Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Foundation in Biology - Term 1 Part 1 > 4 - Nervous System > Flashcards

4 - Nervous System Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

In what type of animals is the nervous system found in?

A

Multicellular animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe the cells found in the nervous system (& their features)

A
  • Nerve cells or ‘neurones’
  • Highly differentiated (can’t divide & reproduce) & specialised cells
  • Electrically excitable cells (change in membrane voltage required for cell response)
  • Use synapses to communicate with other cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does the nervous system do?

A

Coordinate sensory info from the body or the environment w/ the resulting actions from diff. parts of the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Name the 3 parts of a neurone

A
  • Cell body
  • Dendrites
  • Axon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is found in the cell body of a neurone?

A

Organelles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the function of dendrites

A

Receive signals from other neurones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the function of an axon

A

transmits signals to other neurones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the function of a synapse

A

Allows info to pass onto next cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Name the two types of nervous system

A
  • Central Nervous System (CNS)

- Peripheral Nervous System (PNS)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Name the main parts of the CNS

A
  • Brain

- Spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Name the main parts of the PNS

A
  • Cranial nerves
  • Spinal nerves
  • Ganglia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe how the CNS is organised

A
  • The CNS is composed of white & grey matter
  • White matter -> centre of the brain
  • Grey matter -> centre of spinal cord
  • Both also have cavities that are filled with CSF
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is white matter?

A

Bundles of axons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is grey matter?

A

Cell bodies (w/ nuclei)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does CSF stand for? Give its function

A

CSF = Cerebrospinal fluid

It carries nutrients & waste (also removes waste)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Name the three regions of the vertebrate brain

A
  • Forebrain
  • Midbrain
  • Hindbrain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the function of the forebrain

A

Regulates sleep, olfactory inputs, learning & complex processing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe the function of the midbrain

A

Coordinates sensory input - sends signals to the forebrain to act on the stimuli that the midbrain has detected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe the function of the hindbrain

A

Coordinates involuntary activities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Explain the importance of the sensory system

A

Detects stimuli (e.g temp, pain) & relays info from the body or the environment to the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Explain the importance of the integrative system

A

Connects CNS & PNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Name the type of neurones that make up the sensory system

A

‘Afferent’ neurones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Name the type of neurones that make up the integrative system

A

‘Interneurones’ (most abundant neurones in the body)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe the function & features of sensory neurones

A
  • Activated by sensory input from the environment (e.g heat, pain etc.)
  • Most are pseudo-unipolar (only have one axon split into two branches)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are sensory receptors?

A

The specialised part of sensory neurones that allow external stimuli to be detected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Name the 5 types of sensory receptors

A
  • Mechanoreceptors
  • Thermoreceptors
  • Chemoreceptors
  • Nociceptors
  • Proprioceptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Give the stimulus for mechanoreceptors

A

Physical force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Give the stimulus for thermoreceptors

A

Temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Give the stimulus for chemoreceptors

A

Dissolved chemicals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Give the stimulus for nociceptors

A

Pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Give the stimulus for proprioceptors

A

Positional info (adapt to positioning of the body)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Describe the the function of interneurones

A
  • They connect motor & sensory neurones and transfer signals btw. them
  • They can also communicate w/ each other & form circuits
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Where are interneurones in most animals found?

A

CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the main feature of neurones that transmit? (interneurones)

A

Highly branched axons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the main feature of neurones that receive? (interneurones)

A

Highly branched dendrites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Name the two systems that make up the PNS

A
  • Somatic (motor)

- Autonomic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Describe the function of the PNS

A
  • Relays info from the CNS to the body

- Controls skeletal muscles & gland secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Name the neurones that make up the somatic systems

A

Afferent sensory neurones & efferent motor neurones

efferent - ‘exit’ the nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What does the somatic system do?

A

Controls voluntary actions i.e. skeletal muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What does the autonomic nervous system do?

A

Controls involuntary actions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Name the 3 divisions of the autonomic nervous system

A
  • Sympathetic
  • Parasympathetic
  • Enteric
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What response is produced by the sympathetic division?

A

‘fight or flight’ (involuntary)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What response is produced by the parasympathetic division?

A

‘rest & digest’ (involuntary)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the function of the enteric nervous system?

A

Controlling the gut smooth muscles & secreting of the associated organs (e.g. pancreas)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Give an example of what response the sympathetic division can produce in the body

A
  • Increase heart rate

- Breakdown glycogen

46
Q

Give an example of what response the parasympathetic division can produce in the body

A
  • Decrease heart rate

- Synthesise glycogen

47
Q

Describe the functions of motor neurones

A
  • Part of the CNS and connect muscles, glands & organs throughout body
  • Transmit impulses from spinal cord to skeletal muscles to control movement
48
Q

Where do the lower motor neurones travel to & from?

A

Travel from spinal cord to muscle

49
Q

Where do the upper motor neurones travel to & from?

A

Travel btw. the brain & spinal cord

50
Q

What is the main structural feature of motor neurones?

