Chapter 5 Flashcards

1
Q

What are the two main divisions of the nervous system? What do each consist of?

A

CNS: brain and spinal cord

PNS: everything outside the CNS (all sensory receptors in skin, motor pathways, internal organs)

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2
Q

What are the divisions of the PNS and what are their functions?

A

somatic nervous system: controls all voluntary functions/movement; conscious movement

autonomic nervous system: controls activities that don’t require conscious control, involving internal organs (ex. breathing, digestion)

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3
Q

What are the divisions of the autonomic NS?

A

sympathetic: fight or flight

parasympathetic: rest and digest

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4
Q

Who was the main individual involved in the field of phrenology?

A

Franz Gall

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5
Q

What were phrenologists interested in?

A

connecting the function of the brain to thought, behaviour and personality

thought you could divide the brain into different regions and each region would be responsible for some aspect of a person’s personality, believed to extend these ideas to human skull too

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6
Q

What did phrenologists get right?

A

brain could be divided into different regions, and each of those could be responsible for a particular kind of behaviour

The larger the region, the more influence that part of the brain had - not incorrect. The more brain area that is responsible for a particular function, the more influential that function will be.

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7
Q

What is the temporal lobe responsible for?

A

Responsible for auditory processing, language & memory, processing of taste and smell

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8
Q

What is the frontal lobe responsible for?

A

Planning, organizing, impulse control
Executive function

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9
Q

What may occur to someone with damage to the frontal lobe?

A

Might have problem with attention, staying on task, or may say things that are inappropriate - may fall under impulse control

Damage can manifest itself into inappropriate behaviours

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10
Q

What is the parietal lobe responsible for?

A

Perception of touch and spatial awareness (and where limbs are in space)

damage to parietal lobe –> may have difficulty coordinating for spatial tasks

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11
Q

What is the occipital lobe responsible for?

A

Visual processing - tells us how important vision is
Recognizing colour, shapes, motion

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12
Q

What is the cerebellum responsible for?

A

Involved in motor coordination

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13
Q

How would damage to the cerebellum affect someone?

A

Damage will affect a person’s ability to undertake motor activity, may be uncoordinated or clumsy

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14
Q

A healthy human brain has approx. how many neurons in it?

A

Approx. 100 billion neurons in human brain

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15
Q

What are gyri, sulci, and fissures?

A

Gyri = bumps

Sulci = indentations/grooves/valleys

Fissure = deep sulcus - often very prominent and named as well

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16
Q

What connects the two hemispheres of the brain?

A

corpus callosum

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17
Q

Are both hemispheres of the brain identical to one another?

A

For the most part
= most notable exception for humans is that language is not present in the same way between both hemispheres

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18
Q

What is the corpus callosum?

A

Information super-highway; sends information back and forth from left and right hemispheres

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19
Q

Know between anterior, posterior, lateral, medial, ventral, dorsal, superior, inferior.

A

superior/inferior = dorsal/ventral

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20
Q

What does anatomical orientation refer to?

A

Neuroimaging orientation

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21
Q

What are the 4 types of anatomical orientation for neuroimaging?

A

Coronal:
Sliced vertically, then looking into what is exposed as a result
(giving you a frontal view of the brain)

Horizontal section:
Sliced lengthwise, then looking down
(giving a dorsal view of the brain)

Sagittal section:
Slicing the brain in half lengthwise and looking in
(giving a very medial view of the brain)
Medial = deep; closer to midline of the brain

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22
Q

What are the 3 layers of meninges?

A

Dura mater
Subarachnoid space - and arachnoid membrane
Pia mater

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23
Q

What is the clear meninge that covers the brain and is the closes layer to the surface of the brain?

A

Pia mater

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24
Q

Where does cerebrospinal fluid flow among the layers of meninges?

