nervous system

Question 1

ganglia

Answer 1

many neurons

Question 2

cephalization

Answer 2

creating a concentration of sensory organs and nervous system components at the front of the body

Question 3

pathway of nervous system

Answer 3

sensory (sensory neurons) –> sensory input (PNS) –> integration (CNS) –> motor output (PNS) –> effector

Question 4

sensory neuron

Answer 4

cell body in middle of axon, in PNS

Question 5

interneurons

Answer 5

cell body near dendrites, in CNS

Question 6

motor neurons

Answer 6

cell body near dendrites, in PNS

Question 7

dendrite

Answer 7

receives signals from other nerves, at the top of the cell

Question 8

axon hillock

Answer 8

connects dendrite and axon, where action potential is triggered

Question 9

what is the difference between a nerve cell and other cells?

Answer 9

an axon

Question 10

axon

Answer 10

the long fatty section of the nerve, where the signals are sent down

Question 11

presynaptic cell

Answer 11

cell that is sending the signal, before the signal is sent

Question 12

postsynaptic cell

Answer 12

cell that receives the signal

Question 13

synapse

Answer 13

the gap/connection between two nerves

Question 14

neuron vs nerve

Answer 14

neuron is the functional unit of a nerve, multiple neurons make up a nerve

Question 15

1st step of neuronal signal transduction

Answer 15

stimuli is received by dendrites and cell body

Question 16

2nd step of neuronal signal transduction

Answer 16

synaptic stimuli summoned at axon hillock where an action potential is triggered if the sum of the arriving signals is greater than the threshold

Question 17

3rd step of neuronal signal transduction

Answer 17

action potential conducted along axon and axon terminal where neurotransmitters are released

Question 18

what happens to released neurotransmitters?

Answer 18

they bind to receptors on postsynaptic cell membrane and potentially create a new signal

Question 19

resting membrane potential of a neuron

Answer 19

-70 mV

Question 20

action potential

Answer 20

the depolarization of a cell

Question 21

steps of an action potential

Answer 21

1. reaching threshold, 2. depolarization (Na+ rushes in), 3. repolarization (K+ rushes out), 4. refractory period

Question 22

how does depolarization occur?

Answer 22

there are voltage gated sodium channels that are opened when the threshold is reached, as the membrane potential reaches 40 the channels become blocked

Question 23

how does repolarization occur?

Answer 23

voltage gated potassium channels open and potassium will rush out of the cell

Question 24

inactivation gate

Answer 24

closes the sodium channel so it does not keep working during repolarization

Question 25

glial cell

Answer 25

provide chemical and physical support to other cells

Question 26

myelin sheath

Answer 26

fatty outer layer that promotes movement of action potential

Question 27

salgatory propogation

Answer 27

movement of signal across axon

Question 28

node of ranvier

Answer 28

in between myelin sheath segments there are proteins where the signal is received

Question 29

axon terminal

Answer 29

receives and passes on the signal

Question 30

vesicles role in action potential

Answer 30

store neurotransmitters and exocytose when they should be released into synaptic cleft

Question 31

why do vesicles know when to exocytose?

Answer 31

voltage gated Ca2+ channels open which allows Ca to rush into presynaptic membrane and triggers vesicles

Question 32

what happens when the neurotransmitter (Ach) is released?

Answer 32

Ach binds to protein which opens ion channels for Na+ to rush into postsynaptic membrane

Question 33

astrocyte

Answer 33

type of glial cell, huge component of the CNS

Question 34

role of the astrocyte

Answer 34

structure neuron, repair damaged neurons with scar tissue, maintain homeostasis, creates blood brain barrier

Question 35

EPSP

Answer 35

excitatory signals which depolarize the cell, can have temporal or spacial summation

Question 36

IPSP

Answer 36

inhibitory signals which hyperpolarize the cell

Question 37

temporal summation

Answer 37

multiple EPSPs arrive quickly at a single synapse and set off an action potential

Question 38

spacial summation

Answer 38

several signals at the asme time from different EPSPs leads to action potential

Question 39

afferent neurons

Answer 39

to CNS

Question 40

efferent neurons

Answer 40

away from CNS

Question 41

Peripheral Nervous System (PNS)

Answer 41

made of a network of mainly neurons, anything that is not the brain or the spinal cord

Question 42

Central Nervous System (CNS)

Answer 42

brain and spinal cord

Question 43

branches of the PNS

Answer 43

somatic and autonomic

Question 44

Somatic reponses

Answer 44

voluntary/conscious: reactions, sensing and responding to environment, etc

Question 45

Autonomic responses

Answer 45

involuntary/unconscious, sympathetic and parasympathetic systems

Question 46

Sympathetic system

Answer 46

fight or flight (accelerates heart, stimulates glucose release, inhibition of stomach and intestines)

Question 47

Parasympathetic system

Answer 47

rest and digest (slow heart, stimulates stomach and intestines)