A

They are multipolar - one axon & several dendrites

51
Q

Name other supporting cells found in the brain

A
  • Glial cells (or neuroglia)
  • Astrocytes (macroglia)
  • Microglia
  • Oligodendrocytes
  • Schwann cells
  • Ependymal cells
52
Q

Describe the function of glial cells

A
  • Involved in feeding, insulating & protecting the neurones

- Can also divide & reproduce

53
Q

How many types of glial cell are there?

A

5

54
Q

How can the size of glial cells compare to neurones?

A

Glial cells are smaller than neurones (10 glial cells = 1 neurone)

55
Q

Describe the function of astrocytes (macroglia)

A
  • Feed & support neurones
  • Build the blood/brain barrier
  • Remove dead synapses
56
Q

Describe the function of microglia

A

Remove endogenous dead tissue (tissue originating from the body) & foreign bodies by phagocytosis

57
Q

Describe the function of oligodendrocytes

A

Build the insulating axon myelin sheath in the CNS

58
Q

Describe the function of Schwann cells

A

Build the axon myelin sheath in the PNS

59
Q

Describe the function of ependymal cells

A
  • Line the ventricles of the brain & central canal of the spinal cord
  • Participate in the production of the cerebrospinal fluid
  • Can differentiate into new neurones (but do not divide)
60
Q

Ependymal cells can make an unlimited amount of neurones through neurone regeneration. True or false?

A

False. There is a limited amount of neurone regeneration (once these cells used up, no more)

61
Q

What is the myelin sheath?

A

It is a lipid-rich substance surrounding the axons - act as insulation

62
Q

Name the parts that make up the myelin sheath

A
  • Oligodendrocytes (casing) & Schwann cells (extensions)

- Myelin (wraps nerve in segments)

63
Q

What are the Nodes of Ranvier?

A

Gaps/parts of the axon that are not wrapped in myelin sheath

64
Q

Why are mitochondria spread along the axon?

A

So there is even distribution of energy

65
Q

Explain the importance of the myelin sheath

A
  • Increases speed at which electrical impulses travel along the axon by forcing them to ‘jump’ from one Node of Ranvier to another
  • ‘Fueling station’ for the axon after generation of electrical impulses

(Also coordinates transport of cytoskeletal proteins & organelles)

66
Q

How can knowledge of the myelin sheath help with diagnosis of certain diseases?

A

Demyelination (loss of myelin) is a hallmark of multiple sclerosis & other neurodegenerative diseases

67
Q

How do cells detect signals?

A

Using the protein receptors on their surfaces - receptor cell then decides how to interpret the signal

68
Q

A single cell may be sending and receiving multiple signals at once. True or false?

A

True

69
Q

Describe the distribution of ions in cells at resting potential

A

Inside cell - higher K+ conc.

Outside cell - higher Na+ conc.

70
Q

How is resting potential maintained?

A
  • The gradient is maintained by sodium-potassium pump (which uses ATP to maintain this gradient)
  • These conc. gradients are a form of chemical energy
71
Q

How does a neurone generate a signal?

A
  1. Signal is received by receptor cell
  2. The triggering event leads receptor cell converts signal’s energy into an electrical signal - this is done by letting positively charged ions flow into cell body & depolarising cell membrane
  3. As positive ions flow into the ‘negative’ cell, the diff. btw. the interior & exterior of the cell & thus the cells polarity decreases
  4. If cell body gets positive enough that it can trigger the voltage-gated Na+ channels found in the axon, then the action potential will be sent
72
Q

What is the function of the voltage-gated ion channels?

A
  • They open & close in response to stimuli

- This allows movement of ions & therefore changes membrane

73
Q

Why are ion channels in neurones ‘voltage-gated ion channels’?

A

They open & close when the membrane potential is at a certain level
(Don’t need ATP - respond to change in potential diff. when reaches a certain level)

74
Q

Why does depolarisation occur?

A

Depolarisation happens as a result of a nerve impulse causing Na+ to into the cell

75
Q

What happens at the peak action potential?

A

K+ channels open & the cell becomes hyperpolarised

76
Q

What is the threshold in nerve cells?

A

-55V

77
Q

What happens if sodium ions influx?

A
  • More Na+ channels open as they are voltage gated
  • This temporarily changes the membrane potential significantly
  • Once initiated an AP (action potential) has a magnitude independent of the strength of the stimulus
    (AP are an all or none response)
78
Q

What has to be present in order for an action potential to be generated?

A

A large enough stimulus

79
Q

How is the action potential distributed?

A
  • AP has a constant magnitude & regenerates the same potential in areas of the membrane next to it (adjacent)
  • Therefore, AP can spread for along axons/dendrites for long distance communication
80
Q

What is the refractory period?

A

After an AP been generated there is a lag phase where no more APs can be generated

81
Q

Why does the refractory period occur?

A
  • It is due to inactivation of voltage-gated Na+ channels

- This ensures all AP are the same & sets the max. frequency at which impulses can occur (recovery time)

82
Q

If the stimulus is strong, what does this mean about the frequency of the AP?