A

In the subarachnoid space, below arachnoid membrane

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25
Where is cerebrospinal fluid produced?
in the ventricles of the brain
26
What is the purpose of cerebrospinal fluid?
protective, encasing brain and spinal cord in a fluid helps to cushion the CNS from daily jostling and movement functions as waste removal system
27
What are the 2 types of stroke that are dangerous to blood circulation in the brain?
Ischemic stroke Hemorrhagic stroke (both are serious and potentially fatal)
28
What is an ischemic stroke?
- blockage - area of brain that is no longer receiving ample blood flow, so neurons in that area are being starved of oxygen and as a result they can die
29
What is a hemorrhagic stroke?
refers to a bleed in the brain, ex. ruptured vessel; can result in cell death as well
30
What is the histological approach of studying the brain?
- Most direct approach for studying the brain - Literally brain is sectioned and sliced - Neuronal loss or damage can be examined very directly - Most precise method for studying the brain, especially when it comes to any pathology or damage to the brain - It is a post-mortem method
31
What is the function of PET scanning? What are some advantages/disadvantages?
- PET scans are able to identify areas of the brain that are calling on more blood flow - Looks at compounds within the blood, ex. glucose - Advantage: the person is awake while this is being done, and they can be engaging in some sort of task - If there is a disruption of the brain areas that are responsible for that particular task, then that will show up in a PET scan - For the most part, non-invasive - Negative: does require the injection of a trace chemical into the bloodstream ○ Ex. compound that can identify glucose within the bloodstream
32
What is the function of fMRI?
Functional = person is awake during fMRI and can engage in a task - Can identify whether there is improper blood flow to different regions of the brain while the person is doing a task - Analyzes magnetic properties of blood - Advantage over PET - doesn't require injection of tracer substance; completely non-invasive - advantage - functional
33
How does fMRI analyze magnetic properties of blood?
Blood with more oxygen has different magnetic properties compared to blood with less blood
34
What is near-infrared spectroscopy?
Technique that relies on light shone into the brain through the skull Can identify areas of the brain that are more active during a task, based on the oxygen properties of the blood flow within the brain Negative: limited to a fairly shallow region of the brain - Only a few cm below the skull - Sensitivity is confined to outer layer of brain
35
What are the 3 static imaging techniques that were discussed?
CT scans MRI DTI - diffusion tensor imaging
36
What is computerized tomography?
An x-ray beam is passed through the brain at many different angles, creating different images - static image produced Can be useful for identifying lesions (ex. tumor), useful for identifying if there is a bleed (ex. hemorrhagic stroke)
37
What is an MRI? What is the benefit?
- More detailed than CT - Static image produced - Useful to identify specific kinds of brain tissue
38
What is DTI?
diffusion tensor imaging - relatively recent technique - static image - useful in identifying disruption in pathways within the brain
39
What is EEG?
electroencephalography - Likely the most common method for studying electrical activity in the brain - EEG studies electrical activity in the brain in the form of wave patterns - Technique useful for studying overall electrical activity in the brain - Ex. Different brain waves in sleep ○ More global brain wave patterns
40
What is deep-brain stimulation?
- Electrodes implanted deeper in the brain - Particular area of brain can be targeted - Low voltage electrical currents can be directed to the regions and facilitate different behaviours - Can be used for cases of Parkinson's disease, ex. where cell death has occurred and cell signals are no longer functioning the way they should; Also used to treat epilepsy and other brain disorders
41
What area of the brain is most responsible for complex behaviours vs. unconscious behaviours necessary for survival?
forebrain: - cerebral cortex - responsible for complex behaviours and advanced cognitions (ex. planning) brainstem: - responsible for more basic unconscious behaviours that are critical for survival - basic functioning - damage is typically catastrophic for person
42
What are the 3 parts of the brainstem and their functions?
Medulla: - Responsible for heart rhythm and breathing Damage - most likely not able to breathe on their own Reticular formation: - Collection of fibres within the brainstem that are involved when we sleep and in waking from sleep - arousal/alertness, sleep Pons - Quite prominent in brainstem - Acts as a bridge to the cerebellum - Important for transitioning between different stages of sleep
43
What are the 5 discussed structures of the midbrain?
hypothalamus thalamus amygdala hippocampus basal ganglia
44
What is the function of the hypothalamus?
- Area responsible for release of hormones into bloodstream - Signals from hypothalamus reach different glands that release those hormones - Homeostasis - hunger, temperature, etc.
45
What is the function of the thalamus?
- Sensory hub - Signals from most of senses within your body are going to travel through thalamus on way to different parts of the brain - Receives and relays signals to/from brain
46
What is the function of the amygdala?
- Regulates emotional responses
47
What could result from damage to the amygdala?
Damage to amygdala - person may be unable to identify different emotions, or unable to read the emotional content in a conversation
48
What is the function of the hippocampus?
- responsible for learning and memory - allows us to transition the experiences in moment into long-term memory - also sensitive to damage - targeted early-on in Alzheimer's disease
49
What is the function of the basal ganglia?
- involved in refining movement - contains reward centre of the brain (active in rewarding behaviour, and in drug addiction)
50
Explain the development of the forebrain in humans?
the human brain retains most of the basic features of other less complex mammalian brains (brainstem, midbrain, forebrain) There is substantial differences in the development of the forebrain in humans relative to other mammals.
51
How do humans stand out from other mammals in the forebrain?
contains a lot more neurons and a lot more connections than the forebrains of other mammals. Even though another mammals brain may have more space and greater volume, the human forebrain has a lot more neurons a more connections.
52
Who was more correct in the debate of the smallest unit of brain function?
Santiago Ramon y Cajal
53
What were the differences in the beliefs of Camillo Golgi and Santiago Ramon y Cajal?
Camillo Golgi: smallest unit of brain function was thought to be nerve fibres, and it was the connections between these nerve fibres that allowed higher level functioning like planning, reasoning, language Santiago Ramon y Cajal: his hypothesis was the neuron hypothesis - Thought that the smallest unit of brain function could go smaller than nerve fibres - could go down right to cellular level (individual neurons) - Cajal was right - individual NEURONS = smallest unit
54
Who won the Nobel prize for identifying the smallest unit of brain function?
Both Golgi and Cajal
55
So what is the smallest unit of brain function?
individual neurons
56
What are the 2 ways that neurons communicate?
electrical signals chemical signals
57
Describe structure of a neuron.
58
What is the difference between sensory and motor neurons?
Sensory neurons - usually simplest - Allow us to convert physical signals from the environment, into neural signals that the brain can then interpret Motor neurons: - Contained in spinal cord - Most robust neurons in the body - Have the longest axons because the signals they send require them to travel long distance (also the thickest axons) - They send signals from the spinal cord and allow you to move different parts of your body - Make connections with muscle fibres at different parts of your body
59
What are pyramidal cells?
Neurons contained in the brain Primary cell type within the forebrain - Populate cerebral cortex
60
What are purkinje cells?
- Dense dendritic trees - Only located in cerebellum Part of the reason cerebellum has a distinctive look compared to cortex
61
What is the role of interneurons?
- Pass signals from one neuron to another neuron - Located only in CNS - Usual role is to pass signals from sensory neurons to motor neurons within CNS
62
What are glial cells? What are the types of glial cells?
support cells that support neurons astrocytes, microglial cells, ependymal cells, oligodendrocytes, schwann cells
63
What are astrocytes?
Extract nutrients from the bloodstream (from blood vessels and arteries) that are needed for functioning within neurons - Allow exchange of nutrients from the bloodstream into neurons - Help to reinforce blood vessels and arteries within the brain ○ Help prevent things like rupturing of blood vessels that can cause damage to nearby neurons
64
What are microglial cells?
- Act like caretaker cells ○ Remove waste and debris associated with nearby cell function - Also involved in immune responses within the brain - if there is damage to an area of the brain, microglial cells will come and aid with the repair of the damage
65
What is the role of ependymal cells?
- Line the ventricles within the brain - Located in spinal cord - Produce cerebrospinal fluid that exists in CNS
66
What causes meningitis and hydrocephalus?
Meningitis: infection of the CSF that can find its way into the brain - can be very serious fatal if it goes untreated Hydrocephalus: overproduction of CSF. When CSF isn't being absorbed properly and is being overproduced, it can lead to inflammation in the brain. - untreated, it can lead to brain damage and can be fatal
67
What is the difference between oligodendrocytes and schwann cells?
Oligodendrocytes: Form myelin on axons of neurons within the CNS (brain and spinal cord) Schwann cells: Form the myelin on axons of neurons within the peripheral nervous system (PNS)
68
What is the primary method that neurons communicate?
Through electrical signaling
69
What are the electrical impulses used to signal to other neurons?
action potentials
70
How many electrical signals can a neuron receive each second?
thousands of signals each second
71
Where is an action potential generated?
at the junction of the cell body and the axon
72
How do signals travel along the axon?
axon is covered in myelin, allowing the electrical signal to travel more efficiently; jumps across different sections of myelin known as the nodes of Ranvier
73
Where are neurotransmitters located?
located in axon terminals or terminal buttons
74
At what points do neurons communicate?
at the synpase: gap between axon terminal to dendrites of the receiving neuron
75
What is the purpose of the speed of action potentials?
So we can experience things as they happen, in the moment since neurons communicate so quickly
76
Where are neurotransmitters stored?
in axon terminals, in presynaptic vesicles
77
What triggers the release of neurotransmitters into the synapse?
when action potential reaches the axon terminal
78
Where are the receptors for neurotransmitters located?
on the dendrites of the receiving neuron
79
What is a pre-synaptic vs. post-synaptic neuron?
pre-synaptic neuron: generates the AP post-synaptic neuron (at dendrites): receives the AP
80
What happens to neurotransmitters that are not received by receptors?
They are terminated in one of 3 ways: reuptake, deactivation, or diffusion
81
Describe the 3 types of neurotransmitter termination.
reuptake: neurotransmitter is sucked back up into pre-synaptic neuron, then available for later point deactivation: enzymes within synapse that deactivate the neurotransmitter diffusion: neurotransmitter floats away from synapse, and becomes no longer available in synapse Often collected by microglial cells and transported back in neurons to be used later
82
What are the 2 common ways that drugs can exert neurotransmitter effects at the synapse?
Agonist: drug enhances the function of the neurotransmitter at the synapse OR Antagonist: drug can inhibit or lessen the effect of the function of neurotransmitters at the synapse
83
What is the function of achetylcholine?
- allows for activation and control of different muscles throughout the body - motor neurons in spinal cord contain ACh - critical role in brain for learning and memory - major NT involved in forming memories
84
What are the functions of norepinpherine?
Major neurotransmitter of the sympathetic nervous system, involved in fight or flight response Primary role is to increase HR and blood flow within the body
85
What are the functions of serotonin?
- altering and modulating mood - major neurotransmitter targeted in anti-depressants (which elevate serotonin levels in the brain to elevate mood levels) - also involved in sleep (allowing transition between stages of sleep)
86
Why can it be difficult to define the role of specific neurotransmitters?
because it can do different things in different situations
87
What are the 2 main pathways where dopamine is the major neurotransmitter?
Reward pathway: area of brain active whenever we engage in some sort of rewarding behaviour (something you enjoy); also involved in addictive behaviour Movement pathway: modulating movement in the body
88
Why is dopamine of interest for researchers studying Parkinson's disease?
Of interest for researchers studying Parkinson's disease due to effect on movement pathway. Loss of dopamine neurons within this pathway that results in characteristic symptoms of Parkinson's disease (ex. uncontrollable shaking)
89
What are the 2 common amino acids neurotransmitters?
GABA Glutamate
90
What is the role of GABA?
- Neurotransmitter involved in parasympathetic nervous system - Helps slow things down - When involved in synapse, it is always having an inhibitory effect - Most inhibitory neurotransmitter in NS
91
What is the function of Glutamate?
- Most excitatory neurotransmitter in the NS - Involved in many systems - Always has an excitatory effect
92
What is the most numerous neurotransmitter within the human body?
Glutamate
93
What is the body's natural pain-reliever that is often targeted by opioid drugs?
Endorphins opioid drugs (like morphine, heroin, fentanyl) are agonists for endorphins and are so addictive because of the effects they have on the NS and are often very pleasurable