section 2 nervous system

Question 1

nervous system

Answer 1

brain, spinal cord, peripheral nerves

Question 2

CNS

Answer 2

central nervous system; brain and spinal cord

Question 3

PNS

Answer 3

Peripheral Nervous System, the sensory and motor neurons that connect the CNS to the rest of the body

Question 4

brain lobes

Answer 4

frontal, temporal, parietal, occipital

Question 5

cerebral cortex

Answer 5

outer region of the cerebrum, containing sheets of nerve cells; gray matter of the brain

Question 6

spinal cord

Answer 6

Nerves that run up and down the length of the back and transmit most messages between the body and brain

Question 7

Nerves

Answer 7

bundle of axons in PNS

Question 8

Neuron

Answer 8

a specialized cell transmitting nerve impulses; a nerve cell.

Question 9

sensory neurons

Answer 9

Detect sensory stimuli have sensory nerve endings rather than dendrites. Carry info about noxious stimuli

Question 10

motor neurons

Answer 10

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands therefore have dendrites

Question 11

optic nerve

Answer 11

the nerve that carries neural impulses from the eye to the brain

Question 12

extracellular fluid

Answer 12

fluid outside the cell

Question 13

intracellular fluid

Answer 13

fluid within cells

Question 14

potential difference (voltage)

Answer 14

the difference in electrical charge between two points in a circuit expressed in volts

Question 15

membrane potential

Answer 15

the voltage difference across a membrane

Question 16

inside the cell

Answer 16

More negative than the outside of the cell

Question 17

1 second

Answer 17

1000 milliseconds

Question 18

action potential

Answer 18

a neural impulse; a brief electrical charge that travels down an axon from axon hillock toward axon terminals

Question 19

Depolarization

Answer 19

The process during the action potential when sodium is rushing into the cell causing the interior to become more positive.

Question 20

concentration gradient

Answer 20

difference in the concentration of a substance from one location to another

Question 21

Length of action potential

Answer 21

2ms

Question 22

Size of action potential

Answer 22

Always the same size, change always from -70 mV to +30mV

Question 23

firing frequency

Answer 23

Rate of producing of action potential per second s(-1)

Question 24

Stability of action potential

Answer 24

Stable signals,

Can travel great distances without fading

Axon of some neurons very long. Toe to spinal cord

Question 25

Synapse

Answer 25

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron

Question 26

presynaptic neuron

Answer 26

neuron that sends the signal

Question 27

postsynaptic neuron

Answer 27

the neuron on the receiving end of the synapse

Question 28

Neurotransmitters

Answer 28

chemical messengers that cross the synaptic gaps between neurons

Question 29

Glutamate

Answer 29

A major excitatory neurotransmitter; involved in memory

Question 30

GABA

Answer 30

An inhibitory neurotransmitter in the brain. Gamma amino butyric acid

Question 31

excitory postsynaptic potential

Answer 31

EPSP- graded depolariztion caused by the arrival of a neurotransmitter at the postsynaptic membrane.

Question 32

inhibitory postsynaptic potential (IPSP)

Answer 32

an inhibitory hyperpolarization of the postsynaptic membrane of a synapse caused by the liberation of a neurotransmitter by the terminal button

Question 33

What happens to neurotransmitter

Answer 33

Diffuse away from synapse

Broken down by enzymes

Taken back up into the axon terminal from which it was realised

Question 34

temporal summation

Answer 34

Summation by a postsynaptic cell of input (EPSPs or IPSPs) from a single source over time.

Question 35

spatial summation

Answer 35

Integration by a postsynaptic neuron of inputs (EPSPs and IPSPs) from multiple sources.

Question 36

Polarised

Answer 36

difference in electrical charge across the membrane