A

Strong stimulus = more frequent AP

Small stimulus = less frequent AP

83
Q

All action potentials are the same size (constant magnitude). True or false?

A

True

84
Q

How does the AP travel? (hint: chain reaction)

A
  • Na+ inflow in the rising AP creates current that depolarises the adjacent region
  • This process is repeated until the end of the axon/dendrite (synapse)
    (Magnitude will be equal at every location)
  • The zone immediately behind the AP is in the refractory period so APs can’t go backward
85
Q

Explain what is meant by saltatory conduction & why it occurs

A
  • In myelinated axons, the myelin means voltage-gated Na+ channels are restricted to gaps btw. the myelin called Nodes of Ranvier
  • Therefore, myelin increases AP conduction speed
    (This process is known as saltatory conduction)
86
Q

Describe electrical synapses

A

Electrical synapses have gap junctions & electrical current flows directly from pre to post-synaptic neurone

87
Q

Describe chemical synapses

A

Chemical synapses release chemical neurotransmitter from the presynaptic neurone to the post synaptic cell

88
Q

Are electrical or chemical synapses more numerous?

A

Chemical synapses are by far the most numerous

89
Q

What happens at the synapse?

A
  • Neurotransmitters often bind to ligand-gated ion channels (vesicle fuses w/ membrane & releases neurotransmitters)
  • This opens channels that allow specific ions across the postsynaptic neurone
90
Q

What are the two outcomes of neurotransmitters binding to the ion channels at the synapse?

A

Excitatory postsynaptic potential (EPSP) - K+ & Na+ acts to bring membrane potential to threshold

Inhibitory postsynaptic potential (IPSP) - Cl- acts to do the opposite

91
Q

Describe the post synaptic response

A
  • The cell body receives inputs from hundreds of dendrites (& therefore synapses)
  • Some inhibitory & some excitatory
  • The cell body integrates all of these signals to allow the decision to transmit an AP
92
Q

What does the neurotransmitter molecule do?

A

It can bind to diff. types of receptors that can excite or inhibit the postsynaptic cell

93
Q

Name the 3 methods that neurotransmitter signalling is terminated

A
  • Simple diffusion away from the membrane
  • Recapture by the presynaptic neurone (allows recycling)
  • Enzymatic hydrolysis
94
Q

How many neurotransmitters are there approx.?

A

Over 100

95
Q

What is the most common neurotransmitter?

A

Acetylcholine (ACh)

96
Q

There are 2 major types of ACh receptors w/ different roles. True or false?

A

True

97
Q

The ligand-gated ion channel ACh receptor at the neuromuscular junction triggers…

A

The ligand-gated ion channel ACh receptor at the neuromuscular junction triggers…
ion-channel opening & an EPSP

98
Q

Name at least 2 common amino acids that act as neurotransmitters

A
  • Glutamate
  • GABA (Gamma-aminobutyric acid)
  • Aspartate
  • Glycine
99
Q

Give at least one feature of glutamate

A
  • The most common neurotransmitter w/ ionic & metabotropic (initiates metabolic changes) receptors
  • Key role in memory
  • Contributes to death of neurones after injury (e.g. stroke) through a process called excitotoxicity
100
Q

Give at least one feature of GABA

A
  • Metabolite of glutamate

- Mostly linked to inhibitory synapses

101
Q

Name at least 2 biogenetic amines that act as neurotransmitters

A
  • Noradrenaline
  • Dopamine
    (both originate from amino acid tyrosine)
  • Serotonin (originates from tryptophan)
102
Q

Give one feature of noradrenaline

A

It acts as an excitatory neurotransmitter in the PNS

103
Q

Give at least one feature of dopamine

A

Is mostly confined in the CNS

104
Q

Give at least one feature of serotonin

A
  • Enhances mood, cognition, learning & memory

- Involves in numerous physiological processes such as sleeping, eating, digestion & vasoconstriction

105
Q

Name one of the toxins that affect neurotransmitter systems

A
  • Tetanus

- Botulinum

106
Q

How are depression & mood disorders often treated?

A

Using compounds that increase conc. of the biogenic amines

107
Q

How does valium reduce anxiety?

A

It binds to GABA receptor (increasing inhibitory signalling)

108
Q

What is Alzheimer’s disease?

A

A neurodegenerative disease causing loss of neurones in the brain

109
Q

How does Alzheimer’s work?

A
  • Starts in the hippocampus & spreads in a predictable pattern to other regions of the brain
  • Affects 1st the memory and ability to perform tasks & movements, followed by decline of behavioural, social & verbal skills

(Enlarged ventricles in the brain is a tell-tale sign)

110
Q

What is Parkinson’s disease?

A
  • Neurodegenerative disease

- Caused by neuronal loss in an area of the midbrain (substantia nigra)

111
Q

How does Parkinson’s disease work?

A
  • Causes movement disorder and is characterised by tremors & muscular rigidity
  • Eventually leads to dopamine reduction
    (Also, proteins aggregate into Lewy bodies in neurones)

Foundation in Biology - Term 1 Part 1 (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions