Neurons Flashcards Preview

psychology A > Neurons > Flashcards

Flashcards in Neurons Deck (78):
1

How many neurons in the nervous system?

10-100 billion

2

How many neurons does each neuron communicate with?

1000 neurons

3

What other cell is the brain comprised of and what do they do?

Glial cell - provide nutrients to neurons and structural support to nervous system

4

3 neuron functional levels are:

Motor
Sensory
Interneurons

5

Sensory neurons

Transmit sensory
Info from sensory receptor to brain for processing

6

Motor neurons

Transmits info from brain to muscles, organs with instructions on how to function.

7

Describe and sensory and motor neuron:

Very long - toe all the way to brain

8

Interneuron

Make up most of neurons in brain. Transmit info from one neuron to another

9

Neuron parts

Dendrite, cell body, nucleus

10

Which parts of the neuron receive information from other neurons?

Dendrites and cell body

11

Cell body function

Where all important processing of neurons take place

Can receive information from other neurons in the body

12

Nucleus function

Inside cell body
Contains DNA
Control house for how the neuron is structured and functions

13

Dendrites function

Received information from other neurons

14

Axon

Extends like an arm from cell body
Transmits electrical signal from cell body to terminal buttons

15

Terminal
Buttons

Where information is converted to other neurons

16

Myelin

Axon interspersed with myelin (white matter)

17

Unmyelinated parts of axon are caked?

Node of ranvier

18

Axon hillock

(Shoulder to axon)
Connects cell body to axon

19

Which areas carry out the function action potential

Nodes of ranvier and axon hillock

20

Action potential

Propagates electrical signal from axon hillock to allow information to be transmitted to the dendrites of next cell

21

Gap between terminal buttons of the neuron and dendrites of next neuron is:

Synapse

22

Unipolar neuron

One projection from cell body. Dendrites or axon

23

Neuron structures

Unipolar neuron
Bipolar neuron
Prototypical neuron
Pseudo-unipolar neuron

24

Bi polar neuron describe and fiction

Two projections
Function: visual system

25

Prototypical neuron

Multipolar neuron (many projections)

Most common type of neuron

26

Pseudo unipolar neuron

Only one projection but has both dendrite and axon (T shape)

Function: long sensory and motor neurons travelling the length of the body

27

Grey matter

Cell bodies and dendrites

28

What is an example of white matter in the brain?

Corpus callosum
Communication between hemispheres of the brain - comprised entirely of axons spanning from one part of the brain to the other, thus white matter

29

How does communication occur

A

B

C

A - all info from dendrites culminate in cell body to determine whether or not to transmit (electrical signal)

B - info from axon hillock to terminal buttons (electrical signal)

C - electrical signal in thermal buttons becomes chemical allowing communication across synapse

30

Ion

Molecule or chemical with a positive or negative charge

31

Cation

Positively charged ion

32

Anion

Negatively charged ion

33

Diffusion

Movement of substance from high concentration to low concentration

34

Electrostatic pressure

Passive attraction of oppositely charged ions and repulsion of similarly charged ions

35

Intercellular space

Inside of neuron

36

Extra cellular space

Outside of neuron

37

What makes the cell membrane semi-permeable ?

Opening and closing of ion channels that allow certain ions to go in and out

38

How are ion channels open or closed?

Electrical signals

39

Membrane potential is?

Charge inside neuron relative to outside

40

Restating membrane potential

Intercellular space - negative charge

Extracellular space has positive charge

-70mV

41

What is depolarising and how does it occur?

Charge becomes more positive due to excitatory signal

42

What is hyperpolarise?

Inside of membrane becomes more negative and less positive

43

What is received by dendrites and cell body?

Excitatory and inhibitory potential

44

Cell body and dendrites send signals that cause what to happen happen?

Cell membrane manipulated and causes inhibitory or excitatory potential

45

Graded potential

Dependent on inhibitory or excitatory signal

46

Where are graded potential located?

Axons hillock - waiting for electrical signal and to have the net effect

47

What causes a neuron to fire?

Net effect of excitatory and inhibitory graded potentials that converge at axon hillock

48

Threshold of excitation (when the excitatory effect reaches a certain mV)

-55 to -65mV

49

What triggers action potential?

Overall net effect of graded potential is excitatory and has a large enough magnitude to cause membrane to depolarise to -55 to -65

50

Synaptic cleft

Another name for synapse

51

Presynaptic neuron

Neuron sending chemical signal

52

Post synaptic neuron

Neuron receiving chemical signal

53

List the steps of neuron firing:

Electrical signal from presynaptic neuron propogates down axon —> through terminal buttons of presynaptic cell —> presynaptic cell releases chemicals into synapse —-> chemical traverse synapse and bind to post synaptic neuron—> post synaptic neuron either hyperpolarises or depolarises —-> post synaptic neuron causes excitatory or inhibitory potential

54

ESPS and IPSP

Excitatory postsynaptic potential

Inhibitory postsynaptic potential

55

Neurotransmitters

Chemicals that are released by presynaptic neuron into synapse and bind to postsynaptic neuron

56

What stores neurotransmitters?

Vesicles

57

What triggers vesicles to move towards cell membrane, bind to membrane and release neurotransmitter into the synapse?

Terminal buttons

58

What is it called when specific neurotransmitters bind to specific receptors?

Lock and key principle

59

What happens when the neurotransmitter bonds to receptor in postsynaptic membrane?

It causes EPSP or IPSP by indirectly or directly opening up ion channels in membrane that changes concentration of positive and negative ions in cell

60

How does the neutron know to stop releasing neurotransmitters?

Neurotransmitters can also bind to pre-synaptic neutrons to act as a feedback loop

61

What happens to excess neurotransmitters?

Degrade by enzymes in the synapse to be recycled

62

Effects of drugs 1.

1. Increase or decrease synthesis of neurotransmitter in cell

63

Effects of drugs 2

Could alter how much neurotransmitter is released by cell

64

Effects of drugs 3

Influence amount of neurotransmitter in synapse by manipulating reuptake of neurotransmitter or the enzyme that breaks down the neurotransmitters

65

Effects of drugs 4

Could increase or decrease amount of neurotransmitter receptors in post synaptic neuron

66

Effects of drugs 5

Chemical could pretend to be a neurotransmitter and increase the number of receptors in the post synaptic neuron that are activated

67

Glutamate

Function: often produce EPSPs

Implicates: epilepsy and seizures

Learning and memory

68

GABA (gamma amino buteric acid)

IPSPs

Function: behaviour

Example: alcohol effects the GABA as it inhibits the frontal lobe of your brain which were suppose to control behaviour. Alcohol increases GABA functioning and increases inhibition by activating GABAergic neurotransmitters

69

Which receptor site do drugs that put you to sleep or reduce anxiety target?

GABA

70

Dopamine function

Activates reward pathway

Controls: emotions, motivations, Arousal, movement

71

What can high level of dopamine be linked to?

Schizophrenia

72

What can low levels of dopamine be linked to?

Parkinson’s

73

Serotonin function

Regulation of sleep, mood, arousal, emotions and empathy

74

What is low level of serotonin linked to?

Depression

75

What is one way of increasing serotonin in synapse?

Drugs that block reuptake sites in presynaptic neuron thus increasing amount of serotonin that can bind to postsynaptic neuron

76

Acetylcholine

Function: learning, memory, movement, muscle coordination

77

What is acetylcholine linked to?

Alzheimer’s disease

78

Endorphins

Reduce pain and influence mood