channel make the action potential flow forward

Answer 41

potassium flows out and k+ channels stay open longer than na+ which is why action potentials only goes forward

Question 42

how long is the refractory period

Answer 42

1-2 milliseconds

Question 43

what is the refractory period

Answer 43

the cells are non responsive so they cannot fire another signal and why they cant go backwards

Question 44

Where are the voltage gated channels located

Answer 44

They are located in the nodes of ranvier (the gaps in the myelin sheath)

Question 45

why is propagation of action potentials so fast

Answer 45

action potentials only fire in nodes so its propagation is much faster

Question 46

What are astrocytes

Answer 46

contribute to the blood brain barrier, protect the Brian from toxic chemicals in the blood. permeable to fat soluble molecules

Question 47

what is the purpose of astrocytes

Answer 47

monitor all changes in blood because neurons don't know what's happening in blood and need to change accordingly 2

Question 48

a disease that destroys myelin produced by oligodendrocytes would most likely cause what

Answer 48

neurons in the brain and spinal cord would conduct action potentials slower

Question 49

how is the resting potential of the nerve cell membrane maintained

Answer 49

the sodium potassium pump keeps the concentration of K inside the cell greater than outside, and the conc of Na outside the cell greater than inside (3 Na out/ 2 k in)

Question 50

a neuron that collects info from a few inputs and transmits it a short distance to another close neuron would have what shape

Answer 50

a few dendrites with a short axon

Question 51

what do graded potentials do

Answer 51

they allow a cell to integrate inputs and respond proportionally

Question 52

what is the cell that is wrapped around the axon of a neuron in the brain, forming concentric layers of plasma membrane

Answer 52

an oligodendrocyte

Question 53

what do oligodendrocytes do

Answer 53

insulate the axon for rapid conduction of action potentials

Question 54

at resting potential, are most of the sodium channels open or closed

Answer 54

They are closed

Question 55

when an action potential is occurring, which way do the ions flow

Answer 55

Na will move into the cell, and K will move out of the cell

Question 56

when you decide to mark a particular answer, your nervous system sends the command to your hand to do so. the command is carried into your hand by axons of which type of neuron

Answer 56

Efferent neurons- motor neurons